INTRODUCTION — People with diabetes have an important role in their own medical care, and self-glucose monitoring is an opportunity for people with diabetes to take control of their health.
Although diabetes is a chronic condition, it can usually be controlled with lifestyle changes and medication. The main goal of treatment is to keep blood glucose levels in the normal or near-normal range. Monitoring blood glucose levels is one of the best ways of determining how well a diabetes treatment plan is working. (See "Patient information: Lifestyle modifications in type 2 diabetes" and see "Patient information: Diabetes type 1: Insulin treatment").
A healthcare provider will periodically order laboratory blood tests to determine blood glucose levels and hemoglobin A1c (A1C). The results of these tests gives an overall sense of how blood glucose levels are controlled (show figure 1). However, fine-tuning of blood glucose levels and treatment also requires that patients monitor their own blood glucose levels on a day-to-day basis.
Self-blood glucose monitoring allows patients to know their blood glucose level at any time and helps prevent the immediate and potentially serious consequences of very high or very low blood glucose. Monitoring also enables tighter blood glucose control, which decreases the long-term risks of diabetic complications.
HOW TO TEST — The following steps include general guidelines for testing blood glucose levels; specific details for individual blood glucose monitors should be obtained from the package insert or a healthcare provider. Wash hands with soap and warm water. Dry hands. Prepare the lancing device by inserting a fresh lancet. Lancets that are used more than once are not as sharp as a new lancet, and can cause more pain and injury to the skin. Prepare the blood glucose meter and test strip (instructions for this depend upon the type of glucose meter used). Use the lancing device to obtain a small drop of blood from the fingertip or alternate site (like the skin of the forearm) (show picture 1). Alternate sites are often less painful than the fingertip. However, results from alternate sites are not as accurate as fingertip samples when the blood glucose is rising or falling rapidly (show picture 2).
Patients who have difficulty getting a good drop of blood from the fingertip can try rinsing the fingers with warm water, shaking the hand below the waist, or squeezing ("milking") the fingertip. Apply the blood drop to the test strip in the blood glucose meter. The results will be displayed on the meter after several seconds. Dispose of the used lancet in a puncture-resistant sharps container (not in household trash).
FREQUENCY OF TESTING — Studies have proven that patients with type 1 and 2 diabetes who maintain normal or near normal blood glucose levels have a lower risk of diabetes-related complications. The frequency of monitoring will depend upon the type of diabetes (1 or 2) and treatment used (insulin versus oral medications).
Type 1 diabetes — For patients with type 1 diabetes, frequent testing is the only way to safely and effectively manage blood glucose levels. (See "Patient information: Diabetes mellitus, type 1").
The recommended frequency of testing varies from patient to patient, though most patients need to test at least four times per day. Patients using intensive insulin therapy and women with type 1 diabetes who are pregnant may need to test as many as seven times per day.
Patients who test frequently, especially those using intensive insulin therapy, may consider purchasing several blood glucose monitors to keep at home, work, school, or in a purse or backpack. This allows a patient easier access to testing equipment, which can increase testing frequency and therefore improve blood glucose control. However, patients who like to track data using meters with a memory function may have difficulty if some blood glucose results are on one meter and others are on a different meter.
Type 2 diabetes — Blood glucose monitoring is also important for patients with type 2 diabetes. The recommendations for frequency of testing varies from one patient to another based upon individual factors such as type of treatment (diet versus oral medication versus insulin), level of hemoglobin A1c (A1C), and treatment goals. A healthcare provider can help a patient know how frequently they should test. (See "Patient information: Diabetes mellitus, type 2").
INTERPRETING RESULTS
Blood glucose testing — The results of blood glucose testing indicate if diabetes treatments are on target. However, blood glucose results can be affected by activity levels, foods eaten, and medications (include insulin and oral diabetes medications). To interpret results, patients must consider all of these potential factors.
Patients should discuss their blood glucose results and the best way to interpret them with a healthcare provider. Patients should understand how to record results (either with paper and pen or electronically) and how to use them to optimally control blood glucose levels. Many meters have a memory function that allows results to be stored and downloaded to a computer. Results can then be analyzed and printed for a healthcare provider to review. All patients who monitor their blood glucose levels should bring their blood glucose records to each visit with a healthcare provider.
Patients should generally record blood glucose results, the time and date, and dose of medication used; additional notes about food intake, exercise, and difficulties with illness or stress can also be helpful but are not generally required every day.
Several days of monitoring are usually needed to identify daily patterns, which can be used to make lifestyle or medication adjustments. Patients who use intensive insulin therapy should adjust their insulin dose before meals based upon the blood glucose readings (ie, give a higher dose of very-rapid or rapid acting insulin when blood glucose levels are high).
Need for urine testing — People with type 1 diabetes should perform urine testing for ketones if their blood glucose level is above 240 mg/dL (13.3 mmol/L), during periods of illness or stress, or if there are symptoms of ketoacidosis, such as nausea, vomiting, and abdominal pain. Ketones are acids that are formed when the body does not have enough insulin to break down glucose, causing the body to break down fat for energy. Ketones can also develop during illness, if an inadequate amount of glucose is available (due to skipped meals or vomiting). Ketoacidosis occurs when high levels of ketones are present, which can lead to serious complications such as diabetic coma.
Urine ketone testing is done with a dipstick, available in pharmacies without a prescription. Urine can be collected and then tested with the dipstick, or the dipstick may be held in the urine stream. A color change occurs if ketones are present, indicating a trace, small, moderate, or large concentration of ketones. If a moderate to large concentration of ketones is present, the patient should consult with a healthcare provider immediately to determine the best treatment. An additional dose of insulin may be required, or the provider may instruct the patient to go to the nearest emergency room.
ADJUSTING TREATMENT — Home blood glucose monitoring can provide useful and motivating information. However, patients should make slow and careful changes to their treatment, allowing the body time to respond to changes. Most patients will need to consult with their provider frequently as they learn to make adjustments in treatment, especially with insulin. However, with time and experience, most patients are able to learn how to make adjustments on their own.
Patients should avoid making multiple treatment changes at the same time unless instructed to do so by a healthcare provider. Changing one aspect of treatment at a time allows for more careful evaluation of the effects of that change on blood glucose levels. Furthermore, it can take several days before changes are reflected in blood glucose results.
ACCURACY OF HOME GLUCOSE MONITORING — Accuracy refers to the ability of a glucose-measuring system to report a result that reflects the actual blood glucose level. Accuracy can be affected by several factors, including the type of blood glucose strip and monitor.
Patients should check the accuracy of their blood glucose monitor occasionally by bringing it to visits with their healthcare provider when blood work is done. Patients can use their monitor to check the blood glucose at the same time that a laboratory blood glucose level is drawn.
Hospital or office laboratories report glucose levels in a part of the blood, called plasma. Most blood glucose monitors also report plasma results (this should be stated on the test strip or glucose monitor packaging). Older meters reported whole blood glucose results, which can differ from plasma results by as much as 15 percent. Patients who compare their glucose monitor results with those from their provider's laboratory should see no more than a 15 percent difference; larger differences suggest a possible problem with the monitor, blood glucose strips, or monitoring technique.
Blood glucose meters — Blood glucose meters are reasonably accurate. However, there can be some variability from one unit to the next, so it is always wise to exercise caution and common sense when using the readings from these machines. As an example, if a reading seems incompatible with physical symptoms (or lack of symptoms), take a second reading or use an alternate method for testing your blood glucose (such as a different meter). All blood glucose machines are least accurate during episodes of hypoglycemia (low blood sugar).
Blood glucose strips — Some brands of glucose strips have batch-to-batch variations. These variations may require recalibration to the meter every time a new batch of strips is opened. It is also important to be systematic about the storage of glucose strips: never mix different batches of strips together, and quickly recap the container after removing a strip. Individually wrapped strips tend to be more reliable, but are also more expensive.
Alternate site testing — Blood glucose results can be less accurate if sites other than the fingertips are used for testing (eg, arm, hand, leg). This should not be a problem if the patient uses one site exclusively. However, during times when the blood glucose is rising rapidly (such as immediately after food ingestion) or falling rapidly (in response to rapidly acting insulin or exercise), blood glucose results from alternate sites may give significantly delayed results compared with fingerstick readings. In these situations, fingertip testing is preferred.
Help for people with vision impairment — People with vision impairment may have difficulty using glucose meters. Patients with impaired vision can get assistance from the American Association of Diabetes Educators (AADE) at (800) 338-3633.
SELECTING A BLOOD GLUCOSE MONITOR — There is no single blood glucose monitor that is better than others. A number of factors should be considered when choosing a monitor: Expense — Special offers, rebates, and trade-ins are almost always available on blood glucose monitors, making them affordable for most people. However, patients should also check the cost of the supplies that go along with a monitor, including test strips; over time, these will be more costly than the monitor. Many insurance carriers cover the cost of the monitor and/or supplies. Medicare now covers all of the costs of blood glucose monitoring. Ease of use — Some monitors are easier to use than others. Some require a tiny sample of blood, meaning that a smaller and less painful finger stick is possible. Meters vary in how quickly they give the result (some in as little as five seconds). Patients should check with friends or family who have a blood glucose monitor and with their healthcare provider (especially diabetes educators) for a recommendation. Accuracy — Glucose meters take a reading from a drop of blood applied to strip. Older meters require more careful preparation of the strip and leave more room for error. Newer meters perform more of the steps automatically, so there is less room for error. Newer meters typically provide the most reliable monitoring results. Sophistication — Some meters allow entry of events (like eating or exercising) and come with software programs that allow the data to be downloaded to a computer. This is most helpful for persons who test frequently and use intensive insulin treatment.
CONTINUOUS GLUCOSE TESTING — Researchers are currently evaluating continuous, less invasive, and less intrusive methods of glucose testing.
How it works — Continuous glucose monitoring systems (CGMS) use a glucose sensor (contained in a small needle) to determine the level of glucose in the interstial fluid, found between cells under the skin. The sensor wirelessly transmits results to a small recording device (the size of a pager or cell phone), which can be worn on the clothing, carried in a purse, or placed within a short distance of the sensor (eg, a bedside table). The sensor records and displays the blood glucose level every few minutes, allowing the patient to observe the trend of their blood glucose levels. The receiver can also be set to alarm if the blood glucose level is above or below a pre-set level, which can be especially helpful for patients who cannot feel when they have low blood glucose (hypoglycemia).
The sensor must be removed and reinserted in a different area every few days. Patients must continue to measure blood glucose levels with a traditional monitor several times daily to ensure that the continuous monitor is correctly calibrated.
Currently, continuous blood glucose monitors are recommended only for patients with type 1 diabetes who use intensive insulin therapy, often with an insulin pump. A combined insulin pump and continuous glucose monitor is also available.
Drawbacks — The continuous glucose sensors currently available are not as accurate as most blood glucose monitors, especially when blood glucose concentrations are rapidly rising. In one study, over 70 percent of the blood and continuous glucose values differed by 10 percent or more, and 7 percent of the readings differed by over 50 percent [5]. The CGMS tends to be less accurate in the lower glucose range (<70 mg/dL or 3.9 mmol/L) and may be inadequate for reliably detecting hypoglycemia.
Thus, continuous glucose sensing devices should not be relied upon exclusively to give patients information about blood glucose levels. Patients must continue to do several fingersticks daily to calibrate the currently available devices and to verify that the sensor readings are accurate.
In addition, the costs associated with continuous glucose monitors are much greater than those of traditional glucose monitors.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov/)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Hormone Foundation
(www.hormone.org/public/diabetes.cfm, available in English and Spanish)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Faas, A, Schellevis, FG, van Eijk, JT. The efficacy of self-monitoring of blood glucose in NIDDM subjects. Diabetes Care 1997; 20:1482.
2. Nettles, A. User error in blood glucose monitoring. Diabetes Care 1993; 16:946.
3. Self-monitoring of blood glucose. American Diabetes Association. Diabetes Care 1994; 17:81.
4. Most, RS, Gross, AM, Davidson, PC. Richardson, P. The accuracy of glucose monitoring by diabetic individuals in their home setting. Diabetes Educ 1986; 12:24.
5. Metzger, M, Leibowitz, G, Wainstein, J, et al. Reproducibility of glucose measurements using the glucose sensor. Diabetes Care 2002; 25:1185.
Tuesday, October 16, 2007
Self-blood glucose monitoring
INTRODUCTION — People with diabetes have an important role in their own medical care, and self-glucose monitoring is an opportunity for people with diabetes to take control of their health.
Although diabetes is a chronic condition, it can usually be controlled with lifestyle changes and medication. The main goal of treatment is to keep blood glucose levels in the normal or near-normal range. Monitoring blood glucose levels is one of the best ways of determining how well a diabetes treatment plan is working. (See "Patient information: Lifestyle modifications in type 2 diabetes" and see "Patient information: Diabetes type 1: Insulin treatment").
A healthcare provider will periodically order laboratory blood tests to determine blood glucose levels and hemoglobin A1c (A1C). The results of these tests gives an overall sense of how blood glucose levels are controlled (show figure 1). However, fine-tuning of blood glucose levels and treatment also requires that patients monitor their own blood glucose levels on a day-to-day basis.
Self-blood glucose monitoring allows patients to know their blood glucose level at any time and helps prevent the immediate and potentially serious consequences of very high or very low blood glucose. Monitoring also enables tighter blood glucose control, which decreases the long-term risks of diabetic complications.
HOW TO TEST — The following steps include general guidelines for testing blood glucose levels; specific details for individual blood glucose monitors should be obtained from the package insert or a healthcare provider. Wash hands with soap and warm water. Dry hands. Prepare the lancing device by inserting a fresh lancet. Lancets that are used more than once are not as sharp as a new lancet, and can cause more pain and injury to the skin. Prepare the blood glucose meter and test strip (instructions for this depend upon the type of glucose meter used). Use the lancing device to obtain a small drop of blood from the fingertip or alternate site (like the skin of the forearm) (show picture 1). Alternate sites are often less painful than the fingertip. However, results from alternate sites are not as accurate as fingertip samples when the blood glucose is rising or falling rapidly (show picture 2).
Patients who have difficulty getting a good drop of blood from the fingertip can try rinsing the fingers with warm water, shaking the hand below the waist, or squeezing ("milking") the fingertip. Apply the blood drop to the test strip in the blood glucose meter. The results will be displayed on the meter after several seconds. Dispose of the used lancet in a puncture-resistant sharps container (not in household trash).
FREQUENCY OF TESTING — Studies have proven that patients with type 1 and 2 diabetes who maintain normal or near normal blood glucose levels have a lower risk of diabetes-related complications. The frequency of monitoring will depend upon the type of diabetes (1 or 2) and treatment used (insulin versus oral medications).
Type 1 diabetes — For patients with type 1 diabetes, frequent testing is the only way to safely and effectively manage blood glucose levels. (See "Patient information: Diabetes mellitus, type 1").
The recommended frequency of testing varies from patient to patient, though most patients need to test at least four times per day. Patients using intensive insulin therapy and women with type 1 diabetes who are pregnant may need to test as many as seven times per day.
Patients who test frequently, especially those using intensive insulin therapy, may consider purchasing several blood glucose monitors to keep at home, work, school, or in a purse or backpack. This allows a patient easier access to testing equipment, which can increase testing frequency and therefore improve blood glucose control. However, patients who like to track data using meters with a memory function may have difficulty if some blood glucose results are on one meter and others are on a different meter.
Type 2 diabetes — Blood glucose monitoring is also important for patients with type 2 diabetes. The recommendations for frequency of testing varies from one patient to another based upon individual factors such as type of treatment (diet versus oral medication versus insulin), level of hemoglobin A1c (A1C), and treatment goals. A healthcare provider can help a patient know how frequently they should test. (See "Patient information: Diabetes mellitus, type 2").
INTERPRETING RESULTS
Blood glucose testing — The results of blood glucose testing indicate if diabetes treatments are on target. However, blood glucose results can be affected by activity levels, foods eaten, and medications (include insulin and oral diabetes medications). To interpret results, patients must consider all of these potential factors.
Patients should discuss their blood glucose results and the best way to interpret them with a healthcare provider. Patients should understand how to record results (either with paper and pen or electronically) and how to use them to optimally control blood glucose levels. Many meters have a memory function that allows results to be stored and downloaded to a computer. Results can then be analyzed and printed for a healthcare provider to review. All patients who monitor their blood glucose levels should bring their blood glucose records to each visit with a healthcare provider.
