Guidelines Issued on Antibiotic Prophylaxis for Gynecologic Procedures
News Author: Laurie Barclay, MD
CME Author: Charles P. Vega, MD, FAAFP
CME/CE Released: 04/30/2009 ; Valid for credit through 04/30/2010
April 30, 2009 — The American College of Obstetricians and Gynecologists (ACOG) has issued a practice bulletin on antibiotic prophylaxis for gynecologic procedures. The new guidelines, which replace a previous practice bulletin, are published in the May issue of Obstetrics & Gynecology, with the aim of reviewing the evidence for surgical site infection prevention and appropriate antibiotic prophylaxis for gynecologic procedures.
"State-of-the-art aseptic technique has been associated with a dramatic decrease in surgical site infections, but bacterial contamination of the surgical site is inevitable," write David Soper, MD, and colleagues from ACOG. "The in vivo interaction between the inoculated bacteria and a prophylactically administered antibiotic is one of the most important determinants of the state of the surgical site. Systemic antibiotic prophylaxis is based on the belief that antibiotics in the host tissues can augment natural immune-defense mechanisms and help to kill bacteria that are inoculated into the wound."
The most common surgical complication continues to be surgical site infection, occurring in up to 5% of patients undergoing operative procedures. Consequences of surgical site infection include longer hospitalization and increased healthcare costs.
Although the selective use of antibiotic prophylaxis has been one of the major advances in infection control practices, indiscriminate use of antibiotics has promoted the emergence of antibiotic-resistant bacteria. Individual patients as well as institutions experience negative effects when antibiotic resistance develops, mandating that clinicians understand when antibiotic prophylaxis is indicated and when it is not appropriate.
The choice of an appropriate antimicrobial agent for prophylaxis should take into account that the agent selected must be of low toxicity, have an established safety record, not be used routinely to treat serious infections, have a spectrum of activity including the microorganisms most likely to cause infection, achieve therapeutic concentration in relevant tissues during the procedure, be administered for a short time, and be administered in a manner that will ensure its presence in surgical sites at the time of the incision.
"The cephalosporins have emerged as the drugs of choice for most operative procedures because of their broad antimicrobial spectrum and the low incidence of allergic reactions and side effects," the guidelines authors write. "Cefazolin (1 g) is the most commonly used agent because of its reasonably long half-life (1.8 hours) and low cost. Most clinical studies indicate that it is equivalent to other cephalosporins that have improved in vitro activity against anaerobic bacteria in clean-contaminated procedures such as a hysterectomy."
After a review of the available literature and clinical studies, the ACOG panel made the following Level A recommendations and conclusions, based on good and consistent scientific evidence:
• Preoperative, single-dose antimicrobial prophylaxis is recommended for women undergoing hysterectomy.
• Antibiotic prophylaxis is not indicated at the time of intrauterine device insertion because pelvic inflammatory disease occurs uncommonly whether antibiotic prophylaxis is used.
• For elective suction curettage abortion, antibiotic prophylaxis is indicated.
• For patients undergoing diagnostic laparoscopy, antibiotic prophylaxis is not recommended.
The ACOG made the following Level B recommendations and conclusions, based on limited or inconsistent scientific evidence:
• Hysterosalpingography can be performed without prophylactic antibiotics in patients with no history of pelvic infection. However, to reduce the incidence of pelvic inflammatory disease after hysterosalpingography, antibiotic prophylaxis should be given if hysterosalpingography shows dilated fallopian tubes.
• In the general patient population, routine antibiotic prophylaxis is not recommended for hysteroscopic surgery.
• In patients with a history of penicillin allergy not thought to be immunoglobulin E mediated (immediate hypersensitivity), cephalosporin prophylaxis is acceptable.
• Before undergoing hysterectomy, patients with preoperative bacterial vaginosis should be treated.
The ACOG made the following Level C recommendations and conclusions, based primarily on consensus and expert opinion:
• For patients undergoing exploratory laparotomy, antibiotic prophylaxis is not recommended.
• For patients with a history of pelvic inflammatory disease or tubal damage noted at the time of the procedure, prophylaxis may be considered for transcervical procedures such as hysterosalpingography, chromotubation, and hysteroscopy.
