Practice Guidelines

ACOG Releases Guidelines on Antibiotic Prophylaxis for Gynecologic Procedures

CARRIE ARMSTRONG

Although aseptic surgical techniques have dramatically reduced the incidence of surgical site infections, these infections remain the most common surgical complication, affecting up to 5 percent of postoperative patients. Selective use of antibiotics is effective for infection prophylaxis, but this benefit must be weighed against the risk for selection of antibiotic-resistant bacteria. The American College of Obstetricians and Gynecologists (ACOG) reviewed the evidence for appropriate antibiotic prophylaxis in women undergoing gynecologic procedures.

Microorganisms from the patient's skin or vagina are the pathogenic source in most surgical site infections. These organisms are usually aerobic gram-positive cocci (e.g., staphylococci) but also may include fecal flora (e.g., anaerobic bacteria, gram-negative anaerobes) when incisions are made near the perineum or groin. Only a narrow window of antimicrobial effectiveness is available, requiring that antibiotics be administered shortly before or at the time of bacterial inoculation (i.e., when the incision is made, the vagina is entered, or the pedicles are clamped). A delay of only three hours can result in ineffective prophylaxis. Data indicate that for lengthy procedures, administering additional intraoperative doses of an antibiotic can maintain adequate levels throughout the surgery. An additional dose also may be appropriate in patients who have lost more than 1,500 mL of blood.

Laparotomies and laparoscopies do not breach surfaces colonized with vaginal bacteria, and infections after these procedures more often result from contamination with skin bacteria. Hysterosalpingography, sonohysterography, intrauterine device (IUD) insertion, endometrial biopsy, and dilation and curettage may introduce endocervical and upper vaginal bacteria into the endometrium and fallopian tubes. Physicians should consider the polymicrobial nature of these infections when choosing a treatment for endometritis or pelvic inflammatory disease.

Hysterectomy

Women undergoing abdominal or vaginal hysterectomy should receive a single dose of antibiotics. Most studies show no particular regimen to be superior to any other. Antibiotic prophylaxis is a reasonable option in women undergoing laparoscopically assisted hysterectomy, although no evidence is available to support this use. Bacterial vaginosis is a risk factor for surgical site infection after hysterectomy. Treatment of bacterial vaginosis with metronidazole (Flagyl) for at least four days, beginning just before surgery, significantly reduces vaginal cuff infection in patients with abnormal flora.

IUD Insertion and Endometrial Biopsy

Most of the risk of IUD-related infection occurs in the first few weeks to months after insertion, which suggests that contamination of the endometrial cavity during the procedure is the infecting mechanism. However, four randomized clinical trials found that pelvic inflammatory disease is uncommon after IUD insertion regardless of whether antibiotic prophylaxis is used.

A Cochrane review found that administration of doxycycline (Vibramycin) or azithromycin (Zithromax) before IUD insertion confers little benefit. ACOG concludes that prophylactic antibiotic use provides no benefit in women with negative screening results for gonorrhea and chlamydia before IUD insertion.

No data are available on infectious complications of endometrial biopsy. However, the incidence of such complications is thought to be negligible, and ACOG recommends that this procedure be performed without the use of antibiotic prophylaxis.

Laparoscopy and Laparotomy

No data are available to recommend antibiotic prophylaxis in women undergoing abdominal surgery that does not involve vaginal or intestinal procedures. Antibiotic prophylaxis is not indicated for diagnostic laparoscopy.

Hysterosalpingography, Sonohysterography, and Hysteroscopy

Postoperative pelvic inflammatory disease is an uncommon but potentially serious complication in patients undergoing hysterosalpingography. Patients with dilated fallopian tubes at the time of the procedure are at greater risk than women with nondilated tubes. Antibiotic prophylaxis is not recommended for patients with no history of pelvic infection. If the procedure demonstrates dilated fallopian tubes, 100 mg of doxycycline may be given twice daily for five days. In women with a history of pelvic infection, doxycycline can be administered before the procedure and continued if dilated fallopian tubes are found.

No data are available on which to base recommendations for women undergoing sonohysterography, but reported rates of postprocedure infection are low. The risks of sonohysterography probably are similar to those of hysterosalpingography, and the same considerations should be taken into account.