Patients should generally record blood glucose results, the time and date, and dose of medication used; additional notes about food intake, exercise, and difficulties with illness or stress can also be helpful but are not generally required every day.
Several days of monitoring are usually needed to identify daily patterns, which can be used to make lifestyle or medication adjustments. Patients who use intensive insulin therapy should adjust their insulin dose before meals based upon the blood glucose readings (ie, give a higher dose of very-rapid or rapid acting insulin when blood glucose levels are high).
Need for urine testing — People with type 1 diabetes should perform urine testing for ketones if their blood glucose level is above 240 mg/dL (13.3 mmol/L), during periods of illness or stress, or if there are symptoms of ketoacidosis, such as nausea, vomiting, and abdominal pain. Ketones are acids that are formed when the body does not have enough insulin to break down glucose, causing the body to break down fat for energy. Ketones can also develop during illness, if an inadequate amount of glucose is available (due to skipped meals or vomiting). Ketoacidosis occurs when high levels of ketones are present, which can lead to serious complications such as diabetic coma.
Urine ketone testing is done with a dipstick, available in pharmacies without a prescription. Urine can be collected and then tested with the dipstick, or the dipstick may be held in the urine stream. A color change occurs if ketones are present, indicating a trace, small, moderate, or large concentration of ketones. If a moderate to large concentration of ketones is present, the patient should consult with a healthcare provider immediately to determine the best treatment. An additional dose of insulin may be required, or the provider may instruct the patient to go to the nearest emergency room.
ADJUSTING TREATMENT — Home blood glucose monitoring can provide useful and motivating information. However, patients should make slow and careful changes to their treatment, allowing the body time to respond to changes. Most patients will need to consult with their provider frequently as they learn to make adjustments in treatment, especially with insulin. However, with time and experience, most patients are able to learn how to make adjustments on their own.
Patients should avoid making multiple treatment changes at the same time unless instructed to do so by a healthcare provider. Changing one aspect of treatment at a time allows for more careful evaluation of the effects of that change on blood glucose levels. Furthermore, it can take several days before changes are reflected in blood glucose results.
ACCURACY OF HOME GLUCOSE MONITORING — Accuracy refers to the ability of a glucose-measuring system to report a result that reflects the actual blood glucose level. Accuracy can be affected by several factors, including the type of blood glucose strip and monitor.
Patients should check the accuracy of their blood glucose monitor occasionally by bringing it to visits with their healthcare provider when blood work is done. Patients can use their monitor to check the blood glucose at the same time that a laboratory blood glucose level is drawn.
Hospital or office laboratories report glucose levels in a part of the blood, called plasma. Most blood glucose monitors also report plasma results (this should be stated on the test strip or glucose monitor packaging). Older meters reported whole blood glucose results, which can differ from plasma results by as much as 15 percent. Patients who compare their glucose monitor results with those from their provider's laboratory should see no more than a 15 percent difference; larger differences suggest a possible problem with the monitor, blood glucose strips, or monitoring technique.
Blood glucose meters — Blood glucose meters are reasonably accurate. However, there can be some variability from one unit to the next, so it is always wise to exercise caution and common sense when using the readings from these machines. As an example, if a reading seems incompatible with physical symptoms (or lack of symptoms), take a second reading or use an alternate method for testing your blood glucose (such as a different meter). All blood glucose machines are least accurate during episodes of hypoglycemia (low blood sugar).
Blood glucose strips — Some brands of glucose strips have batch-to-batch variations. These variations may require recalibration to the meter every time a new batch of strips is opened. It is also important to be systematic about the storage of glucose strips: never mix different batches of strips together, and quickly recap the container after removing a strip. Individually wrapped strips tend to be more reliable, but are also more expensive.
Alternate site testing — Blood glucose results can be less accurate if sites other than the fingertips are used for testing (eg, arm, hand, leg). This should not be a problem if the patient uses one site exclusively. However, during times when the blood glucose is rising rapidly (such as immediately after food ingestion) or falling rapidly (in response to rapidly acting insulin or exercise), blood glucose results from alternate sites may give significantly delayed results compared with fingerstick readings. In these situations, fingertip testing is preferred.
Help for people with vision impairment — People with vision impairment may have difficulty using glucose meters. Patients with impaired vision can get assistance from the American Association of Diabetes Educators (AADE) at (800) 338-3633.
SELECTING A BLOOD GLUCOSE MONITOR — There is no single blood glucose monitor that is better than others. A number of factors should be considered when choosing a monitor: Expense — Special offers, rebates, and trade-ins are almost always available on blood glucose monitors, making them affordable for most people. However, patients should also check the cost of the supplies that go along with a monitor, including test strips; over time, these will be more costly than the monitor. Many insurance carriers cover the cost of the monitor and/or supplies. Medicare now covers all of the costs of blood glucose monitoring. Ease of use — Some monitors are easier to use than others. Some require a tiny sample of blood, meaning that a smaller and less painful finger stick is possible. Meters vary in how quickly they give the result (some in as little as five seconds). Patients should check with friends or family who have a blood glucose monitor and with their healthcare provider (especially diabetes educators) for a recommendation. Accuracy — Glucose meters take a reading from a drop of blood applied to strip. Older meters require more careful preparation of the strip and leave more room for error. Newer meters perform more of the steps automatically, so there is less room for error. Newer meters typically provide the most reliable monitoring results. Sophistication — Some meters allow entry of events (like eating or exercising) and come with software programs that allow the data to be downloaded to a computer. This is most helpful for persons who test frequently and use intensive insulin treatment.
CONTINUOUS GLUCOSE TESTING — Researchers are currently evaluating continuous, less invasive, and less intrusive methods of glucose testing.
How it works — Continuous glucose monitoring systems (CGMS) use a glucose sensor (contained in a small needle) to determine the level of glucose in the interstial fluid, found between cells under the skin. The sensor wirelessly transmits results to a small recording device (the size of a pager or cell phone), which can be worn on the clothing, carried in a purse, or placed within a short distance of the sensor (eg, a bedside table). The sensor records and displays the blood glucose level every few minutes, allowing the patient to observe the trend of their blood glucose levels. The receiver can also be set to alarm if the blood glucose level is above or below a pre-set level, which can be especially helpful for patients who cannot feel when they have low blood glucose (hypoglycemia).
The sensor must be removed and reinserted in a different area every few days. Patients must continue to measure blood glucose levels with a traditional monitor several times daily to ensure that the continuous monitor is correctly calibrated.
Currently, continuous blood glucose monitors are recommended only for patients with type 1 diabetes who use intensive insulin therapy, often with an insulin pump. A combined insulin pump and continuous glucose monitor is also available.
Drawbacks — The continuous glucose sensors currently available are not as accurate as most blood glucose monitors, especially when blood glucose concentrations are rapidly rising. In one study, over 70 percent of the blood and continuous glucose values differed by 10 percent or more, and 7 percent of the readings differed by over 50 percent [5]. The CGMS tends to be less accurate in the lower glucose range (<70 mg/dL or 3.9 mmol/L) and may be inadequate for reliably detecting hypoglycemia.
Thus, continuous glucose sensing devices should not be relied upon exclusively to give patients information about blood glucose levels. Patients must continue to do several fingersticks daily to calibrate the currently available devices and to verify that the sensor readings are accurate.
In addition, the costs associated with continuous glucose monitors are much greater than those of traditional glucose monitors.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov/)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Hormone Foundation
(www.hormone.org/public/diabetes.cfm, available in English and Spanish)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Faas, A, Schellevis, FG, van Eijk, JT. The efficacy of self-monitoring of blood glucose in NIDDM subjects. Diabetes Care 1997; 20:1482.
2. Nettles, A. User error in blood glucose monitoring. Diabetes Care 1993; 16:946.
3. Self-monitoring of blood glucose. American Diabetes Association. Diabetes Care 1994; 17:81.
4. Most, RS, Gross, AM, Davidson, PC. Richardson, P. The accuracy of glucose monitoring by diabetic individuals in their home setting. Diabetes Educ 1986; 12:24.
5. Metzger, M, Leibowitz, G, Wainstein, J, et al. Reproducibility of glucose measurements using the glucose sensor. Diabetes Care 2002; 25:1185.
Although diabetes is a chronic condition, it can usually be controlled with lifestyle changes and medication. The main goal of treatment is to keep blood glucose levels in the normal or near-normal range. Monitoring blood glucose levels is one of the best ways of determining how well a diabetes treatment plan is working. (See "Patient information: Lifestyle modifications in type 2 diabetes" and see "Patient information: Diabetes type 1: Insulin treatment").
A healthcare provider will periodically order laboratory blood tests to determine blood glucose levels and hemoglobin A1c (A1C). The results of these tests gives an overall sense of how blood glucose levels are controlled (show figure 1). However, fine-tuning of blood glucose levels and treatment also requires that patients monitor their own blood glucose levels on a day-to-day basis.
Self-blood glucose monitoring allows patients to know their blood glucose level at any time and helps prevent the immediate and potentially serious consequences of very high or very low blood glucose. Monitoring also enables tighter blood glucose control, which decreases the long-term risks of diabetic complications.
HOW TO TEST — The following steps include general guidelines for testing blood glucose levels; specific details for individual blood glucose monitors should be obtained from the package insert or a healthcare provider. Wash hands with soap and warm water. Dry hands. Prepare the lancing device by inserting a fresh lancet. Lancets that are used more than once are not as sharp as a new lancet, and can cause more pain and injury to the skin. Prepare the blood glucose meter and test strip (instructions for this depend upon the type of glucose meter used). Use the lancing device to obtain a small drop of blood from the fingertip or alternate site (like the skin of the forearm) (show picture 1). Alternate sites are often less painful than the fingertip. However, results from alternate sites are not as accurate as fingertip samples when the blood glucose is rising or falling rapidly (show picture 2).
Patients who have difficulty getting a good drop of blood from the fingertip can try rinsing the fingers with warm water, shaking the hand below the waist, or squeezing ("milking") the fingertip. Apply the blood drop to the test strip in the blood glucose meter. The results will be displayed on the meter after several seconds. Dispose of the used lancet in a puncture-resistant sharps container (not in household trash).
FREQUENCY OF TESTING — Studies have proven that patients with type 1 and 2 diabetes who maintain normal or near normal blood glucose levels have a lower risk of diabetes-related complications. The frequency of monitoring will depend upon the type of diabetes (1 or 2) and treatment used (insulin versus oral medications).
Type 1 diabetes — For patients with type 1 diabetes, frequent testing is the only way to safely and effectively manage blood glucose levels. (See "Patient information: Diabetes mellitus, type 1").
The recommended frequency of testing varies from patient to patient, though most patients need to test at least four times per day. Patients using intensive insulin therapy and women with type 1 diabetes who are pregnant may need to test as many as seven times per day.
Patients who test frequently, especially those using intensive insulin therapy, may consider purchasing several blood glucose monitors to keep at home, work, school, or in a purse or backpack. This allows a patient easier access to testing equipment, which can increase testing frequency and therefore improve blood glucose control. However, patients who like to track data using meters with a memory function may have difficulty if some blood glucose results are on one meter and others are on a different meter.
Type 2 diabetes — Blood glucose monitoring is also important for patients with type 2 diabetes. The recommendations for frequency of testing varies from one patient to another based upon individual factors such as type of treatment (diet versus oral medication versus insulin), level of hemoglobin A1c (A1C), and treatment goals. A healthcare provider can help a patient know how frequently they should test. (See "Patient information: Diabetes mellitus, type 2").
INTERPRETING RESULTS
Blood glucose testing — The results of blood glucose testing indicate if diabetes treatments are on target. However, blood glucose results can be affected by activity levels, foods eaten, and medications (include insulin and oral diabetes medications). To interpret results, patients must consider all of these potential factors.
Patients should discuss their blood glucose results and the best way to interpret them with a healthcare provider. Patients should understand how to record results (either with paper and pen or electronically) and how to use them to optimally control blood glucose levels. Many meters have a memory function that allows results to be stored and downloaded to a computer. Results can then be analyzed and printed for a healthcare provider to review. All patients who monitor their blood glucose levels should bring their blood glucose records to each visit with a healthcare provider.
Patients should generally record blood glucose results, the time and date, and dose of medication used; additional notes about food intake, exercise, and difficulties with illness or stress can also be helpful but are not generally required every day.
Several days of monitoring are usually needed to identify daily patterns, which can be used to make lifestyle or medication adjustments. Patients who use intensive insulin therapy should adjust their insulin dose before meals based upon the blood glucose readings (ie, give a higher dose of very-rapid or rapid acting insulin when blood glucose levels are high).
Need for urine testing — People with type 1 diabetes should perform urine testing for ketones if their blood glucose level is above 240 mg/dL (13.3 mmol/L), during periods of illness or stress, or if there are symptoms of ketoacidosis, such as nausea, vomiting, and abdominal pain. Ketones are acids that are formed when the body does not have enough insulin to break down glucose, causing the body to break down fat for energy. Ketones can also develop during illness, if an inadequate amount of glucose is available (due to skipped meals or vomiting). Ketoacidosis occurs when high levels of ketones are present, which can lead to serious complications such as diabetic coma.
Urine ketone testing is done with a dipstick, available in pharmacies without a prescription. Urine can be collected and then tested with the dipstick, or the dipstick may be held in the urine stream. A color change occurs if ketones are present, indicating a trace, small, moderate, or large concentration of ketones. If a moderate to large concentration of ketones is present, the patient should consult with a healthcare provider immediately to determine the best treatment. An additional dose of insulin may be required, or the provider may instruct the patient to go to the nearest emergency room.
ADJUSTING TREATMENT — Home blood glucose monitoring can provide useful and motivating information. However, patients should make slow and careful changes to their treatment, allowing the body time to respond to changes. Most patients will need to consult with their provider frequently as they learn to make adjustments in treatment, especially with insulin. However, with time and experience, most patients are able to learn how to make adjustments on their own.
Patients should avoid making multiple treatment changes at the same time unless instructed to do so by a healthcare provider. Changing one aspect of treatment at a time allows for more careful evaluation of the effects of that change on blood glucose levels. Furthermore, it can take several days before changes are reflected in blood glucose results.
ACCURACY OF HOME GLUCOSE MONITORING — Accuracy refers to the ability of a glucose-measuring system to report a result that reflects the actual blood glucose level. Accuracy can be affected by several factors, including the type of blood glucose strip and monitor.
Patients should check the accuracy of their blood glucose monitor occasionally by bringing it to visits with their healthcare provider when blood work is done. Patients can use their monitor to check the blood glucose at the same time that a laboratory blood glucose level is drawn.
Hospital or office laboratories report glucose levels in a part of the blood, called plasma. Most blood glucose monitors also report plasma results (this should be stated on the test strip or glucose monitor packaging). Older meters reported whole blood glucose results, which can differ from plasma results by as much as 15 percent. Patients who compare their glucose monitor results with those from their provider's laboratory should see no more than a 15 percent difference; larger differences suggest a possible problem with the monitor, blood glucose strips, or monitoring technique.
Blood glucose meters — Blood glucose meters are reasonably accurate. However, there can be some variability from one unit to the next, so it is always wise to exercise caution and common sense when using the readings from these machines. As an example, if a reading seems incompatible with physical symptoms (or lack of symptoms), take a second reading or use an alternate method for testing your blood glucose (such as a different meter). All blood glucose machines are least accurate during episodes of hypoglycemia (low blood sugar).
Blood glucose strips — Some brands of glucose strips have batch-to-batch variations. These variations may require recalibration to the meter every time a new batch of strips is opened. It is also important to be systematic about the storage of glucose strips: never mix different batches of strips together, and quickly recap the container after removing a strip. Individually wrapped strips tend to be more reliable, but are also more expensive.
Alternate site testing — Blood glucose results can be less accurate if sites other than the fingertips are used for testing (eg, arm, hand, leg). This should not be a problem if the patient uses one site exclusively. However, during times when the blood glucose is rising rapidly (such as immediately after food ingestion) or falling rapidly (in response to rapidly acting insulin or exercise), blood glucose results from alternate sites may give significantly delayed results compared with fingerstick readings. In these situations, fingertip testing is preferred.