• Cephalosporin antibiotics should not be given to patients with a history of an immediate hypersensitivity reaction to penicillin.
• Before undergoing urodynamic testing, women should have pretest screening for bacteriuria or urinary tract infection by urine culture or urinalysis, or both. Antibiotic treatment should be given to women with positive test results.
A performance measure proposed by the ACOG authors is the percentage of women undergoing hysterectomy who received preoperative antibiotic prophylaxis.
"Cephalosporin prophylaxis is acceptable in those patients with a history of penicillin allergy not believed to be immunoglobulin E mediated (immediate hypersensitivity)," the guidelines authors conclude. "Metronidazole or clindamycin alone have been shown to reduce infection after hysterectomy, but broadening coverage results in a further lowering of infection rates. For this reason, combination regimens are recommended for use in women with an immediate hypersensitivity reaction to penicillin."
Obstet Gynecol. 2009;113:1180-1189.
Clinical Context
Infection is a common complication after any surgery, but gynecologic procedures merit special consideration regarding prevention of postoperative infection. Procedures involving the vagina can expose wounds to both aerobes and anaerobes, and the presence of bacterial vaginosis can significantly increase the risk for posthysterectomy cuff cellulitis. Procedures that breach the endocervix can potentially distribute pathogens to the endometrium and fallopian tubes. However, in practice, infection after such procedures is rare and often occurs after previous pelvic inflammatory disease.
The current ACOG Practice Bulletin highlights the best practice of using prophylactic antibiotics for gynecologic procedures.
Study Highlights
- Prophylactic antibiotics are recommended for the following procedures:
- Hysterectomy
- Urogynecology procedures involving mesh
- Hysterosalpingogram or chromotubation
- Induced abortion
- Dilation and evacuation
- Antibiotics are not required before the following procedures:
- Diagnostic or operative laparoscopy
- Laparoscopic tubal sterilization
- Hysteroscopy
- Intrauterine device insertion
- Endometrial biopsy
- When required, antibiotics should only be administered immediately before the procedure, and longer cases may require repeat dosing at 1 to 2 times the half-life of the drug. For cefazolin, this means that repeated dosing is necessary at 3 hours of operative time.
- The dosage of the prophylactic antibiotic should be increased when the patient's body mass index exceeds 35 kg/m2. The standard 1-g dose of cefazolin should be doubled to 2 g for such patients.
- Cefazolin is the most popular choice for antibiotic prophylaxis, but most trials demonstrate that no one antibiotic regimen is superior to another for the prevention of infection after hysterectomy.
- Patients with bacterial vaginosis should be treated with metronidazole for at least 4 days, including both the preoperative and postoperative periods.
- Because patients with dilated fallopian tubes have a higher risk for pelvic inflammatory disease after hysterosalpingography, women with this finding should receive doxycycline 100 mg twice daily for 5 days after the procedure.
- Research has demonstrated that even women without a history of pelvic inflammatory disease benefit from prophylactic antibiotics before suction curettage for elective abortion. Women undergoing suction curettage for a missed abortion should also receive antibiotic prophylaxis.
- The most effective and least expensive prophylactic antibiotic regimen for abortion is doxycycline 100 mg at 1 hour before the procedure followed by 200 mg after the procedure.
- Mechanical bowel preparation does not appear to be necessary before gynecologic procedures.
- Bacteruria should be treated before urodynamic testing, and clinicians should also consider daily antibiotic prophylaxis in women discharged with an indwelling urinary catheter.
- In women with penicillin allergy, cephalosporins should be avoided only in women with immediate hypersensitivity, which is the most severe immediate reaction. Metronidazole, clindamycin, and quinolone antibiotics may be used as alternative prophylactic agents in such patients.
Clinical Implications
- Gynecologic procedures can carry special risks for postoperative infection. Procedures involving the vagina can expose wounds to aerobic and anaerobic bacteria, and bacterial vaginosis increases the risk for posthysterectomy infection. Infection is rare after endocervical procedures, but the risk for infection is increased in women with a history of pelvic inflammatory disease.
- The current practice guideline states that prophylactic antibiotics should be used before hysterectomy, hysterosalpingogram, and induced abortion, but not before operative laparoscopy, routine hysteroscopy, or insertion of an intrauterine device.