Infectious complications after hysteroscopic surgery are uncommon (0.18 to 1.5 percent of patients). A prospective study evaluating the effectiveness of amoxicillin/clavulanate (Augmentin) in preventing bacteremia associated with the procedure found no significant difference in postoperative infection between treated patients and the placebo group. Therefore, ACOG does not recommend routine antibiotic prophylaxis in women undergoing this procedure.

Surgical Abortion

A meta-analysis of 11 placebo-controlled, blinded clinical trials found that women who were given periabortal antibiotics had a 42 percent overall decreased risk of infection. ACOG concludes that antibiotic prophylaxis is effective in women undergoing surgical abortion, regardless of risk. The optimal antibiotic and dosing regimens are unclear.

Preoperative Bowel Preparation

Appropriate prophylaxis for women undergoing surgery that may involve the bowel includes a mechanical bowel preparation without oral antibiotics and the use of a broad-spectrum parenteral antibiotic administered immediately before surgery.

AHA Publishes Guidelines on CVD Prevention in Women

SHERRI DAMLO

See related article on pg. 984.

Cardiovascular disease (CVD) is the most common cause of mortality among women, and it accounts for one third of all deaths. More women than men die each year from CVD in the United States. The public health impact of CVD on women is not solely related to mortality because advances in medicine have helped many women survive the disease. However, with the continued increase in the average life expectancy, the burden of CVD on women will also continue to rise.

CVD is often preventable in women, and even modest control could have a large impact. By reducing the rate of death from chronic diseases by 2 percent over one decade, it is estimated that 36 million lives could be saved.

Although some exceptions do exist, the guidelines presented by the American Heart Association (AHA) to prevent CVD in women do not differ for men. However, health care professionals should be aware that some of these recommendations are contraindicated in women who are pregnant or who want to become pregnant. This update represents the most current clinical recommendations for the prevention of CVD in women 20 years and older.

Risk Factors

Women who have one or more risk factors for heart disease, evidence of subclinical disease with or without risk factors, poor exercise capacity, or unhealthy lifestyles may be at risk of CVD (Figure 1). Factors such as medical and lifestyle history, Framingham risk score, and family history of CVD and other genetic conditions (e.g., familial hypercholesterolemia) should be considered when determining a patient's risk of CVD (Table 1).

Table 1. CVD Risk in Women
Risk level	Criteria
High risk	10-year Framingham global risk > 20 percent* Abdominal aortic aneurysm Cerebrovascular disease Diabetes mellitus End-stage or chronic renal disease Established coronary heart disease Peripheral arterial disease
At risk	Evidence for subclinical vascular disease Metabolic syndrome One or more major risk factors for CVD, including: Dyslipidemia Family history of premature CVD (younger than 55 years in male relative and younger than 65 years in female relative) Hypertension Obesity, especially central adiposity Physical inactivity Smoking cigarettes Unhealthy diet Poor exercise capacity on treadmill test and/or abnormal heart rate recovery after stopping exercise
Optimal risk	Framingham global risk < 10 percent, a healthy lifestyle, and no risk factors
CVD = cardiovascular disease. *-Or high risk based on other population-adapted tool to assess global risk. Adapted from American Heart Association. Evidence-based guidelines for cardiovascular disease prevention in women: 2007 update. Circulation 2007 [In press].

Clinical Recommendations

Recommendations for the prevention of CVD in women are based on the level of evidence to support a clinical recommendation as well as other factors, such as their practical application in randomized controlled trials with women. They are divided into the following categories: lifestyle interventions, major risk-factor interventions, and preventive drug interventions.

lifestyle interventions

Cigarette Smoking. Counseling women against smoking is recommended, as is nicotine replacement or another indicated pharmacotherapy combined with participation in a behavioral or formal smoking cessation program. Women should also try to avoid secondhand smoke.

Physical Activity. Women at risk of CVD should aim for a minimum of 30 minutes of moderate exercise (e.g., brisk walking) on most, and preferably all, days of the week and 60 to 90 minutes of daily moderate exercise for those who need to lose weight or sustain weight loss.

Weight Maintenance. To maintain or lose weight, it is recommended that women find an appropriate balance of physical activity and caloric intake. Body mass index should be between 18.5 and 24.9 kg per m2, and waist circumference should not exceed 35 inches.

