Antibiotic Prophylaxis During Gynecologic Surgery: Are We Following the Recommendations?
Abstract & Commentary
By Rebecca H. Allen, MD, MPH
Assistant Professor, Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, Women and Infants Hospital, Providence, RI
Dr. Allen reports no financial relationships relevant to this field of study.
Synopsis: In this national cohort study, 13% of women undergoing gynecologic surgery where antibiotics were recommended received no antibiotics or the incorrect antibiotics. Conversely, among women undergoing procedures where no antibiotic prophylaxis was needed, 40% of patients received inappropriate antibiotics.
Source: Wright JD, et al. Use of guideline-based antibiotic prophylaxis in women undergoing gynecologic surgery. Obstet Gynecol 2013;122:1145-1153.
This population-based study from the united states utilized the Perspective database, which collects data from more than 500 acute care hospitals that includes all diagnoses, procedures, and billed services. It is estimated to capture between 15-20% of all hospital discharges in the country. The Perspective database is managed by Premier, a private company that audits the data regularly and may charge for its use. The investigators analyzed adult non-pregnant women who underwent outpatient or inpatient gynecologic surgery between 2003 and 2010. Surgeries were grouped into antibiotic-appropriate procedures (abdominal hysterectomy, vaginal hysterectomy, and laparoscopic-assisted vaginal hysterectomy) and antibiotic-inappropriate procedures (myomectomy, open and laparoscopic oophorectomy with or without salpingectomy, laparoscopic ovarian cystectomy, dilatation and curettage with or without hysteroscopy, and laparoscopic tubal ligation) according to the American College of Obstetricians and Gynecologists' (ACOG) guidelines.1 The authors obtained data on demographics, surgical volume, medical comorbidities, and antibiotic use.
A total of 1,036,403 women were included in the study: 545,332 (52.5%) who underwent antibiotic-appropriate procedures and 491,071 (47.4%) who underwent antibiotic-inappropriate procedures. Among the women in the group where antibiotics were indicated, 87.1% received the correct antibiotics, 2.3% received incorrect antibiotics, and 10.6% received no prophylaxis. In a multivariable model, predictors of correct antibiotic use were a more recent surgery, women living outside the eastern United States, women residing in nonmetropolitan centers, nonteaching hospitals, and higher-volume surgeons. Among women who underwent procedures for which antibiotics were not recommended, 40.2% of women received antibiotics. Predictors of receiving inappropriate antibiotics in a multivariable model included a more recent surgery, residing in a region outside the eastern United States, nonteaching hospitals, low-volume surgeons, and undergoing a laparotomy compared to laparoscopy. Overall, higher volume surgeons were 41% less likely to omit antibiotics when indicated and 13% less likely to prescribe antibiotics when they were not indicated.
COMMENTARY
The majority of gynecologic procedures are classified as either Clean (Class 1) or Clean-contaminated (Class 2) when the vagina is opened during surgery. The theory of antimicrobial prophylaxis is that antibiotics are given either shortly before or at the time of surgery in order to augment natural defenses. Repeat doses are not needed unless the procedure is lengthy (e.g., > 3 hours for cefazolin) or has an increased blood loss (> 1500 mL).1 Antibiotic doses should be increased in morbidly obese women.2 ACOG only recommends antibiotic prophylaxis for hysterectomy (abdominal, vaginal, or laparoscopic), urogynecology procedures, induced abortion (suction D&C or D&E), and hysterosalpingram/chromotubation in women with a history of pelvic inflammatory disease (PID) or dilated fallopian tubes. Other procedures such as ovarian cystectomy, oophorectomy, tubal sterilization, and myomectomy, whether via laparoscopy or laparotomy, do not require antibiotics nor does hysteroscopy or endometrial ablation (unless history of PID or dilated tubes).
This study took advantage of a national database that tracks more than 500 acute care hospitals in the United States and collects data on ICD-9 codes, as well as all billed items including diagnostic tests, medications, and other treatments for individual patients. Although we seem to be doing a good job giving indicated antibiotics (87.1%), gynecologists are definitely overusing antibiotic prophylaxis for other procedures (40.2%). Although some providers may think that antibiotics can't hurt, there are documented adverse reactions such as allergic reactions, diarrhea, and possibly Clostridium difficile, not to mention the long-term problem of increasing antibiotic resistance rates. In this study's multivariable analysis, the relative risks of receiving antibiotics when none were recommended for different predictors ranged from very weak to strong. For example, nonteaching hospitals were only 8% more likely to give inappropriate antibiotics compared to teaching hospitals (relative risk [RR], 1.08; 95% confidence interval [CI], 1.05-1.11). On the other hand, women undergoing open oophorectomy were 46% more likely to receive antibiotics than women undergoing laparoscopic oophorectomy (RR, 1.46; 95% CI, 1.44-1.49). I suspect that the weaker associations such as hospital teaching status, metropolitan vs nonmetropolitan area, and hospital volume were only statistically significant due to the number of subjects in the study. However, stronger factors such as surgeon volume and the tendency to give antibiotics for any type of laparotomy make more clinical sense. The authors of this study speculate that the inappropriate use of antibiotics may be related to a misguided attempt to comply with quality metrics.3 It is certainly true that we must make sure any quality metrics used to measure our performance as clinicians are grounded in high-quality scientific evidence. In our hospital, the decision regarding antibiotic prophylaxis for gynecologic surgery has been taken out of the surgeon's hands and given to the anesthesiologist! Apparently, even when order sets were available in the electronic medical record with recommended antibiotics, surgeons were not prescribing appropriate antibiotics. Before your hospital goes that route, make sure you are up to date on ACOG's antibiotic prophylaxis guidelines.
References
- ACOG Practice Bulletin Number 104. May 2009.
- Forse RA, et al. Surgery 1989;106:750-756.
- Baker DW, Qaseem A. Ann Intern Med 2011;155:638-640.
