881: Impact of skin preparation type on post-cesarean infection in the setting of adjunctive azithromycin prophylaxis.

Abstract

The addition of azithromycin to standard cefazolin antibiotic prophylaxis for unscheduled cesarean (CD) reduces postoperative infections. Our objective was to compare frequency of infection by type of skin preparation used for CD (chlorhexidine, chlorhexidine-alcohol, chlorhexidine-alcohol-iodine, or iodine-alcohol), in the setting of adjunctive azithromycin. Secondary analysis of a multi-center randomized control trial of adjunctive azithromycin (500mg) vs. placebo in women who were ≥24 weeks gestation and undergoing unscheduled CD (i.e., during labor or after at least 4 hours of membrane rupture). The primary outcome of the current analysis was post-operative superficial or deep wound infections, as defined by CDC criteria. Type of skin prep was identified based on the policy at the hospital at the time of CD. Logistic regression with backward selection was used to adjust for azithromycin, BMI, GA at delivery, ethnicity, skin closure with staples, membrane rupture duration greater than 6 hours, and surgery length > 49 minutes in the final model. All 2013 women in the primary trial were included. Type of skin preparation at sites was mainly chlorhexidine-based (90%). The groups differed by several factors at baseline (Table 1), reflecting variation in population at centers. The unadjusted rates of wound infection ranged from 2.9-5.7% and did not differ significantly by type of skin preparation used (Table 2; p=0.061). No significant differences were noted after adjusting for azithromycin exposure and other potential confounders (Table 2). In women undergoing unscheduled CD in a trial of adjunctive azithromycin, the risk of wound infection was not influenced by the type of skin preparation used at the study centers.View Large Image Figure ViewerDownload Hi-res image Download (PPT)