Help for people with vision impairment — People with vision impairment may have difficulty using glucose meters. Patients with impaired vision can get assistance from the American Association of Diabetes Educators (AADE) at (800) 338-3633.
SELECTING A BLOOD GLUCOSE MONITOR — There is no single blood glucose monitor that is better than others. A number of factors should be considered when choosing a monitor: Expense — Special offers, rebates, and trade-ins are almost always available on blood glucose monitors, making them affordable for most people. However, patients should also check the cost of the supplies that go along with a monitor, including test strips; over time, these will be more costly than the monitor. Many insurance carriers cover the cost of the monitor and/or supplies. Medicare now covers all of the costs of blood glucose monitoring. Ease of use — Some monitors are easier to use than others. Some require a tiny sample of blood, meaning that a smaller and less painful finger stick is possible. Meters vary in how quickly they give the result (some in as little as five seconds). Patients should check with friends or family who have a blood glucose monitor and with their healthcare provider (especially diabetes educators) for a recommendation. Accuracy — Glucose meters take a reading from a drop of blood applied to strip. Older meters require more careful preparation of the strip and leave more room for error. Newer meters perform more of the steps automatically, so there is less room for error. Newer meters typically provide the most reliable monitoring results. Sophistication — Some meters allow entry of events (like eating or exercising) and come with software programs that allow the data to be downloaded to a computer. This is most helpful for persons who test frequently and use intensive insulin treatment.
CONTINUOUS GLUCOSE TESTING — Researchers are currently evaluating continuous, less invasive, and less intrusive methods of glucose testing.
How it works — Continuous glucose monitoring systems (CGMS) use a glucose sensor (contained in a small needle) to determine the level of glucose in the interstial fluid, found between cells under the skin. The sensor wirelessly transmits results to a small recording device (the size of a pager or cell phone), which can be worn on the clothing, carried in a purse, or placed within a short distance of the sensor (eg, a bedside table). The sensor records and displays the blood glucose level every few minutes, allowing the patient to observe the trend of their blood glucose levels. The receiver can also be set to alarm if the blood glucose level is above or below a pre-set level, which can be especially helpful for patients who cannot feel when they have low blood glucose (hypoglycemia).
The sensor must be removed and reinserted in a different area every few days. Patients must continue to measure blood glucose levels with a traditional monitor several times daily to ensure that the continuous monitor is correctly calibrated.
Currently, continuous blood glucose monitors are recommended only for patients with type 1 diabetes who use intensive insulin therapy, often with an insulin pump. A combined insulin pump and continuous glucose monitor is also available.
Drawbacks — The continuous glucose sensors currently available are not as accurate as most blood glucose monitors, especially when blood glucose concentrations are rapidly rising. In one study, over 70 percent of the blood and continuous glucose values differed by 10 percent or more, and 7 percent of the readings differed by over 50 percent [5]. The CGMS tends to be less accurate in the lower glucose range (<70 mg/dL or 3.9 mmol/L) and may be inadequate for reliably detecting hypoglycemia.
Thus, continuous glucose sensing devices should not be relied upon exclusively to give patients information about blood glucose levels. Patients must continue to do several fingersticks daily to calibrate the currently available devices and to verify that the sensor readings are accurate.
In addition, the costs associated with continuous glucose monitors are much greater than those of traditional glucose monitors.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov/)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Hormone Foundation
(www.hormone.org/public/diabetes.cfm, available in English and Spanish)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Faas, A, Schellevis, FG, van Eijk, JT. The efficacy of self-monitoring of blood glucose in NIDDM subjects. Diabetes Care 1997; 20:1482.
2. Nettles, A. User error in blood glucose monitoring. Diabetes Care 1993; 16:946.
3. Self-monitoring of blood glucose. American Diabetes Association. Diabetes Care 1994; 17:81.
4. Most, RS, Gross, AM, Davidson, PC. Richardson, P. The accuracy of glucose monitoring by diabetic individuals in their home setting. Diabetes Educ 1986; 12:24.
5. Metzger, M, Leibowitz, G, Wainstein, J, et al. Reproducibility of glucose measurements using the glucose sensor. Diabetes Care 2002; 25:1185.
Foot care in diabetes
INTRODUCTION — Diabetes can lead to a number of different foot complications. Fortunately, most of these complications can be prevented with a little extra foot care. If complications do occur, daily attention will ensure that they are detected before they become serious. It may take time and effort to build good foot care habits, but self-care is essential. In fact, when it comes to foot care, the patient is a vital member of the medical team.
This topic review presents a general overview of diabetic foot complications and guidelines for good foot care. Patients should discuss foot care with their own doctor to determine the best guidelines and treatments.
DIABETES AND FOOT COMPLICATIONS — Longstanding high blood sugar can damage blood vessels, decreasing blood flow to the foot. This poor circulation can weaken the skin, contribute to the formation of ulcers, and impair wound healing. Some bacteria and fungi thrive on high levels of sugar in the bloodstream, and bacterial and fungal infections can break down the skin and complicate ulcers.
In addition, high blood sugar can damage the nerves of the foot, decreasing a patient's ability to notice pain and pressure. Without these sensations, it is easy to develop callused pressure spots and accidentally injure the skin, soft tissue, bones, and joints. Over time, bone and joint damage can dramatically alter the shape of the foot. Nerve damage can also weaken certain foot muscles, further contributing to foot deformities.
CONSEQUENCES OF FOOT COMPLICATIONS — Diabetes can lead to many different types of foot complications, including athlete's foot (a fungal infection), calluses, bunions and other foot deformities, and ulcers that can range from superficial to very deep.
More serious complications include deep skin and bone infections. Gangrene (death and decay of tissue) is a very serious complication that may include infection; widespread gangrene may require foot amputation. Approximately 5 percent of men and women with diabetes eventually require amputation of a toe or foot. This tragic consequence can be prevented in most patients by managing blood sugar levels and daily foot care.
RISK FACTORS — Patients who have had a previous foot ulcer are more likely to have future foot complications. Nerve damage, poor circulation, and chronically high blood sugar levels also increase the likelihood of foot complications.
Footwear — It is important to wear shoes that fit well. Shoes that are too tight can cause pressure ulcers. Going barefoot, even in the home, should be avoided as this increases the risk of injury to the foot.
FOOT EXAMINATION — Patients who have had type 1 diabetes for at least five years should have their feet examined at least once a year. Patients who have type 2 diabetes should have their feet examined once a year after their diagnosis.
During a foot exam, a healthcare provider checks for signs and symptoms of poor circulation, nerve damage, skin changes, and deformities. Patients should mention any problems they have noticed in their feet.
An exam may reveal decreased or absent reflexes or decreased ability to sense pressure, vibration, pin pricks, and changes in temperature.
Special devices, including a monofilament or tuning fork, can help determine the extent of nerve damage. A monofilament is a very thin, flexible thread that is used to determine if a patient can sense pressure in various areas of the foot (show figure 1). A tuning fork is used to determine if a patient can sense vibration in various areas, especially the foot and toe joints.
Possible foot problems
Poor circulation — Some simple clues can point to circulatory problems. Poor pulses, cold feet, thin or blue skin, and lack of hair signal that the feet are not getting enough blood.
Nerve damage — Nerve damage may lead to unusual sensations in the feet and legs, including pain, burning, numbness, tingling, and fatigue. Patients should describe these symptoms if they occur, including the timing, if the feet, ankles, or calves are affected, and what measures relieve the symptoms.
Nerve damage may cause no symptoms as the foot and leg slowly lose sensation and become numb. This can be very dangerous because the person may be unaware that they have improperly fit shoes, a rock or other irritant in a shoe, or other problems that could cause damage.
Skin changes — Excessive skin dryness, scaling, and cracking indicate that the circulation to this protective tissue is compromised. Other skin changes may include healed or new ulcers, calluses, and broken skin between the toes (show picture 2).
Deformities — The structure and appearance of the feet and foot joints can indicate diabetic complications. Nerve damage can lead to joint and other foot deformities. The toes may have a peculiar "claw toe" appearance, and the foot arch and other bones may appear collapsed. This destruction of the bones and joints is called Charcot arthropathy (show picture 3).
PREVENTING FOOT PROBLEMS — Controlling blood sugar levels can reduce the blood vessel and nerve damage that often lead to diabetic foot complications. If a foot wound or ulcer does occur, blood sugar control reduces the risk of requiring amputation. (See "Patient information: Self-blood glucose monitoring").
Foot care is important, although patients should also continue to follow other general guidelines for managing diabetes.
The following simple, everyday actions can reduce the chances of developing foot problems.
Quit smoking — Smoking can worsen heart and vascular problems and reduce circulation to the feet.
Avoid activities that can injure the feet — Some activities increase the risk of foot injury and are not recommended, including walking barefoot, using a heating pad or hot water bottle on the feet, and stepping into the bathtub before testing the temperature. This caution cannot be emphasized enough; foot injury is a preventable cause of foot amputation.
Use care when trimming the nails — Trim the toe nails along the shape of the toe and file the nails to remove any sharp edges (show figure 2). Never cut (or allow a manicurist to cut) the cuticles. Do not open blisters, try to free ingrown toenails, or otherwise break the skin on the feet. See a healthcare provider or podiatrist for even minor procedures.
Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat your feet dry and apply a moisturizing cream or lotion.
Check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage can be hidden. Use a mirror if it is difficult to see all parts of the feet, or ask a family member or caregiver to help.
Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break new shoes in slowly to prevent any blisters (show figure 3). Ask about customized shoes if the feet are misshapen or have already developed foot ulcers; these specialized shoes can reduce the chances of developing foot ulcers in the future. Shoe inserts may also help cushion the step and decrease pressure on the soles of the feet.
Make good foot care a habit — Good foot care in not optional. Try to follow these guidelines daily.
Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. Don't hesitate to ask the healthcare provider for a foot check at least once a year, and more frequently if there are foot changes.
TREATMENT OF FOOT PROBLEMS — The treatment of foot problems depends upon the presence and severity of foot ulcers.
Superficial ulcers involving only the top layers of skin usually includes cleaning the ulcer and removing dead skin and tissue (debridement) by a healthcare provider (show picture 1). There are a number of debridement techniques available; hydrogels may be more effective than gauze or other methods in healing foot ulcers.
If the foot is infected, antibiotics are generally prescribed. The patient (or someone in his or her household) should clean the ulcer and apply a clean dressing twice daily. The patient should keep weight off the foot ulcer as much as possible, meaning that they should not walk with the affected foot. Patients should keep the foot elevated. The ulcer should be checked by a healthcare provider at least once a week to make sure that treatment is healing the ulcer.
Ulcers that have extended into the deeper layers of the foot, involving muscle and bone, usually require hospitalization (show picture 4). More extensive laboratory testing and x-rays may be done, and intravenous antibiotics are often necessary. Surgery may be necessary to remove infected bone or to put a cast on the foot to take pressure off the ulcer.
If part of the toes or foot become severely damaged, and areas of dead tissue that have no chance of healing (gangrene) develop, partial or complete amputation may be required. This is reserved for patients who do not heal despite aggressive treatment, or whose health is threatened by the gangrene.
Some patients with severe foot ulcers and peripheral vascular disease (poor circulation) may require a procedure to restore blood flow to the foot, and potentially avoid amputation. (See "Patient information: Claudication").
NEW TREATMENTS — Several experimental approaches are being evaluated for the treatment of diabetic foot complications. New options that may help heal ulcers include synthetic wound dressings, skin grown in a laboratory, substances that stimulate healing and support the growth of infection-fighting cells, electrical stimulation, and exposure to elevated oxygen levels.
For patients with diabetes, foot complications are an ever-present risk. However, patients and their healthcare provider can design a plan for keeping the feet as healthy as possible. Patients should learn as much as possible about diabetic foot care and take an active role in medical decisions and care. While routine medical exams are certainly important, everyday foot care plays the largest role in stopping foot complications before they start.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Endocrine Society
(www.endo-society.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Ramsey, SD, Newton, K, Blough, D, et al. Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 1999; 22:382.
2. Mayfield, JA, Reiber, GE, Sanders, LJ, et al. Preventive foot care in diabetes. Diabetes Care 2004; 27 Suppl 1:S63.
3. Pham, H, Armstrong, DG, Harvey, C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care 2000; 23:606.
4. Litzelman, DK, Marriott, DJ, Vinicor, F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Diabetes Care 1997; 20:156.
This topic review presents a general overview of diabetic foot complications and guidelines for good foot care. Patients should discuss foot care with their own doctor to determine the best guidelines and treatments.
DIABETES AND FOOT COMPLICATIONS — Longstanding high blood sugar can damage blood vessels, decreasing blood flow to the foot. This poor circulation can weaken the skin, contribute to the formation of ulcers, and impair wound healing. Some bacteria and fungi thrive on high levels of sugar in the bloodstream, and bacterial and fungal infections can break down the skin and complicate ulcers.
In addition, high blood sugar can damage the nerves of the foot, decreasing a patient's ability to notice pain and pressure. Without these sensations, it is easy to develop callused pressure spots and accidentally injure the skin, soft tissue, bones, and joints. Over time, bone and joint damage can dramatically alter the shape of the foot. Nerve damage can also weaken certain foot muscles, further contributing to foot deformities.
CONSEQUENCES OF FOOT COMPLICATIONS — Diabetes can lead to many different types of foot complications, including athlete's foot (a fungal infection), calluses, bunions and other foot deformities, and ulcers that can range from superficial to very deep.
More serious complications include deep skin and bone infections. Gangrene (death and decay of tissue) is a very serious complication that may include infection; widespread gangrene may require foot amputation. Approximately 5 percent of men and women with diabetes eventually require amputation of a toe or foot. This tragic consequence can be prevented in most patients by managing blood sugar levels and daily foot care.
RISK FACTORS — Patients who have had a previous foot ulcer are more likely to have future foot complications. Nerve damage, poor circulation, and chronically high blood sugar levels also increase the likelihood of foot complications.
Footwear — It is important to wear shoes that fit well. Shoes that are too tight can cause pressure ulcers. Going barefoot, even in the home, should be avoided as this increases the risk of injury to the foot.
FOOT EXAMINATION — Patients who have had type 1 diabetes for at least five years should have their feet examined at least once a year. Patients who have type 2 diabetes should have their feet examined once a year after their diagnosis.
During a foot exam, a healthcare provider checks for signs and symptoms of poor circulation, nerve damage, skin changes, and deformities. Patients should mention any problems they have noticed in their feet.
An exam may reveal decreased or absent reflexes or decreased ability to sense pressure, vibration, pin pricks, and changes in temperature.
Special devices, including a monofilament or tuning fork, can help determine the extent of nerve damage. A monofilament is a very thin, flexible thread that is used to determine if a patient can sense pressure in various areas of the foot (show figure 1). A tuning fork is used to determine if a patient can sense vibration in various areas, especially the foot and toe joints.
Possible foot problems
Poor circulation — Some simple clues can point to circulatory problems. Poor pulses, cold feet, thin or blue skin, and lack of hair signal that the feet are not getting enough blood.
Nerve damage — Nerve damage may lead to unusual sensations in the feet and legs, including pain, burning, numbness, tingling, and fatigue. Patients should describe these symptoms if they occur, including the timing, if the feet, ankles, or calves are affected, and what measures relieve the symptoms.
Nerve damage may cause no symptoms as the foot and leg slowly lose sensation and become numb. This can be very dangerous because the person may be unaware that they have improperly fit shoes, a rock or other irritant in a shoe, or other problems that could cause damage.
Skin changes — Excessive skin dryness, scaling, and cracking indicate that the circulation to this protective tissue is compromised. Other skin changes may include healed or new ulcers, calluses, and broken skin between the toes (show picture 2).
Deformities — The structure and appearance of the feet and foot joints can indicate diabetic complications. Nerve damage can lead to joint and other foot deformities. The toes may have a peculiar "claw toe" appearance, and the foot arch and other bones may appear collapsed. This destruction of the bones and joints is called Charcot arthropathy (show picture 3).
PREVENTING FOOT PROBLEMS — Controlling blood sugar levels can reduce the blood vessel and nerve damage that often lead to diabetic foot complications. If a foot wound or ulcer does occur, blood sugar control reduces the risk of requiring amputation. (See "Patient information: Self-blood glucose monitoring").
Foot care is important, although patients should also continue to follow other general guidelines for managing diabetes.