Dietary Intake. A high intake of fruits and vegetables is recommended for women at risk. Selecting whole-grain, high-fiber foods and consuming oily fish at least twice a week is recommended. Dietary cholesterol should be less than 300 mg per day, and saturated fat should make up no more than 7 to 10 percent of the diet; women at risk of hypercholesterolemia should have diets with less than 7 percent saturated fat and less than 200 mg of cholesterol each day.

In conjunction with diet, omega-3 fatty acids in capsule form may be considered for women with coronary heart disease (CHD).

Rehabilitation. Women who have had a recent cerebrovascular event; acute coronary syndrome or coronary intervention; peripheral arterial disease; new-onset or chronic angina; or symptoms of heart failure should be offered a comprehensive risk-reduction regimen (e.g., physician-guided community- or home-based exercise training program, cardiovascular or stroke rehabilitation).

Depression. Screening for depression in women with CHD should be considered.

major risk-factor interventions

Blood Pressure. Optimal blood pressure is less than 120/80 mm Hg. Physicians should encourage patients to achieve optimal blood pressure through weight control; sodium restriction; increased physical activity; and consumption of low-fat dairy products, fruits, and vegetables.

If blood pressure is 140/90 mm Hg or more, or if the patient has chronic kidney disease or diabetes with blood pressure of 130/80 mm Hg or more, pharmacotherapy is recommended. Unless contraindicated or other agents are indicated for specific vascular diseases, thiazide diuretics should be considered as part of the drug regimen. Beta blockers used alone or in conjunction with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), with the addition of thiazides as needed to control blood pressure, are recommended for the initial treatment of women at high risk of CVD.

Lipids. Lifestyle changes are recommended to achieve an optimal low-density lipoprotein (LDL) cholesterol level of less than 100 mg per dL (2.60 mmol per L), high-density lipoprotein (HDL) cholesterol level greater than 50 mg per dL (1.30 mmol per L), triglycerides less than 150 mg per dL (3.90 mmol per L), and non-HDL levels less than 130 mg per dL (3.35 mmol per L).

For women with CHD or another atherosclerotic CVD, with diabetes, or with a 10-year absolute risk of more than 20 percent, LDL-cholesterol-lowering drug therapy in conjunction with lifestyle therapy is recommended to achieve an LDL cholesterol level of less than 100 mg per dL. A reduction to less than 70 mg per dL (1.80 mmol per L) is considered reasonable for women with CHD who are already at very high risk (e.g., women with diabetes mellitus and coronary heart disease).

LDL-cholesterol-lowering therapy is recommended for moderate-risk women (multiple risk factors, and who had a 10-year absolute risk of 10 to 20 percent) if the LDL cholesterol level is 130 mg per dL or more despite lifestyle therapy. For low-risk women whose 10-year absolute risk is less than 10 percent, LDL-cholesterol-lowering therapy is recommended if the patient's LDL cholesterol level is 160 mg per dL (4.15 mmol per L) or more despite lifestyle therapy. Regardless of the absence or presence of other risk factors or CVD, LDL-cholesterol-lowering therapy is recommended if the patient's LDL is 190 mg per dL (4.90 mmol per L) or more despite lifestyle therapy.

For women at high risk and women with multiple risk factors and a 10-year absolute risk of 10 to 20 percent, consider the use of fibrate therapy or niacin (Niacor) when HDL cholesterol is low or when non-HDL cholesterol is elevated after an appropriate LDL cholesterol level is reached.

Diabetes. If an A1C level of less than 7 percent can be accomplished without significant hypoglycemia, lifestyle therapy and pharmacotherapy should be used as indicated in women with diabetes.

preventive drug interventions

Aspirin. Unless contraindicated, 75 to 325 mg per day of aspirin is recommended for women with CHD or another atherosclerotic CVD, diabetes, or with a 10-year absolute risk of more than 20 percent. For patients at high risk who are intolerant of aspirin, clopidogrel (Plavix) may be substituted.