The following simple, everyday actions can reduce the chances of developing foot problems.
Quit smoking — Smoking can worsen heart and vascular problems and reduce circulation to the feet.
Avoid activities that can injure the feet — Some activities increase the risk of foot injury and are not recommended, including walking barefoot, using a heating pad or hot water bottle on the feet, and stepping into the bathtub before testing the temperature. This caution cannot be emphasized enough; foot injury is a preventable cause of foot amputation.
Use care when trimming the nails — Trim the toe nails along the shape of the toe and file the nails to remove any sharp edges (show figure 2). Never cut (or allow a manicurist to cut) the cuticles. Do not open blisters, try to free ingrown toenails, or otherwise break the skin on the feet. See a healthcare provider or podiatrist for even minor procedures.
Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat your feet dry and apply a moisturizing cream or lotion.
Check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage can be hidden. Use a mirror if it is difficult to see all parts of the feet, or ask a family member or caregiver to help.
Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break new shoes in slowly to prevent any blisters (show figure 3). Ask about customized shoes if the feet are misshapen or have already developed foot ulcers; these specialized shoes can reduce the chances of developing foot ulcers in the future. Shoe inserts may also help cushion the step and decrease pressure on the soles of the feet.
Make good foot care a habit — Good foot care in not optional. Try to follow these guidelines daily.
Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. Don't hesitate to ask the healthcare provider for a foot check at least once a year, and more frequently if there are foot changes.
TREATMENT OF FOOT PROBLEMS — The treatment of foot problems depends upon the presence and severity of foot ulcers.
Superficial ulcers involving only the top layers of skin usually includes cleaning the ulcer and removing dead skin and tissue (debridement) by a healthcare provider (show picture 1). There are a number of debridement techniques available; hydrogels may be more effective than gauze or other methods in healing foot ulcers.
If the foot is infected, antibiotics are generally prescribed. The patient (or someone in his or her household) should clean the ulcer and apply a clean dressing twice daily. The patient should keep weight off the foot ulcer as much as possible, meaning that they should not walk with the affected foot. Patients should keep the foot elevated. The ulcer should be checked by a healthcare provider at least once a week to make sure that treatment is healing the ulcer.
Ulcers that have extended into the deeper layers of the foot, involving muscle and bone, usually require hospitalization (show picture 4). More extensive laboratory testing and x-rays may be done, and intravenous antibiotics are often necessary. Surgery may be necessary to remove infected bone or to put a cast on the foot to take pressure off the ulcer.
If part of the toes or foot become severely damaged, and areas of dead tissue that have no chance of healing (gangrene) develop, partial or complete amputation may be required. This is reserved for patients who do not heal despite aggressive treatment, or whose health is threatened by the gangrene.
Some patients with severe foot ulcers and peripheral vascular disease (poor circulation) may require a procedure to restore blood flow to the foot, and potentially avoid amputation. (See "Patient information: Claudication").
NEW TREATMENTS — Several experimental approaches are being evaluated for the treatment of diabetic foot complications. New options that may help heal ulcers include synthetic wound dressings, skin grown in a laboratory, substances that stimulate healing and support the growth of infection-fighting cells, electrical stimulation, and exposure to elevated oxygen levels.
For patients with diabetes, foot complications are an ever-present risk. However, patients and their healthcare provider can design a plan for keeping the feet as healthy as possible. Patients should learn as much as possible about diabetic foot care and take an active role in medical decisions and care. While routine medical exams are certainly important, everyday foot care plays the largest role in stopping foot complications before they start.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Endocrine Society
(www.endo-society.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Ramsey, SD, Newton, K, Blough, D, et al. Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 1999; 22:382.
2. Mayfield, JA, Reiber, GE, Sanders, LJ, et al. Preventive foot care in diabetes. Diabetes Care 2004; 27 Suppl 1:S63.
3. Pham, H, Armstrong, DG, Harvey, C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care 2000; 23:606.
4. Litzelman, DK, Marriott, DJ, Vinicor, F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Diabetes Care 1997; 20:156.
Foot care in diabetes
INTRODUCTION — Diabetes can lead to a number of different foot complications. Fortunately, most of these complications can be prevented with a little extra foot care. If complications do occur, daily attention will ensure that they are detected before they become serious. It may take time and effort to build good foot care habits, but self-care is essential. In fact, when it comes to foot care, the patient is a vital member of the medical team.
This topic review presents a general overview of diabetic foot complications and guidelines for good foot care. Patients should discuss foot care with their own doctor to determine the best guidelines and treatments.
DIABETES AND FOOT COMPLICATIONS — Longstanding high blood sugar can damage blood vessels, decreasing blood flow to the foot. This poor circulation can weaken the skin, contribute to the formation of ulcers, and impair wound healing. Some bacteria and fungi thrive on high levels of sugar in the bloodstream, and bacterial and fungal infections can break down the skin and complicate ulcers.
In addition, high blood sugar can damage the nerves of the foot, decreasing a patient's ability to notice pain and pressure. Without these sensations, it is easy to develop callused pressure spots and accidentally injure the skin, soft tissue, bones, and joints. Over time, bone and joint damage can dramatically alter the shape of the foot. Nerve damage can also weaken certain foot muscles, further contributing to foot deformities.
CONSEQUENCES OF FOOT COMPLICATIONS — Diabetes can lead to many different types of foot complications, including athlete's foot (a fungal infection), calluses, bunions and other foot deformities, and ulcers that can range from superficial to very deep.
More serious complications include deep skin and bone infections. Gangrene (death and decay of tissue) is a very serious complication that may include infection; widespread gangrene may require foot amputation. Approximately 5 percent of men and women with diabetes eventually require amputation of a toe or foot. This tragic consequence can be prevented in most patients by managing blood sugar levels and daily foot care.
RISK FACTORS — Patients who have had a previous foot ulcer are more likely to have future foot complications. Nerve damage, poor circulation, and chronically high blood sugar levels also increase the likelihood of foot complications.
Footwear — It is important to wear shoes that fit well. Shoes that are too tight can cause pressure ulcers. Going barefoot, even in the home, should be avoided as this increases the risk of injury to the foot.
FOOT EXAMINATION — Patients who have had type 1 diabetes for at least five years should have their feet examined at least once a year. Patients who have type 2 diabetes should have their feet examined once a year after their diagnosis.
During a foot exam, a healthcare provider checks for signs and symptoms of poor circulation, nerve damage, skin changes, and deformities. Patients should mention any problems they have noticed in their feet.
An exam may reveal decreased or absent reflexes or decreased ability to sense pressure, vibration, pin pricks, and changes in temperature.
Special devices, including a monofilament or tuning fork, can help determine the extent of nerve damage. A monofilament is a very thin, flexible thread that is used to determine if a patient can sense pressure in various areas of the foot (show figure 1). A tuning fork is used to determine if a patient can sense vibration in various areas, especially the foot and toe joints.
Possible foot problems
Poor circulation — Some simple clues can point to circulatory problems. Poor pulses, cold feet, thin or blue skin, and lack of hair signal that the feet are not getting enough blood.
Nerve damage — Nerve damage may lead to unusual sensations in the feet and legs, including pain, burning, numbness, tingling, and fatigue. Patients should describe these symptoms if they occur, including the timing, if the feet, ankles, or calves are affected, and what measures relieve the symptoms.
Nerve damage may cause no symptoms as the foot and leg slowly lose sensation and become numb. This can be very dangerous because the person may be unaware that they have improperly fit shoes, a rock or other irritant in a shoe, or other problems that could cause damage.
Skin changes — Excessive skin dryness, scaling, and cracking indicate that the circulation to this protective tissue is compromised. Other skin changes may include healed or new ulcers, calluses, and broken skin between the toes (show picture 2).
Deformities — The structure and appearance of the feet and foot joints can indicate diabetic complications. Nerve damage can lead to joint and other foot deformities. The toes may have a peculiar "claw toe" appearance, and the foot arch and other bones may appear collapsed. This destruction of the bones and joints is called Charcot arthropathy (show picture 3).
PREVENTING FOOT PROBLEMS — Controlling blood sugar levels can reduce the blood vessel and nerve damage that often lead to diabetic foot complications. If a foot wound or ulcer does occur, blood sugar control reduces the risk of requiring amputation. (See "Patient information: Self-blood glucose monitoring").
Foot care is important, although patients should also continue to follow other general guidelines for managing diabetes.
The following simple, everyday actions can reduce the chances of developing foot problems.
Quit smoking — Smoking can worsen heart and vascular problems and reduce circulation to the feet.
Avoid activities that can injure the feet — Some activities increase the risk of foot injury and are not recommended, including walking barefoot, using a heating pad or hot water bottle on the feet, and stepping into the bathtub before testing the temperature. This caution cannot be emphasized enough; foot injury is a preventable cause of foot amputation.
Use care when trimming the nails — Trim the toe nails along the shape of the toe and file the nails to remove any sharp edges (show figure 2). Never cut (or allow a manicurist to cut) the cuticles. Do not open blisters, try to free ingrown toenails, or otherwise break the skin on the feet. See a healthcare provider or podiatrist for even minor procedures.
Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat your feet dry and apply a moisturizing cream or lotion.
Check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage can be hidden. Use a mirror if it is difficult to see all parts of the feet, or ask a family member or caregiver to help.
Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break new shoes in slowly to prevent any blisters (show figure 3). Ask about customized shoes if the feet are misshapen or have already developed foot ulcers; these specialized shoes can reduce the chances of developing foot ulcers in the future. Shoe inserts may also help cushion the step and decrease pressure on the soles of the feet.
Make good foot care a habit — Good foot care in not optional. Try to follow these guidelines daily.
Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. Don't hesitate to ask the healthcare provider for a foot check at least once a year, and more frequently if there are foot changes.
TREATMENT OF FOOT PROBLEMS — The treatment of foot problems depends upon the presence and severity of foot ulcers.
Superficial ulcers involving only the top layers of skin usually includes cleaning the ulcer and removing dead skin and tissue (debridement) by a healthcare provider (show picture 1). There are a number of debridement techniques available; hydrogels may be more effective than gauze or other methods in healing foot ulcers.
If the foot is infected, antibiotics are generally prescribed. The patient (or someone in his or her household) should clean the ulcer and apply a clean dressing twice daily. The patient should keep weight off the foot ulcer as much as possible, meaning that they should not walk with the affected foot. Patients should keep the foot elevated. The ulcer should be checked by a healthcare provider at least once a week to make sure that treatment is healing the ulcer.
Ulcers that have extended into the deeper layers of the foot, involving muscle and bone, usually require hospitalization (show picture 4). More extensive laboratory testing and x-rays may be done, and intravenous antibiotics are often necessary. Surgery may be necessary to remove infected bone or to put a cast on the foot to take pressure off the ulcer.
If part of the toes or foot become severely damaged, and areas of dead tissue that have no chance of healing (gangrene) develop, partial or complete amputation may be required. This is reserved for patients who do not heal despite aggressive treatment, or whose health is threatened by the gangrene.
Some patients with severe foot ulcers and peripheral vascular disease (poor circulation) may require a procedure to restore blood flow to the foot, and potentially avoid amputation. (See "Patient information: Claudication").
NEW TREATMENTS — Several experimental approaches are being evaluated for the treatment of diabetic foot complications. New options that may help heal ulcers include synthetic wound dressings, skin grown in a laboratory, substances that stimulate healing and support the growth of infection-fighting cells, electrical stimulation, and exposure to elevated oxygen levels.
For patients with diabetes, foot complications are an ever-present risk. However, patients and their healthcare provider can design a plan for keeping the feet as healthy as possible. Patients should learn as much as possible about diabetic foot care and take an active role in medical decisions and care. While routine medical exams are certainly important, everyday foot care plays the largest role in stopping foot complications before they start.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Endocrine Society
(www.endo-society.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Ramsey, SD, Newton, K, Blough, D, et al. Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 1999; 22:382.
2. Mayfield, JA, Reiber, GE, Sanders, LJ, et al. Preventive foot care in diabetes. Diabetes Care 2004; 27 Suppl 1:S63.
3. Pham, H, Armstrong, DG, Harvey, C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care 2000; 23:606.
4. Litzelman, DK, Marriott, DJ, Vinicor, F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Diabetes Care 1997; 20:156.
This topic review presents a general overview of diabetic foot complications and guidelines for good foot care. Patients should discuss foot care with their own doctor to determine the best guidelines and treatments.
DIABETES AND FOOT COMPLICATIONS — Longstanding high blood sugar can damage blood vessels, decreasing blood flow to the foot. This poor circulation can weaken the skin, contribute to the formation of ulcers, and impair wound healing. Some bacteria and fungi thrive on high levels of sugar in the bloodstream, and bacterial and fungal infections can break down the skin and complicate ulcers.
In addition, high blood sugar can damage the nerves of the foot, decreasing a patient's ability to notice pain and pressure. Without these sensations, it is easy to develop callused pressure spots and accidentally injure the skin, soft tissue, bones, and joints. Over time, bone and joint damage can dramatically alter the shape of the foot. Nerve damage can also weaken certain foot muscles, further contributing to foot deformities.
CONSEQUENCES OF FOOT COMPLICATIONS — Diabetes can lead to many different types of foot complications, including athlete's foot (a fungal infection), calluses, bunions and other foot deformities, and ulcers that can range from superficial to very deep.
More serious complications include deep skin and bone infections. Gangrene (death and decay of tissue) is a very serious complication that may include infection; widespread gangrene may require foot amputation. Approximately 5 percent of men and women with diabetes eventually require amputation of a toe or foot. This tragic consequence can be prevented in most patients by managing blood sugar levels and daily foot care.
RISK FACTORS — Patients who have had a previous foot ulcer are more likely to have future foot complications. Nerve damage, poor circulation, and chronically high blood sugar levels also increase the likelihood of foot complications.
Footwear — It is important to wear shoes that fit well. Shoes that are too tight can cause pressure ulcers. Going barefoot, even in the home, should be avoided as this increases the risk of injury to the foot.
FOOT EXAMINATION — Patients who have had type 1 diabetes for at least five years should have their feet examined at least once a year. Patients who have type 2 diabetes should have their feet examined once a year after their diagnosis.
During a foot exam, a healthcare provider checks for signs and symptoms of poor circulation, nerve damage, skin changes, and deformities. Patients should mention any problems they have noticed in their feet.
An exam may reveal decreased or absent reflexes or decreased ability to sense pressure, vibration, pin pricks, and changes in temperature.
Special devices, including a monofilament or tuning fork, can help determine the extent of nerve damage. A monofilament is a very thin, flexible thread that is used to determine if a patient can sense pressure in various areas of the foot (show figure 1). A tuning fork is used to determine if a patient can sense vibration in various areas, especially the foot and toe joints.
Possible foot problems
Poor circulation — Some simple clues can point to circulatory problems. Poor pulses, cold feet, thin or blue skin, and lack of hair signal that the feet are not getting enough blood.
Nerve damage — Nerve damage may lead to unusual sensations in the feet and legs, including pain, burning, numbness, tingling, and fatigue. Patients should describe these symptoms if they occur, including the timing, if the feet, ankles, or calves are affected, and what measures relieve the symptoms.
Nerve damage may cause no symptoms as the foot and leg slowly lose sensation and become numb. This can be very dangerous because the person may be unaware that they have improperly fit shoes, a rock or other irritant in a shoe, or other problems that could cause damage.
Skin changes — Excessive skin dryness, scaling, and cracking indicate that the circulation to this protective tissue is compromised. Other skin changes may include healed or new ulcers, calluses, and broken skin between the toes (show picture 2).
Deformities — The structure and appearance of the feet and foot joints can indicate diabetic complications. Nerve damage can lead to joint and other foot deformities. The toes may have a peculiar "claw toe" appearance, and the foot arch and other bones may appear collapsed. This destruction of the bones and joints is called Charcot arthropathy (show picture 3).
PREVENTING FOOT PROBLEMS — Controlling blood sugar levels can reduce the blood vessel and nerve damage that often lead to diabetic foot complications. If a foot wound or ulcer does occur, blood sugar control reduces the risk of requiring amputation. (See "Patient information: Self-blood glucose monitoring").
Foot care is important, although patients should also continue to follow other general guidelines for managing diabetes.
The following simple, everyday actions can reduce the chances of developing foot problems.
Quit smoking — Smoking can worsen heart and vascular problems and reduce circulation to the feet.
Avoid activities that can injure the feet — Some activities increase the risk of foot injury and are not recommended, including walking barefoot, using a heating pad or hot water bottle on the feet, and stepping into the bathtub before testing the temperature. This caution cannot be emphasized enough; foot injury is a preventable cause of foot amputation.
Use care when trimming the nails — Trim the toe nails along the shape of the toe and file the nails to remove any sharp edges (show figure 2). Never cut (or allow a manicurist to cut) the cuticles. Do not open blisters, try to free ingrown toenails, or otherwise break the skin on the feet. See a healthcare provider or podiatrist for even minor procedures.
Wash and check the feet daily — Use lukewarm water and mild soap to clean the feet. Gently pat your feet dry and apply a moisturizing cream or lotion.
Check the entire surface of both feet for skin breaks, blisters, swelling, or redness, including between and underneath the toes where damage can be hidden. Use a mirror if it is difficult to see all parts of the feet, or ask a family member or caregiver to help.
Choose socks and shoes carefully — Select cotton socks that fit loosely, and change the socks every day. Select shoes that are snug but not tight, and break new shoes in slowly to prevent any blisters (show figure 3). Ask about customized shoes if the feet are misshapen or have already developed foot ulcers; these specialized shoes can reduce the chances of developing foot ulcers in the future. Shoe inserts may also help cushion the step and decrease pressure on the soles of the feet.
Make good foot care a habit — Good foot care in not optional. Try to follow these guidelines daily.
Ask for foot exams — Screening for foot complications should be a routine part of most medical visits, but is sometimes overlooked. Don't hesitate to ask the healthcare provider for a foot check at least once a year, and more frequently if there are foot changes.
TREATMENT OF FOOT PROBLEMS — The treatment of foot problems depends upon the presence and severity of foot ulcers.
Superficial ulcers involving only the top layers of skin usually includes cleaning the ulcer and removing dead skin and tissue (debridement) by a healthcare provider (show picture 1). There are a number of debridement techniques available; hydrogels may be more effective than gauze or other methods in healing foot ulcers.
If the foot is infected, antibiotics are generally prescribed. The patient (or someone in his or her household) should clean the ulcer and apply a clean dressing twice daily. The patient should keep weight off the foot ulcer as much as possible, meaning that they should not walk with the affected foot. Patients should keep the foot elevated. The ulcer should be checked by a healthcare provider at least once a week to make sure that treatment is healing the ulcer.
Ulcers that have extended into the deeper layers of the foot, involving muscle and bone, usually require hospitalization (show picture 4). More extensive laboratory testing and x-rays may be done, and intravenous antibiotics are often necessary. Surgery may be necessary to remove infected bone or to put a cast on the foot to take pressure off the ulcer.
If part of the toes or foot become severely damaged, and areas of dead tissue that have no chance of healing (gangrene) develop, partial or complete amputation may be required. This is reserved for patients who do not heal despite aggressive treatment, or whose health is threatened by the gangrene.
Some patients with severe foot ulcers and peripheral vascular disease (poor circulation) may require a procedure to restore blood flow to the foot, and potentially avoid amputation. (See "Patient information: Claudication").
NEW TREATMENTS — Several experimental approaches are being evaluated for the treatment of diabetic foot complications. New options that may help heal ulcers include synthetic wound dressings, skin grown in a laboratory, substances that stimulate healing and support the growth of infection-fighting cells, electrical stimulation, and exposure to elevated oxygen levels.
For patients with diabetes, foot complications are an ever-present risk. However, patients and their healthcare provider can design a plan for keeping the feet as healthy as possible. Patients should learn as much as possible about diabetic foot care and take an active role in medical decisions and care. While routine medical exams are certainly important, everyday foot care plays the largest role in stopping foot complications before they start.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
National Institute of Diabetes and Digestive and Kidney Diseases
(www.niddk.nih.gov)
American Diabetes Association (ADA)
(800)-DIABETES (800-342-2383)
(www.diabetes.org)
The Endocrine Society
(www.endo-society.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Ramsey, SD, Newton, K, Blough, D, et al. Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 1999; 22:382.
2. Mayfield, JA, Reiber, GE, Sanders, LJ, et al. Preventive foot care in diabetes. Diabetes Care 2004; 27 Suppl 1:S63.
3. Pham, H, Armstrong, DG, Harvey, C, et al. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care 2000; 23:606.
4. Litzelman, DK, Marriott, DJ, Vinicor, F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Diabetes Care 1997; 20:156.
HIV transmission during pregnancy
INTRODUCTION — The most common way for infants to acquire the human immunodeficiency virus (HIV) is from the mother during pregnancy, labor and delivery, and, to a lesser degree, through breastfeeding. This mother-to-child, also called perinatal, transmission of HIV resulted in the birth of approximately 1,750 HIV-infected infants in the United States each year until 1994, when it was recognized that the use of zidovudine (ZDV) could reduce transmission by nearly 70 percent. The number of AIDS cases (AIDS being the most severe manifestation of HIV infection) diagnosed among infants infected through perinatal transmission has markedly declined since 1994.
While use of medications has decreased transmission of HIV from mothers to babies, not all women are aware that they are infected with HIV. Therefore, experts strongly recommend that all pregnant women undergo screening for HIV infection and receive information, support, and counseling concerning their options. (See "Patient information: Testing for HIV").
This topic review discusses factors that can reduce perinatal HIV transmission. Many of the treatments available in the developed countries are not accessible in the rest of the world. While trials of modified therapy and other types of interventions are being performed in the developing world, they will not be reviewed here since women in the United States have other options.
CARE DURING PREGNANCY — The treatment of an HIV-infected pregnant woman usually involves an HIV specialist, primary care provider, pregnancy care provider, and the woman herself.
Initial evaluation — The initial evaluation of an HIV-infected woman who is (or is considering becoming) pregnant may include assessment of the status of her HIV disease, recommendations regarding treatments, and discussions about ways to lower the risk of mother-to-child HIV transmission. More specifically, the initial assessment often includes the following: Laboratory tests to assess the current status of HIV disease, such as blood studies to determine the viral load of HIV (quantity of RNA) and the number of CD4 or helper T cells, which are important for the individual's immune system. These numbers affect the choice of treatments and the likelihood of HIV transmission during pregnancy or delivery. Review of medications for prevention of opportunistic infections, such as Pneumocystis carinii pneumonia (PCP) or Mycobacterium avium complex (MAC). These medicines are usually given to patients with CD4 counts less than 200/µL. The medications used may depend upon the stage of pregnancy and the potentially harmful effects of certain drugs on the developing fetus. A history of any prior or current antiretroviral therapy. The drugs a patient currently receives, or has taken before, influence not only the current HIV viral load and CD4 cells, but also the degree of sensitivity of the virus to these types of drugs. In general, decisions should be based on the same criteria as for non-pregnant individuals, except that the potential impact of medications on the developing fetus are considered (see "ZDV regimen" below). Consideration of the antiretroviral medications needed for treatment of the mother's HIV infection. Combination antiretroviral therapy using three antiretroviral drugs, also called highly active antiretroviral therapy or "HAART", is currently the standard for treatment of non-pregnant individuals and for pregnant women who require treatment as well. When possible, ZDV is included as a component of maternal HAART therapy. However, if ZDV is not used during pregnancy, it is still recommended for the woman during labor and for the newborn for six weeks after birth. Consideration of the potentially harmful (teratogenic) effects of certain antiretroviral medications on the growth and development of the fetus. A teratogen is any agent, substance, or process that may interfere with proper development before birth, leading to physical abnormalities in the developing fetus. The fetus is most susceptible to potential teratogenic effects during the first 10 weeks of gestation. Discussions about the importance of appropriate support services for optimal maternal and infant health. Depending upon individual circumstances and special needs, some HIV-infected women require drug abuse treatment, mental health services, and/or other support services. Such discussions should also include long-term planning for care of the child in the event of maternal illness.
During pregnancy Blood should be drawn for CD4 cell count and viral load every three to four months to determine the need to start or change antiretroviral therapy for maternal HIV and prevention of PCP or MAC. Long-term plans should be made to ensure the women's continuity of care and ongoing adherence to appropriate antiretroviral therapies for her own health Blood tests, such as liver function testing and screening for diabetes, are recommended to detect possible complications of antiretroviral therapy. More intensive testing may be required for those receiving combination antiretroviral therapy. Routine fetal monitoring is recommended for women receiving only ZDV therapy. However, more intensive monitoring is recommended for women receiving combination antiretroviral therapy. This usually includes a level II ultrasound during the second trimester and ongoing assessment of fetal growth and development in the third trimester.
MINIMIZING TRANSMISSION RISK — There are important behavior changes that a woman can make to improve her health and reduce the risk of perinatal HIV transmission. These include discontinuing cigarette smoking, refraining from injection drug use and illegal drugs (such as cocaine or heroin), and avoiding unprotected sexual intercourse.
Labor Whenever possible, invasive procedures that might increase mother-to-child transmission of HIV should be avoided, such as fetal blood sampling, invasive fetal monitoring (eg, scalp electrodes), and artificial rupture of membranes. Because of an increased risk of HIV transmission as the time between membrane rupture ("water breaking") and delivery increases, medication may be needed to speed labor. For a woman whose cervix closed, labor can be induced with a medication applied directly to the cervix, which causes it to open (dilate). Some women, including those whose cervix has begun to dilate, will also require an intravenous medication, oxytocin, which stimulates the uterus to contract; uterine contractions further stimulate the cervix to open and thin. If induction of labor does not completely open and thin the cervix, or if complications develop that require the baby to be delivered quickly, a cesarean delivery is usually performed. Intrapartum ZDV prophylaxis should be given regardless of the mode of delivery, since the available data indicate that ZDV provides an additional protective effect against HIV transmission. Intravenous ZDV should begin three hours prior to a scheduled cesarean delivery Other antiretroviral drugs should be continued on schedule during labor or preoperatively to provide maximal protection and to minimize the risk of developing drug resistance. Episiotomy is an incision (cut) sometimes made during delivery to widen the vaginal opening. Avoiding episiotomy may decrease exposure of the infant to maternal blood. The infant should be washed before any blood is drawn, injections given, or other invasive procedures performed.
Delivery — A cesarean section is the surgical delivery of a baby by incision through the mother's abdomen and uterus. Cesarean section performed before labor begins may provide some protection against perinatal HIV transmission by decreasing or eliminating exposure to HIV-infected blood and secretions in the birth canal during delivery. It may also prevent small quantities of maternal blood from passing into the fetal circulation from the placenta during contractions, also known as "microtransfusions".
Cesarean section performed before labor decreases the likelihood of perinatal HIV transmission by about 50 percent. The combination of elective cesarean section and therapy with ZDV (ie, during pregnancy, labor, and in the newborn) reduces HIV transmission by approximately 85 percent when compared to other methods of delivery in women who have taken no antiretroviral medications. (See "Patient information: Cesarean delivery"). Summary — The American College of Obstetrics and Gynecology recommends that elective cesarean delivery be discussed and recommended for all HIV-infected pregnant women with viral loads above 1000 copies/mL. In this situation, ceserean section would be scheduled at 38 weeks of gestation. In women at very low risk for transmission, such as those with a low or undetectable viral load, the benefit of elective cesarean section may be small.
The potential benefit of elective cesarean section should be discussed with all HIV-infected pregnant women, but the final decision should be based upon a woman's individual circumstances. ZDV prophylactic therapy is recommended for both the mother and baby, regardless of the method of delivery.
Breastfeeding — Breastfeeding can clearly transmit HIV infection to the infant. In one study of over 600 mother-infant pairs from Malawi, the risk of transmitting HIV to the infant through breastmilk was 7.0 percent for infants who breastfed for one year and 10.3 percent for infants who breastfed for up to two years.
In the United States, clean water and infant formulas are readily available, and are safe alternatives to breastfeeding. Therefore, the United States Public Health Service recommends that HIV-infected mothers not breastfeed their babies. The same advice cannot be given to women in the developing world because safe alternatives to breastmilk (eg, clean water and formula) may not be consistently available.
ZDV REGIMEN — The following is the current ZDV schedule recommeded for a pregnant women during pregnancy, labor, and delivery, and for her newborn after delivery: During pregnancy, ZDV should be started anytime from the 14th week of gestation through the 34th week, and then continued for the rest of the pregnancy. The dose of ZDV is 200 mg by mouth three times a day or 300 mg twice a day. ZDV is not given during the first trimester due to theoretical concerns regarding the potentially harmful effects for the fetus. During labor and delivery, the woman is given ZDV continuously through an IV. The newborn receives ZDV syrup (2 mg/kg by mouth four times a day). The first dose should be given within the first 8 to 12 hours after birth and continued for the first six weeks of life. A lower dose is usually given to premature infants, which is gradually increased during the six weeks.
Although ZDV significantly reduces the risk of perinatal transmission, the use of one antiretroviral medication is not optimal for treatment of HIV infection. Combination antiretroviral therapy with three antiretroviral drugs, generally two nucleoside analogue reverse transcriptase inhibitors and a protease inhibitor or non-nucleoside reverse transcriptase inhibitor, is the currently recommended standard treatment for nonpregnant HIV-1-infected adults.
However, the benefit of appropriate treatment for the woman's HIV must be balanced with the potential risk of antiretroviral medications on the growth and development of the fetus. Information regarding safety during pregnancy is not available for all of these medications, and thus the "best" treatment must be chosen based upon currently available information.
There are several antiretroviral drugs that should not be used in pregnancy: these include efavirenz; the combination d4T/ddI; nevirapine in women with CD4 count >250/mm3; zalcitabine (ddC) and delavirdine.
Benefits/risks of ZDV ZDV therapy is well-tolerated in the short-term by the mother and the infant; a mild, reversible anemia (decreased number of red blood cells) may be seen in the infant during the first six weeks of life. ZDV does not appear to increase the risk of birth defects. However, further studies are necessary to draw definitive conclusions. Longer follow-up will be needed to determine if there are any long-term risks for women and children who have received ZDV. Currently, the known benefit of ZDV outweighs any theoretical risks.
Regimens during pregnancy
For women NOT taking antiretroviral therapy — Recommendations for pregnant women who are not currently taking any antiretroviral medication when pregnancy is discovered include the following: The three-part ZDV regimen is recommended for all pregnant women with HIV infection. ZDV is usually started after 14 weeks and before 34 weeks of gestation. Combining the three-part ZDV regimen with additional antiretroviral drugs (a multi-drug HAART regimen) is recommended for HIV-infected pregnant women who have HIV RNA ("viral load") levels >1,000 copies/mL. The risk of mother to child transmission is markedly decreased when HIV RNA levels are reduced to <1,000, and this is best achieved with a combination antiretroviral regimen. Women with HIV RNA levels under 1,000 may choose to take a combination HAART regimen or to take only ZDV. Women who are first seen during the first trimester may wish to delay starting antiretroviral treatment until after the first trimester. For women who have taken no antiretroviral medications during pregnancy, including ZDV, there are several regimens that can be given during labor to reduce the risk of perinatal transmission. Although these are not as effective as the full three-part ZDV regimen, they are better than no treatment.
When a woman has not taken ZDV during pregnancy, labor, or delivery, the newborn should receive a six-week course of ZDV, beginning as soon as possible after birth, preferably within 6 to 12 hours. Alternately, a combination of antiretroviral drugs may be given to the infant, depending upon the status of the mother.
For women taking antiretroviral therapy — Recommendations for these women include the following: If pregnancy is recognized after the first trimester, the current antiretroviral therapy can be continued. If pregnancy is recognized during the first trimester, the physician and patient should discuss the potential benefits and risks of continuing the treatment. If therapy is temporarily discontinued, all antiretroviral medications should be stopped at the same time and reintroduced together after the first trimester; this helps to minimize the risk of developing resistance to such drugs. If the current regimen does not currently include ZDV, it may be recommended after 14 weeks gestation. ZDV therapy is also typically recommended for the woman during labor and delivery, and for the newborn after delivery, regardless of the antiretroviral therapies used during pregnancy.