For women 65 years and older, aspirin in a dosage of 81 mg daily or 100 mg every other day is recommended if blood pressure is controlled and the benefit for the prevention of myocardial infarction and ischemic stroke is likely to outweigh the risk of hemorrhagic stroke and gastrointestinal bleeding. The same recommendations apply for women younger than 65 years when the benefit for prevention of ischemic stroke will likely outweigh the adverse effects of aspirin therapy.

Beta Blockers. Unless contraindicated, beta blockers should be used indefinitely in all women with acute coronary syndrome; left ventricular dysfunction, with or without heart failure symptoms; and after myocardial infarction.

ACE Inhibitors/ARBs. For women with diabetes or who have had a myocardial infarction, or if clinical evidence suggests heart failure or a left ventricular ejection fraction of 40 percent or less, ACE inhibitors should be considered. ARBs should be used instead if the patient is intolerant to ACE inhibitors.

Aldosterone Blockade. Aldosterone blockade is recommended after a myocardial infarction in women who also have diabetes or heart failure or are already receiving therapeutic doses of an ACE inhibitor and beta blocker, but who do not have significant renal dysfunction or hyperkalemia.

Clinical Limitations

Variations in therapy adherence and patient characteristics exist, so the effectiveness of therapies prescribed in an office or hospital setting may vary widely from the efficacy and safety profiles shown in clinical trials. Therefore, the development of guideline recommendations has limitations that vary from one population to another. Many of the studies used to formulate the AHA guidelines did not include older women, especially those older than 80 years in whom CVD and other comorbidities are common. Health care professionals should use clinical judgment about the aggressiveness of preventive therapy provided to all women, especially those who are older.

Practice Guideline Briefs

ACOG Releases Guideline for Management of Postpartum Hemorrhage

Postpartum hemorrhage is responsible for almost 140,000 deaths per year worldwide and can cause serious morbidity. It can occur without warning; therefore, all physicians should be prepared to manage it properly. The American College of Obstetricians and Gynecologists (ACOG) has reviewed the risks associated with postpartum hemorrhage and released recommendations on its management. The full guideline was published in the October 2006 issue of Obstetrics & Gynecology.

The most common cause of hemorrhage is uterine atony. If a patient has excessive bleeding following delivery, the bladder should be emptied and a pelvic examination performed. Massage or compression of the uterine corpus can help slow bleeding and remove blood and clots. If the patient continues to hemorrhage, other causes should be explored (e.g., lacerations, genital tract hematomas, retained placenta, coagulopathy). Baseline studies, including complete blood count with platelets, prothrombin time, activated partial thromboplastin time, fibrinogen, and a type and cross order, should be ordered and repeated if clinically necessary.

First-line treatment of postpartum hemorrhage includes the administration of uterotonics. If these agents fail to stop contractions and bleeding, a tamponade can be effective. If the tamponade does not provide an adequate response, physicians should perform an exploratory laparotomy (a midline vertical incision to the abdomen is preferred because it provides the best possible exposure). There are several methods for controlling continued bleeding, including uterine curettage, uterine artery ligation, B-Lynch suture, hypogastric artery ligation, rupture repair, and hysterectomy.

Placenta accreta is one of the most common reasons for postpartum hysterectomy. Risk factors include placenta previa (with or without previous uterine surgery), previous myomectomy or cesarean delivery, Asherman's syndrome, submucous leiomyomata, and age older than 35 years. The presence of any of these risk factors should create a suspicion of placenta accreta, and the physician should take the appropriate precautionary steps, such as patient counseling, making blood products and clotting factors available, considering the use of cell saver technology, scheduling delivery when and where there is access to surgical personnel and tools, and assessing preoperative anesthesia.

Arterial embolization may be an option in patients with stable vital signs who have persistent bleeding. It can be performed to help stop bleeding after hysterectomy or as an alternative to a hysterectomy. If vital signs are unstable and the blood loss is significant, transfusion may be necessary. Surgical repair is required if a hemorrhage is caused by a ruptured or inverted uterus; the surgical method should be adapted to each individual patient, if possible. No matter what the cause, replacement of red cells in patients with postpartum hemorrhage is key.

LISA GRAHAM

Answers to This Issue's Clinical Quiz Q1. A Q2. C Q3. C Q4. D Q5. D Q6. D Q7. C Q8. A, B, C, D Q9. A, B, D Q10. B, C, D Q11. B, C,

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