FOLLOW UP CARE
For newborns and infants — After the infant is born, monitoring for side effects of antiretroviral medications should continue. In addtion, the baby should be screened for HIV. A complete blood count prior to the administration of ZDV. This blood test measures the cellular components of the blood (white blood cells, red blood cells, and platelets). Repeat testing to measure hemoglobin (the oxygen-carrying component of the blood) following completion of the six-week ZDV regimen and at 12 weeks of age. More intensive monitoring may be required for infants who have anemia at birth, who were born prematurely (before 37 weeks gestation), or whose mothers received combination antiretroviral therapy. Infants should be screened for HIV infection at birth, two weeks, one to two months, and three to six months of age, looking for HIV DNA (the genetic material of the virus inside of lymphocytes, which are blood cells that HIV infects). Prophylaxis for PCP (eg, trimethoprim-sulfamethoxazole [Bactrim]) should be started following completion of ZDV therapy at six weeks of age because infants are at risk for acquiring this infection, even before HIV infection is diagnosed. Therapy is continued until an HIV test is negative at four months of age. If the infant is HIV-infected, this treatment should be continued.
For women after delivery — As noted above, women who only received ZDV during pregnancy need to be evaluated after delivery to determine if ongoing antiretroviral therapy is needed. In addition, ongoing comprehensive care and supportive services, including HIV-related medical care, psychosocial support, and assistance with family planning and contraception, should be offered to all women.
Long-term follow-up of children Infants and children who were exposed to antiretroviral drugs during their mother's pregnancy should receive ongoing follow-up. Data on uninfected infants exposed to ZDV are reassuring and show no abnormalities in growth, the immune system, brain function and tumor development for six years. However, data are insufficient to determine whether these children have a long-term risk for organ system abnormalities or cancer. Children exposed to antiretroviral agents should have at least a yearly physical examination, including a gynecological evaluation for older adolescent girls.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. The National Institute of Child Health and Human Development
(301) 496-5133
(www.nlm.nih.gov/medlineplus)
Centers for Disease Control and Prevention (CDC)
Phone: (404) 639-3534
Toll-free: (800) 311-3435
(www.cdc.gov)
CDC (Centers for Disease Control and Prevention) National AIDS Hotline
English: (800) 342-2437
Spanish: (800) 344-7432
CDC National Prevention Information Network (NPIN)
Toll-free: (800) 458-5231
E-mail: info@cdcnpin.org
National Institute of Allergy and Infectious Diseases (NIAID)
Phone: (301) 496-5717
(www.niaid.nih.gov)
AIDS Clinical Trials Information Service (ACTIS)
Toll-free: (800) 874-2572
E-mail: actis@actis.org
(www.actis.org)
HIV/AIDS Treatment Information Service
Toll-free: (800) 448-0440
E-mail: atis@hivatis.org
(www.hivatis.org)
[1-7]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Davis, SF, Byers, RH, Lindegren, ML, et al. Prevalence and incidence of vertically acquired HIV infection in the United States. JAMA 1995; 247:952.
2. Lyall, EG, Stainsby, C, Taylor, GP, et al. Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status. BMJ 1998; 316:268.
3. 1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. Clin Infect Dis 2000; 30 Suppl 1:S29.
4. Public Health Service Task Force recommendations for the use of antiretroviral drugs in pregnant women infected with HIV-1 for maternal health and for reducing perinatal HIV-1 transmission in the United States. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1998; 47(RR-2):1.
5. Sperling, RS, Shapiro, DE, McSherry, GD, et al. Safety of the maternal-infant zidovudine regimen utilized in Pediatric AIDS Clinical Trials Group 076 study. AIDS 1998; 12:1805.
6. The International Perinatal HIV Group. The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1: A meta-analysis of 15 prospective cohort studies. N Engl J Med 1999; 340:977.
7. United States Public Health Service recommendations for human immunodeficiency virus counseling and voluntary testing for pregnant women. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1995; 44(RR-7):1.
While use of medications has decreased transmission of HIV from mothers to babies, not all women are aware that they are infected with HIV. Therefore, experts strongly recommend that all pregnant women undergo screening for HIV infection and receive information, support, and counseling concerning their options. (See "Patient information: Testing for HIV").
This topic review discusses factors that can reduce perinatal HIV transmission. Many of the treatments available in the developed countries are not accessible in the rest of the world. While trials of modified therapy and other types of interventions are being performed in the developing world, they will not be reviewed here since women in the United States have other options.
CARE DURING PREGNANCY — The treatment of an HIV-infected pregnant woman usually involves an HIV specialist, primary care provider, pregnancy care provider, and the woman herself.
Initial evaluation — The initial evaluation of an HIV-infected woman who is (or is considering becoming) pregnant may include assessment of the status of her HIV disease, recommendations regarding treatments, and discussions about ways to lower the risk of mother-to-child HIV transmission. More specifically, the initial assessment often includes the following: Laboratory tests to assess the current status of HIV disease, such as blood studies to determine the viral load of HIV (quantity of RNA) and the number of CD4 or helper T cells, which are important for the individual's immune system. These numbers affect the choice of treatments and the likelihood of HIV transmission during pregnancy or delivery. Review of medications for prevention of opportunistic infections, such as Pneumocystis carinii pneumonia (PCP) or Mycobacterium avium complex (MAC). These medicines are usually given to patients with CD4 counts less than 200/µL. The medications used may depend upon the stage of pregnancy and the potentially harmful effects of certain drugs on the developing fetus. A history of any prior or current antiretroviral therapy. The drugs a patient currently receives, or has taken before, influence not only the current HIV viral load and CD4 cells, but also the degree of sensitivity of the virus to these types of drugs. In general, decisions should be based on the same criteria as for non-pregnant individuals, except that the potential impact of medications on the developing fetus are considered (see "ZDV regimen" below). Consideration of the antiretroviral medications needed for treatment of the mother's HIV infection. Combination antiretroviral therapy using three antiretroviral drugs, also called highly active antiretroviral therapy or "HAART", is currently the standard for treatment of non-pregnant individuals and for pregnant women who require treatment as well. When possible, ZDV is included as a component of maternal HAART therapy. However, if ZDV is not used during pregnancy, it is still recommended for the woman during labor and for the newborn for six weeks after birth. Consideration of the potentially harmful (teratogenic) effects of certain antiretroviral medications on the growth and development of the fetus. A teratogen is any agent, substance, or process that may interfere with proper development before birth, leading to physical abnormalities in the developing fetus. The fetus is most susceptible to potential teratogenic effects during the first 10 weeks of gestation. Discussions about the importance of appropriate support services for optimal maternal and infant health. Depending upon individual circumstances and special needs, some HIV-infected women require drug abuse treatment, mental health services, and/or other support services. Such discussions should also include long-term planning for care of the child in the event of maternal illness.
During pregnancy Blood should be drawn for CD4 cell count and viral load every three to four months to determine the need to start or change antiretroviral therapy for maternal HIV and prevention of PCP or MAC. Long-term plans should be made to ensure the women's continuity of care and ongoing adherence to appropriate antiretroviral therapies for her own health Blood tests, such as liver function testing and screening for diabetes, are recommended to detect possible complications of antiretroviral therapy. More intensive testing may be required for those receiving combination antiretroviral therapy. Routine fetal monitoring is recommended for women receiving only ZDV therapy. However, more intensive monitoring is recommended for women receiving combination antiretroviral therapy. This usually includes a level II ultrasound during the second trimester and ongoing assessment of fetal growth and development in the third trimester.
MINIMIZING TRANSMISSION RISK — There are important behavior changes that a woman can make to improve her health and reduce the risk of perinatal HIV transmission. These include discontinuing cigarette smoking, refraining from injection drug use and illegal drugs (such as cocaine or heroin), and avoiding unprotected sexual intercourse.
Labor Whenever possible, invasive procedures that might increase mother-to-child transmission of HIV should be avoided, such as fetal blood sampling, invasive fetal monitoring (eg, scalp electrodes), and artificial rupture of membranes. Because of an increased risk of HIV transmission as the time between membrane rupture ("water breaking") and delivery increases, medication may be needed to speed labor. For a woman whose cervix closed, labor can be induced with a medication applied directly to the cervix, which causes it to open (dilate). Some women, including those whose cervix has begun to dilate, will also require an intravenous medication, oxytocin, which stimulates the uterus to contract; uterine contractions further stimulate the cervix to open and thin. If induction of labor does not completely open and thin the cervix, or if complications develop that require the baby to be delivered quickly, a cesarean delivery is usually performed. Intrapartum ZDV prophylaxis should be given regardless of the mode of delivery, since the available data indicate that ZDV provides an additional protective effect against HIV transmission. Intravenous ZDV should begin three hours prior to a scheduled cesarean delivery Other antiretroviral drugs should be continued on schedule during labor or preoperatively to provide maximal protection and to minimize the risk of developing drug resistance. Episiotomy is an incision (cut) sometimes made during delivery to widen the vaginal opening. Avoiding episiotomy may decrease exposure of the infant to maternal blood. The infant should be washed before any blood is drawn, injections given, or other invasive procedures performed.
Delivery — A cesarean section is the surgical delivery of a baby by incision through the mother's abdomen and uterus. Cesarean section performed before labor begins may provide some protection against perinatal HIV transmission by decreasing or eliminating exposure to HIV-infected blood and secretions in the birth canal during delivery. It may also prevent small quantities of maternal blood from passing into the fetal circulation from the placenta during contractions, also known as "microtransfusions".
Cesarean section performed before labor decreases the likelihood of perinatal HIV transmission by about 50 percent. The combination of elective cesarean section and therapy with ZDV (ie, during pregnancy, labor, and in the newborn) reduces HIV transmission by approximately 85 percent when compared to other methods of delivery in women who have taken no antiretroviral medications. (See "Patient information: Cesarean delivery"). Summary — The American College of Obstetrics and Gynecology recommends that elective cesarean delivery be discussed and recommended for all HIV-infected pregnant women with viral loads above 1000 copies/mL. In this situation, ceserean section would be scheduled at 38 weeks of gestation. In women at very low risk for transmission, such as those with a low or undetectable viral load, the benefit of elective cesarean section may be small.
The potential benefit of elective cesarean section should be discussed with all HIV-infected pregnant women, but the final decision should be based upon a woman's individual circumstances. ZDV prophylactic therapy is recommended for both the mother and baby, regardless of the method of delivery.
Breastfeeding — Breastfeeding can clearly transmit HIV infection to the infant. In one study of over 600 mother-infant pairs from Malawi, the risk of transmitting HIV to the infant through breastmilk was 7.0 percent for infants who breastfed for one year and 10.3 percent for infants who breastfed for up to two years.
In the United States, clean water and infant formulas are readily available, and are safe alternatives to breastfeeding. Therefore, the United States Public Health Service recommends that HIV-infected mothers not breastfeed their babies. The same advice cannot be given to women in the developing world because safe alternatives to breastmilk (eg, clean water and formula) may not be consistently available.
ZDV REGIMEN — The following is the current ZDV schedule recommeded for a pregnant women during pregnancy, labor, and delivery, and for her newborn after delivery: During pregnancy, ZDV should be started anytime from the 14th week of gestation through the 34th week, and then continued for the rest of the pregnancy. The dose of ZDV is 200 mg by mouth three times a day or 300 mg twice a day. ZDV is not given during the first trimester due to theoretical concerns regarding the potentially harmful effects for the fetus. During labor and delivery, the woman is given ZDV continuously through an IV. The newborn receives ZDV syrup (2 mg/kg by mouth four times a day). The first dose should be given within the first 8 to 12 hours after birth and continued for the first six weeks of life. A lower dose is usually given to premature infants, which is gradually increased during the six weeks.
Although ZDV significantly reduces the risk of perinatal transmission, the use of one antiretroviral medication is not optimal for treatment of HIV infection. Combination antiretroviral therapy with three antiretroviral drugs, generally two nucleoside analogue reverse transcriptase inhibitors and a protease inhibitor or non-nucleoside reverse transcriptase inhibitor, is the currently recommended standard treatment for nonpregnant HIV-1-infected adults.
However, the benefit of appropriate treatment for the woman's HIV must be balanced with the potential risk of antiretroviral medications on the growth and development of the fetus. Information regarding safety during pregnancy is not available for all of these medications, and thus the "best" treatment must be chosen based upon currently available information.
There are several antiretroviral drugs that should not be used in pregnancy: these include efavirenz; the combination d4T/ddI; nevirapine in women with CD4 count >250/mm3; zalcitabine (ddC) and delavirdine.
Benefits/risks of ZDV ZDV therapy is well-tolerated in the short-term by the mother and the infant; a mild, reversible anemia (decreased number of red blood cells) may be seen in the infant during the first six weeks of life. ZDV does not appear to increase the risk of birth defects. However, further studies are necessary to draw definitive conclusions. Longer follow-up will be needed to determine if there are any long-term risks for women and children who have received ZDV. Currently, the known benefit of ZDV outweighs any theoretical risks.
Regimens during pregnancy
For women NOT taking antiretroviral therapy — Recommendations for pregnant women who are not currently taking any antiretroviral medication when pregnancy is discovered include the following: The three-part ZDV regimen is recommended for all pregnant women with HIV infection. ZDV is usually started after 14 weeks and before 34 weeks of gestation. Combining the three-part ZDV regimen with additional antiretroviral drugs (a multi-drug HAART regimen) is recommended for HIV-infected pregnant women who have HIV RNA ("viral load") levels >1,000 copies/mL. The risk of mother to child transmission is markedly decreased when HIV RNA levels are reduced to <1,000, and this is best achieved with a combination antiretroviral regimen. Women with HIV RNA levels under 1,000 may choose to take a combination HAART regimen or to take only ZDV. Women who are first seen during the first trimester may wish to delay starting antiretroviral treatment until after the first trimester. For women who have taken no antiretroviral medications during pregnancy, including ZDV, there are several regimens that can be given during labor to reduce the risk of perinatal transmission. Although these are not as effective as the full three-part ZDV regimen, they are better than no treatment.
When a woman has not taken ZDV during pregnancy, labor, or delivery, the newborn should receive a six-week course of ZDV, beginning as soon as possible after birth, preferably within 6 to 12 hours. Alternately, a combination of antiretroviral drugs may be given to the infant, depending upon the status of the mother.
For women taking antiretroviral therapy — Recommendations for these women include the following: If pregnancy is recognized after the first trimester, the current antiretroviral therapy can be continued. If pregnancy is recognized during the first trimester, the physician and patient should discuss the potential benefits and risks of continuing the treatment. If therapy is temporarily discontinued, all antiretroviral medications should be stopped at the same time and reintroduced together after the first trimester; this helps to minimize the risk of developing resistance to such drugs. If the current regimen does not currently include ZDV, it may be recommended after 14 weeks gestation. ZDV therapy is also typically recommended for the woman during labor and delivery, and for the newborn after delivery, regardless of the antiretroviral therapies used during pregnancy.
FOLLOW UP CARE
For newborns and infants — After the infant is born, monitoring for side effects of antiretroviral medications should continue. In addtion, the baby should be screened for HIV. A complete blood count prior to the administration of ZDV. This blood test measures the cellular components of the blood (white blood cells, red blood cells, and platelets). Repeat testing to measure hemoglobin (the oxygen-carrying component of the blood) following completion of the six-week ZDV regimen and at 12 weeks of age. More intensive monitoring may be required for infants who have anemia at birth, who were born prematurely (before 37 weeks gestation), or whose mothers received combination antiretroviral therapy. Infants should be screened for HIV infection at birth, two weeks, one to two months, and three to six months of age, looking for HIV DNA (the genetic material of the virus inside of lymphocytes, which are blood cells that HIV infects). Prophylaxis for PCP (eg, trimethoprim-sulfamethoxazole [Bactrim]) should be started following completion of ZDV therapy at six weeks of age because infants are at risk for acquiring this infection, even before HIV infection is diagnosed. Therapy is continued until an HIV test is negative at four months of age. If the infant is HIV-infected, this treatment should be continued.
For women after delivery — As noted above, women who only received ZDV during pregnancy need to be evaluated after delivery to determine if ongoing antiretroviral therapy is needed. In addition, ongoing comprehensive care and supportive services, including HIV-related medical care, psychosocial support, and assistance with family planning and contraception, should be offered to all women.
Long-term follow-up of children Infants and children who were exposed to antiretroviral drugs during their mother's pregnancy should receive ongoing follow-up. Data on uninfected infants exposed to ZDV are reassuring and show no abnormalities in growth, the immune system, brain function and tumor development for six years. However, data are insufficient to determine whether these children have a long-term risk for organ system abnormalities or cancer. Children exposed to antiretroviral agents should have at least a yearly physical examination, including a gynecological evaluation for older adolescent girls.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. The National Institute of Child Health and Human Development
(301) 496-5133
(www.nlm.nih.gov/medlineplus)
Centers for Disease Control and Prevention (CDC)
Phone: (404) 639-3534
Toll-free: (800) 311-3435
(www.cdc.gov)
CDC (Centers for Disease Control and Prevention) National AIDS Hotline
English: (800) 342-2437
Spanish: (800) 344-7432
CDC National Prevention Information Network (NPIN)
Toll-free: (800) 458-5231
E-mail: info@cdcnpin.org
National Institute of Allergy and Infectious Diseases (NIAID)
Phone: (301) 496-5717
(www.niaid.nih.gov)
AIDS Clinical Trials Information Service (ACTIS)
Toll-free: (800) 874-2572
E-mail: actis@actis.org
(www.actis.org)
HIV/AIDS Treatment Information Service
Toll-free: (800) 448-0440
E-mail: atis@hivatis.org
(www.hivatis.org)
[1-7]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Davis, SF, Byers, RH, Lindegren, ML, et al. Prevalence and incidence of vertically acquired HIV infection in the United States. JAMA 1995; 247:952.
2. Lyall, EG, Stainsby, C, Taylor, GP, et al. Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status. BMJ 1998; 316:268.
3. 1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. Clin Infect Dis 2000; 30 Suppl 1:S29.
4. Public Health Service Task Force recommendations for the use of antiretroviral drugs in pregnant women infected with HIV-1 for maternal health and for reducing perinatal HIV-1 transmission in the United States. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1998; 47(RR-2):1.
5. Sperling, RS, Shapiro, DE, McSherry, GD, et al. Safety of the maternal-infant zidovudine regimen utilized in Pediatric AIDS Clinical Trials Group 076 study. AIDS 1998; 12:1805.
6. The International Perinatal HIV Group. The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1: A meta-analysis of 15 prospective cohort studies. N Engl J Med 1999; 340:977.
7. United States Public Health Service recommendations for human immunodeficiency virus counseling and voluntary testing for pregnant women. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1995; 44(RR-7):1.
HIV transmission during pregnancy
INTRODUCTION — The most common way for infants to acquire the human immunodeficiency virus (HIV) is from the mother during pregnancy, labor and delivery, and, to a lesser degree, through breastfeeding. This mother-to-child, also called perinatal, transmission of HIV resulted in the birth of approximately 1,750 HIV-infected infants in the United States each year until 1994, when it was recognized that the use of zidovudine (ZDV) could reduce transmission by nearly 70 percent. The number of AIDS cases (AIDS being the most severe manifestation of HIV infection) diagnosed among infants infected through perinatal transmission has markedly declined since 1994.
While use of medications has decreased transmission of HIV from mothers to babies, not all women are aware that they are infected with HIV. Therefore, experts strongly recommend that all pregnant women undergo screening for HIV infection and receive information, support, and counseling concerning their options. (See "Patient information: Testing for HIV").
This topic review discusses factors that can reduce perinatal HIV transmission. Many of the treatments available in the developed countries are not accessible in the rest of the world. While trials of modified therapy and other types of interventions are being performed in the developing world, they will not be reviewed here since women in the United States have other options.
CARE DURING PREGNANCY — The treatment of an HIV-infected pregnant woman usually involves an HIV specialist, primary care provider, pregnancy care provider, and the woman herself.
Initial evaluation — The initial evaluation of an HIV-infected woman who is (or is considering becoming) pregnant may include assessment of the status of her HIV disease, recommendations regarding treatments, and discussions about ways to lower the risk of mother-to-child HIV transmission. More specifically, the initial assessment often includes the following: Laboratory tests to assess the current status of HIV disease, such as blood studies to determine the viral load of HIV (quantity of RNA) and the number of CD4 or helper T cells, which are important for the individual's immune system. These numbers affect the choice of treatments and the likelihood of HIV transmission during pregnancy or delivery. Review of medications for prevention of opportunistic infections, such as Pneumocystis carinii pneumonia (PCP) or Mycobacterium avium complex (MAC). These medicines are usually given to patients with CD4 counts less than 200/µL. The medications used may depend upon the stage of pregnancy and the potentially harmful effects of certain drugs on the developing fetus. A history of any prior or current antiretroviral therapy. The drugs a patient currently receives, or has taken before, influence not only the current HIV viral load and CD4 cells, but also the degree of sensitivity of the virus to these types of drugs. In general, decisions should be based on the same criteria as for non-pregnant individuals, except that the potential impact of medications on the developing fetus are considered (see "ZDV regimen" below). Consideration of the antiretroviral medications needed for treatment of the mother's HIV infection. Combination antiretroviral therapy using three antiretroviral drugs, also called highly active antiretroviral therapy or "HAART", is currently the standard for treatment of non-pregnant individuals and for pregnant women who require treatment as well. When possible, ZDV is included as a component of maternal HAART therapy. However, if ZDV is not used during pregnancy, it is still recommended for the woman during labor and for the newborn for six weeks after birth. Consideration of the potentially harmful (teratogenic) effects of certain antiretroviral medications on the growth and development of the fetus. A teratogen is any agent, substance, or process that may interfere with proper development before birth, leading to physical abnormalities in the developing fetus. The fetus is most susceptible to potential teratogenic effects during the first 10 weeks of gestation. Discussions about the importance of appropriate support services for optimal maternal and infant health. Depending upon individual circumstances and special needs, some HIV-infected women require drug abuse treatment, mental health services, and/or other support services. Such discussions should also include long-term planning for care of the child in the event of maternal illness.
During pregnancy Blood should be drawn for CD4 cell count and viral load every three to four months to determine the need to start or change antiretroviral therapy for maternal HIV and prevention of PCP or MAC. Long-term plans should be made to ensure the women's continuity of care and ongoing adherence to appropriate antiretroviral therapies for her own health Blood tests, such as liver function testing and screening for diabetes, are recommended to detect possible complications of antiretroviral therapy. More intensive testing may be required for those receiving combination antiretroviral therapy. Routine fetal monitoring is recommended for women receiving only ZDV therapy. However, more intensive monitoring is recommended for women receiving combination antiretroviral therapy. This usually includes a level II ultrasound during the second trimester and ongoing assessment of fetal growth and development in the third trimester.
MINIMIZING TRANSMISSION RISK — There are important behavior changes that a woman can make to improve her health and reduce the risk of perinatal HIV transmission. These include discontinuing cigarette smoking, refraining from injection drug use and illegal drugs (such as cocaine or heroin), and avoiding unprotected sexual intercourse.
Labor Whenever possible, invasive procedures that might increase mother-to-child transmission of HIV should be avoided, such as fetal blood sampling, invasive fetal monitoring (eg, scalp electrodes), and artificial rupture of membranes. Because of an increased risk of HIV transmission as the time between membrane rupture ("water breaking") and delivery increases, medication may be needed to speed labor. For a woman whose cervix closed, labor can be induced with a medication applied directly to the cervix, which causes it to open (dilate). Some women, including those whose cervix has begun to dilate, will also require an intravenous medication, oxytocin, which stimulates the uterus to contract; uterine contractions further stimulate the cervix to open and thin. If induction of labor does not completely open and thin the cervix, or if complications develop that require the baby to be delivered quickly, a cesarean delivery is usually performed. Intrapartum ZDV prophylaxis should be given regardless of the mode of delivery, since the available data indicate that ZDV provides an additional protective effect against HIV transmission. Intravenous ZDV should begin three hours prior to a scheduled cesarean delivery Other antiretroviral drugs should be continued on schedule during labor or preoperatively to provide maximal protection and to minimize the risk of developing drug resistance. Episiotomy is an incision (cut) sometimes made during delivery to widen the vaginal opening. Avoiding episiotomy may decrease exposure of the infant to maternal blood. The infant should be washed before any blood is drawn, injections given, or other invasive procedures performed.
Delivery — A cesarean section is the surgical delivery of a baby by incision through the mother's abdomen and uterus. Cesarean section performed before labor begins may provide some protection against perinatal HIV transmission by decreasing or eliminating exposure to HIV-infected blood and secretions in the birth canal during delivery. It may also prevent small quantities of maternal blood from passing into the fetal circulation from the placenta during contractions, also known as "microtransfusions".
Cesarean section performed before labor decreases the likelihood of perinatal HIV transmission by about 50 percent. The combination of elective cesarean section and therapy with ZDV (ie, during pregnancy, labor, and in the newborn) reduces HIV transmission by approximately 85 percent when compared to other methods of delivery in women who have taken no antiretroviral medications. (See "Patient information: Cesarean delivery"). Summary — The American College of Obstetrics and Gynecology recommends that elective cesarean delivery be discussed and recommended for all HIV-infected pregnant women with viral loads above 1000 copies/mL. In this situation, ceserean section would be scheduled at 38 weeks of gestation. In women at very low risk for transmission, such as those with a low or undetectable viral load, the benefit of elective cesarean section may be small.
The potential benefit of elective cesarean section should be discussed with all HIV-infected pregnant women, but the final decision should be based upon a woman's individual circumstances. ZDV prophylactic therapy is recommended for both the mother and baby, regardless of the method of delivery.
Breastfeeding — Breastfeeding can clearly transmit HIV infection to the infant. In one study of over 600 mother-infant pairs from Malawi, the risk of transmitting HIV to the infant through breastmilk was 7.0 percent for infants who breastfed for one year and 10.3 percent for infants who breastfed for up to two years.
In the United States, clean water and infant formulas are readily available, and are safe alternatives to breastfeeding. Therefore, the United States Public Health Service recommends that HIV-infected mothers not breastfeed their babies. The same advice cannot be given to women in the developing world because safe alternatives to breastmilk (eg, clean water and formula) may not be consistently available.
ZDV REGIMEN — The following is the current ZDV schedule recommeded for a pregnant women during pregnancy, labor, and delivery, and for her newborn after delivery: During pregnancy, ZDV should be started anytime from the 14th week of gestation through the 34th week, and then continued for the rest of the pregnancy. The dose of ZDV is 200 mg by mouth three times a day or 300 mg twice a day. ZDV is not given during the first trimester due to theoretical concerns regarding the potentially harmful effects for the fetus. During labor and delivery, the woman is given ZDV continuously through an IV. The newborn receives ZDV syrup (2 mg/kg by mouth four times a day). The first dose should be given within the first 8 to 12 hours after birth and continued for the first six weeks of life. A lower dose is usually given to premature infants, which is gradually increased during the six weeks.
Although ZDV significantly reduces the risk of perinatal transmission, the use of one antiretroviral medication is not optimal for treatment of HIV infection. Combination antiretroviral therapy with three antiretroviral drugs, generally two nucleoside analogue reverse transcriptase inhibitors and a protease inhibitor or non-nucleoside reverse transcriptase inhibitor, is the currently recommended standard treatment for nonpregnant HIV-1-infected adults.
However, the benefit of appropriate treatment for the woman's HIV must be balanced with the potential risk of antiretroviral medications on the growth and development of the fetus. Information regarding safety during pregnancy is not available for all of these medications, and thus the "best" treatment must be chosen based upon currently available information.
There are several antiretroviral drugs that should not be used in pregnancy: these include efavirenz; the combination d4T/ddI; nevirapine in women with CD4 count >250/mm3; zalcitabine (ddC) and delavirdine.
Benefits/risks of ZDV ZDV therapy is well-tolerated in the short-term by the mother and the infant; a mild, reversible anemia (decreased number of red blood cells) may be seen in the infant during the first six weeks of life. ZDV does not appear to increase the risk of birth defects. However, further studies are necessary to draw definitive conclusions. Longer follow-up will be needed to determine if there are any long-term risks for women and children who have received ZDV. Currently, the known benefit of ZDV outweighs any theoretical risks.
Regimens during pregnancy
For women NOT taking antiretroviral therapy — Recommendations for pregnant women who are not currently taking any antiretroviral medication when pregnancy is discovered include the following: The three-part ZDV regimen is recommended for all pregnant women with HIV infection. ZDV is usually started after 14 weeks and before 34 weeks of gestation. Combining the three-part ZDV regimen with additional antiretroviral drugs (a multi-drug HAART regimen) is recommended for HIV-infected pregnant women who have HIV RNA ("viral load") levels >1,000 copies/mL. The risk of mother to child transmission is markedly decreased when HIV RNA levels are reduced to <1,000, and this is best achieved with a combination antiretroviral regimen. Women with HIV RNA levels under 1,000 may choose to take a combination HAART regimen or to take only ZDV. Women who are first seen during the first trimester may wish to delay starting antiretroviral treatment until after the first trimester. For women who have taken no antiretroviral medications during pregnancy, including ZDV, there are several regimens that can be given during labor to reduce the risk of perinatal transmission. Although these are not as effective as the full three-part ZDV regimen, they are better than no treatment.
When a woman has not taken ZDV during pregnancy, labor, or delivery, the newborn should receive a six-week course of ZDV, beginning as soon as possible after birth, preferably within 6 to 12 hours. Alternately, a combination of antiretroviral drugs may be given to the infant, depending upon the status of the mother.
For women taking antiretroviral therapy — Recommendations for these women include the following: If pregnancy is recognized after the first trimester, the current antiretroviral therapy can be continued. If pregnancy is recognized during the first trimester, the physician and patient should discuss the potential benefits and risks of continuing the treatment. If therapy is temporarily discontinued, all antiretroviral medications should be stopped at the same time and reintroduced together after the first trimester; this helps to minimize the risk of developing resistance to such drugs. If the current regimen does not currently include ZDV, it may be recommended after 14 weeks gestation. ZDV therapy is also typically recommended for the woman during labor and delivery, and for the newborn after delivery, regardless of the antiretroviral therapies used during pregnancy.
FOLLOW UP CARE
For newborns and infants — After the infant is born, monitoring for side effects of antiretroviral medications should continue. In addtion, the baby should be screened for HIV. A complete blood count prior to the administration of ZDV. This blood test measures the cellular components of the blood (white blood cells, red blood cells, and platelets). Repeat testing to measure hemoglobin (the oxygen-carrying component of the blood) following completion of the six-week ZDV regimen and at 12 weeks of age. More intensive monitoring may be required for infants who have anemia at birth, who were born prematurely (before 37 weeks gestation), or whose mothers received combination antiretroviral therapy. Infants should be screened for HIV infection at birth, two weeks, one to two months, and three to six months of age, looking for HIV DNA (the genetic material of the virus inside of lymphocytes, which are blood cells that HIV infects). Prophylaxis for PCP (eg, trimethoprim-sulfamethoxazole [Bactrim]) should be started following completion of ZDV therapy at six weeks of age because infants are at risk for acquiring this infection, even before HIV infection is diagnosed. Therapy is continued until an HIV test is negative at four months of age. If the infant is HIV-infected, this treatment should be continued.
For women after delivery — As noted above, women who only received ZDV during pregnancy need to be evaluated after delivery to determine if ongoing antiretroviral therapy is needed. In addition, ongoing comprehensive care and supportive services, including HIV-related medical care, psychosocial support, and assistance with family planning and contraception, should be offered to all women.
Long-term follow-up of children Infants and children who were exposed to antiretroviral drugs during their mother's pregnancy should receive ongoing follow-up. Data on uninfected infants exposed to ZDV are reassuring and show no abnormalities in growth, the immune system, brain function and tumor development for six years. However, data are insufficient to determine whether these children have a long-term risk for organ system abnormalities or cancer. Children exposed to antiretroviral agents should have at least a yearly physical examination, including a gynecological evaluation for older adolescent girls.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. The National Institute of Child Health and Human Development
(301) 496-5133
(www.nlm.nih.gov/medlineplus)
Centers for Disease Control and Prevention (CDC)
Phone: (404) 639-3534
Toll-free: (800) 311-3435
(www.cdc.gov)
CDC (Centers for Disease Control and Prevention) National AIDS Hotline
English: (800) 342-2437
Spanish: (800) 344-7432
CDC National Prevention Information Network (NPIN)
Toll-free: (800) 458-5231
E-mail: info@cdcnpin.org
National Institute of Allergy and Infectious Diseases (NIAID)
Phone: (301) 496-5717
(www.niaid.nih.gov)
AIDS Clinical Trials Information Service (ACTIS)
Toll-free: (800) 874-2572
E-mail: actis@actis.org
(www.actis.org)
HIV/AIDS Treatment Information Service
Toll-free: (800) 448-0440
E-mail: atis@hivatis.org
(www.hivatis.org)
[1-7]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Davis, SF, Byers, RH, Lindegren, ML, et al. Prevalence and incidence of vertically acquired HIV infection in the United States. JAMA 1995; 247:952.
2. Lyall, EG, Stainsby, C, Taylor, GP, et al. Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status. BMJ 1998; 316:268.
3. 1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. Clin Infect Dis 2000; 30 Suppl 1:S29.
4. Public Health Service Task Force recommendations for the use of antiretroviral drugs in pregnant women infected with HIV-1 for maternal health and for reducing perinatal HIV-1 transmission in the United States. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1998; 47(RR-2):1.
5. Sperling, RS, Shapiro, DE, McSherry, GD, et al. Safety of the maternal-infant zidovudine regimen utilized in Pediatric AIDS Clinical Trials Group 076 study. AIDS 1998; 12:1805.
6. The International Perinatal HIV Group. The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1: A meta-analysis of 15 prospective cohort studies. N Engl J Med 1999; 340:977.
7. United States Public Health Service recommendations for human immunodeficiency virus counseling and voluntary testing for pregnant women. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1995; 44(RR-7):1.
While use of medications has decreased transmission of HIV from mothers to babies, not all women are aware that they are infected with HIV. Therefore, experts strongly recommend that all pregnant women undergo screening for HIV infection and receive information, support, and counseling concerning their options. (See "Patient information: Testing for HIV").
This topic review discusses factors that can reduce perinatal HIV transmission. Many of the treatments available in the developed countries are not accessible in the rest of the world. While trials of modified therapy and other types of interventions are being performed in the developing world, they will not be reviewed here since women in the United States have other options.
CARE DURING PREGNANCY — The treatment of an HIV-infected pregnant woman usually involves an HIV specialist, primary care provider, pregnancy care provider, and the woman herself.
Initial evaluation — The initial evaluation of an HIV-infected woman who is (or is considering becoming) pregnant may include assessment of the status of her HIV disease, recommendations regarding treatments, and discussions about ways to lower the risk of mother-to-child HIV transmission. More specifically, the initial assessment often includes the following: Laboratory tests to assess the current status of HIV disease, such as blood studies to determine the viral load of HIV (quantity of RNA) and the number of CD4 or helper T cells, which are important for the individual's immune system. These numbers affect the choice of treatments and the likelihood of HIV transmission during pregnancy or delivery. Review of medications for prevention of opportunistic infections, such as Pneumocystis carinii pneumonia (PCP) or Mycobacterium avium complex (MAC). These medicines are usually given to patients with CD4 counts less than 200/µL. The medications used may depend upon the stage of pregnancy and the potentially harmful effects of certain drugs on the developing fetus. A history of any prior or current antiretroviral therapy. The drugs a patient currently receives, or has taken before, influence not only the current HIV viral load and CD4 cells, but also the degree of sensitivity of the virus to these types of drugs. In general, decisions should be based on the same criteria as for non-pregnant individuals, except that the potential impact of medications on the developing fetus are considered (see "ZDV regimen" below). Consideration of the antiretroviral medications needed for treatment of the mother's HIV infection. Combination antiretroviral therapy using three antiretroviral drugs, also called highly active antiretroviral therapy or "HAART", is currently the standard for treatment of non-pregnant individuals and for pregnant women who require treatment as well. When possible, ZDV is included as a component of maternal HAART therapy. However, if ZDV is not used during pregnancy, it is still recommended for the woman during labor and for the newborn for six weeks after birth. Consideration of the potentially harmful (teratogenic) effects of certain antiretroviral medications on the growth and development of the fetus. A teratogen is any agent, substance, or process that may interfere with proper development before birth, leading to physical abnormalities in the developing fetus. The fetus is most susceptible to potential teratogenic effects during the first 10 weeks of gestation. Discussions about the importance of appropriate support services for optimal maternal and infant health. Depending upon individual circumstances and special needs, some HIV-infected women require drug abuse treatment, mental health services, and/or other support services. Such discussions should also include long-term planning for care of the child in the event of maternal illness.
During pregnancy Blood should be drawn for CD4 cell count and viral load every three to four months to determine the need to start or change antiretroviral therapy for maternal HIV and prevention of PCP or MAC. Long-term plans should be made to ensure the women's continuity of care and ongoing adherence to appropriate antiretroviral therapies for her own health Blood tests, such as liver function testing and screening for diabetes, are recommended to detect possible complications of antiretroviral therapy. More intensive testing may be required for those receiving combination antiretroviral therapy. Routine fetal monitoring is recommended for women receiving only ZDV therapy. However, more intensive monitoring is recommended for women receiving combination antiretroviral therapy. This usually includes a level II ultrasound during the second trimester and ongoing assessment of fetal growth and development in the third trimester.
MINIMIZING TRANSMISSION RISK — There are important behavior changes that a woman can make to improve her health and reduce the risk of perinatal HIV transmission. These include discontinuing cigarette smoking, refraining from injection drug use and illegal drugs (such as cocaine or heroin), and avoiding unprotected sexual intercourse.
Labor Whenever possible, invasive procedures that might increase mother-to-child transmission of HIV should be avoided, such as fetal blood sampling, invasive fetal monitoring (eg, scalp electrodes), and artificial rupture of membranes. Because of an increased risk of HIV transmission as the time between membrane rupture ("water breaking") and delivery increases, medication may be needed to speed labor. For a woman whose cervix closed, labor can be induced with a medication applied directly to the cervix, which causes it to open (dilate). Some women, including those whose cervix has begun to dilate, will also require an intravenous medication, oxytocin, which stimulates the uterus to contract; uterine contractions further stimulate the cervix to open and thin. If induction of labor does not completely open and thin the cervix, or if complications develop that require the baby to be delivered quickly, a cesarean delivery is usually performed. Intrapartum ZDV prophylaxis should be given regardless of the mode of delivery, since the available data indicate that ZDV provides an additional protective effect against HIV transmission. Intravenous ZDV should begin three hours prior to a scheduled cesarean delivery Other antiretroviral drugs should be continued on schedule during labor or preoperatively to provide maximal protection and to minimize the risk of developing drug resistance. Episiotomy is an incision (cut) sometimes made during delivery to widen the vaginal opening. Avoiding episiotomy may decrease exposure of the infant to maternal blood. The infant should be washed before any blood is drawn, injections given, or other invasive procedures performed.
Delivery — A cesarean section is the surgical delivery of a baby by incision through the mother's abdomen and uterus. Cesarean section performed before labor begins may provide some protection against perinatal HIV transmission by decreasing or eliminating exposure to HIV-infected blood and secretions in the birth canal during delivery. It may also prevent small quantities of maternal blood from passing into the fetal circulation from the placenta during contractions, also known as "microtransfusions".
Cesarean section performed before labor decreases the likelihood of perinatal HIV transmission by about 50 percent. The combination of elective cesarean section and therapy with ZDV (ie, during pregnancy, labor, and in the newborn) reduces HIV transmission by approximately 85 percent when compared to other methods of delivery in women who have taken no antiretroviral medications. (See "Patient information: Cesarean delivery"). Summary — The American College of Obstetrics and Gynecology recommends that elective cesarean delivery be discussed and recommended for all HIV-infected pregnant women with viral loads above 1000 copies/mL. In this situation, ceserean section would be scheduled at 38 weeks of gestation. In women at very low risk for transmission, such as those with a low or undetectable viral load, the benefit of elective cesarean section may be small.
The potential benefit of elective cesarean section should be discussed with all HIV-infected pregnant women, but the final decision should be based upon a woman's individual circumstances. ZDV prophylactic therapy is recommended for both the mother and baby, regardless of the method of delivery.
Breastfeeding — Breastfeeding can clearly transmit HIV infection to the infant. In one study of over 600 mother-infant pairs from Malawi, the risk of transmitting HIV to the infant through breastmilk was 7.0 percent for infants who breastfed for one year and 10.3 percent for infants who breastfed for up to two years.
In the United States, clean water and infant formulas are readily available, and are safe alternatives to breastfeeding. Therefore, the United States Public Health Service recommends that HIV-infected mothers not breastfeed their babies. The same advice cannot be given to women in the developing world because safe alternatives to breastmilk (eg, clean water and formula) may not be consistently available.
ZDV REGIMEN — The following is the current ZDV schedule recommeded for a pregnant women during pregnancy, labor, and delivery, and for her newborn after delivery: During pregnancy, ZDV should be started anytime from the 14th week of gestation through the 34th week, and then continued for the rest of the pregnancy. The dose of ZDV is 200 mg by mouth three times a day or 300 mg twice a day. ZDV is not given during the first trimester due to theoretical concerns regarding the potentially harmful effects for the fetus. During labor and delivery, the woman is given ZDV continuously through an IV. The newborn receives ZDV syrup (2 mg/kg by mouth four times a day). The first dose should be given within the first 8 to 12 hours after birth and continued for the first six weeks of life. A lower dose is usually given to premature infants, which is gradually increased during the six weeks.
Although ZDV significantly reduces the risk of perinatal transmission, the use of one antiretroviral medication is not optimal for treatment of HIV infection. Combination antiretroviral therapy with three antiretroviral drugs, generally two nucleoside analogue reverse transcriptase inhibitors and a protease inhibitor or non-nucleoside reverse transcriptase inhibitor, is the currently recommended standard treatment for nonpregnant HIV-1-infected adults.
However, the benefit of appropriate treatment for the woman's HIV must be balanced with the potential risk of antiretroviral medications on the growth and development of the fetus. Information regarding safety during pregnancy is not available for all of these medications, and thus the "best" treatment must be chosen based upon currently available information.
There are several antiretroviral drugs that should not be used in pregnancy: these include efavirenz; the combination d4T/ddI; nevirapine in women with CD4 count >250/mm3; zalcitabine (ddC) and delavirdine.
Benefits/risks of ZDV ZDV therapy is well-tolerated in the short-term by the mother and the infant; a mild, reversible anemia (decreased number of red blood cells) may be seen in the infant during the first six weeks of life. ZDV does not appear to increase the risk of birth defects. However, further studies are necessary to draw definitive conclusions. Longer follow-up will be needed to determine if there are any long-term risks for women and children who have received ZDV. Currently, the known benefit of ZDV outweighs any theoretical risks.
Regimens during pregnancy
For women NOT taking antiretroviral therapy — Recommendations for pregnant women who are not currently taking any antiretroviral medication when pregnancy is discovered include the following: The three-part ZDV regimen is recommended for all pregnant women with HIV infection. ZDV is usually started after 14 weeks and before 34 weeks of gestation. Combining the three-part ZDV regimen with additional antiretroviral drugs (a multi-drug HAART regimen) is recommended for HIV-infected pregnant women who have HIV RNA ("viral load") levels >1,000 copies/mL. The risk of mother to child transmission is markedly decreased when HIV RNA levels are reduced to <1,000, and this is best achieved with a combination antiretroviral regimen. Women with HIV RNA levels under 1,000 may choose to take a combination HAART regimen or to take only ZDV. Women who are first seen during the first trimester may wish to delay starting antiretroviral treatment until after the first trimester. For women who have taken no antiretroviral medications during pregnancy, including ZDV, there are several regimens that can be given during labor to reduce the risk of perinatal transmission. Although these are not as effective as the full three-part ZDV regimen, they are better than no treatment.
When a woman has not taken ZDV during pregnancy, labor, or delivery, the newborn should receive a six-week course of ZDV, beginning as soon as possible after birth, preferably within 6 to 12 hours. Alternately, a combination of antiretroviral drugs may be given to the infant, depending upon the status of the mother.
For women taking antiretroviral therapy — Recommendations for these women include the following: If pregnancy is recognized after the first trimester, the current antiretroviral therapy can be continued. If pregnancy is recognized during the first trimester, the physician and patient should discuss the potential benefits and risks of continuing the treatment. If therapy is temporarily discontinued, all antiretroviral medications should be stopped at the same time and reintroduced together after the first trimester; this helps to minimize the risk of developing resistance to such drugs. If the current regimen does not currently include ZDV, it may be recommended after 14 weeks gestation. ZDV therapy is also typically recommended for the woman during labor and delivery, and for the newborn after delivery, regardless of the antiretroviral therapies used during pregnancy.
FOLLOW UP CARE
For newborns and infants — After the infant is born, monitoring for side effects of antiretroviral medications should continue. In addtion, the baby should be screened for HIV. A complete blood count prior to the administration of ZDV. This blood test measures the cellular components of the blood (white blood cells, red blood cells, and platelets). Repeat testing to measure hemoglobin (the oxygen-carrying component of the blood) following completion of the six-week ZDV regimen and at 12 weeks of age. More intensive monitoring may be required for infants who have anemia at birth, who were born prematurely (before 37 weeks gestation), or whose mothers received combination antiretroviral therapy. Infants should be screened for HIV infection at birth, two weeks, one to two months, and three to six months of age, looking for HIV DNA (the genetic material of the virus inside of lymphocytes, which are blood cells that HIV infects). Prophylaxis for PCP (eg, trimethoprim-sulfamethoxazole [Bactrim]) should be started following completion of ZDV therapy at six weeks of age because infants are at risk for acquiring this infection, even before HIV infection is diagnosed. Therapy is continued until an HIV test is negative at four months of age. If the infant is HIV-infected, this treatment should be continued.
For women after delivery — As noted above, women who only received ZDV during pregnancy need to be evaluated after delivery to determine if ongoing antiretroviral therapy is needed. In addition, ongoing comprehensive care and supportive services, including HIV-related medical care, psychosocial support, and assistance with family planning and contraception, should be offered to all women.
Long-term follow-up of children Infants and children who were exposed to antiretroviral drugs during their mother's pregnancy should receive ongoing follow-up. Data on uninfected infants exposed to ZDV are reassuring and show no abnormalities in growth, the immune system, brain function and tumor development for six years. However, data are insufficient to determine whether these children have a long-term risk for organ system abnormalities or cancer. Children exposed to antiretroviral agents should have at least a yearly physical examination, including a gynecological evaluation for older adolescent girls.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. The National Institute of Child Health and Human Development
(301) 496-5133
(www.nlm.nih.gov/medlineplus)
Centers for Disease Control and Prevention (CDC)
Phone: (404) 639-3534
Toll-free: (800) 311-3435
(www.cdc.gov)
CDC (Centers for Disease Control and Prevention) National AIDS Hotline
English: (800) 342-2437
Spanish: (800) 344-7432
CDC National Prevention Information Network (NPIN)
Toll-free: (800) 458-5231
E-mail: info@cdcnpin.org
National Institute of Allergy and Infectious Diseases (NIAID)
Phone: (301) 496-5717
(www.niaid.nih.gov)
AIDS Clinical Trials Information Service (ACTIS)
Toll-free: (800) 874-2572
E-mail: actis@actis.org
(www.actis.org)
HIV/AIDS Treatment Information Service
Toll-free: (800) 448-0440
E-mail: atis@hivatis.org
(www.hivatis.org)
[1-7]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Davis, SF, Byers, RH, Lindegren, ML, et al. Prevalence and incidence of vertically acquired HIV infection in the United States. JAMA 1995; 247:952.
2. Lyall, EG, Stainsby, C, Taylor, GP, et al. Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status. BMJ 1998; 316:268.
3. 1999 USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. Clin Infect Dis 2000; 30 Suppl 1:S29.
4. Public Health Service Task Force recommendations for the use of antiretroviral drugs in pregnant women infected with HIV-1 for maternal health and for reducing perinatal HIV-1 transmission in the United States. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1998; 47(RR-2):1.
5. Sperling, RS, Shapiro, DE, McSherry, GD, et al. Safety of the maternal-infant zidovudine regimen utilized in Pediatric AIDS Clinical Trials Group 076 study. AIDS 1998; 12:1805.
6. The International Perinatal HIV Group. The mode of delivery and the risk of vertical transmission of human immunodeficiency virus type 1: A meta-analysis of 15 prospective cohort studies. N Engl J Med 1999; 340:977.
7. United States Public Health Service recommendations for human immunodeficiency virus counseling and voluntary testing for pregnant women. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 1995; 44(RR-7):1.
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