196: Does the relative efficacy of chlorhexidine-alcohol versus iodine-alcohol antisepsis differ between unscheduled and scheduled cesareans?


      Scheduled and unscheduled cesareans may be at different risks for surgical site infection (SSI). We tested the hypothesis that chlorhexidine-alcohol and iodine-alcohol skin antisepsis are differentially effective for preventing SSI at unscheduled compared with scheduled cesarean.

      Study Design

      This was a planned secondary analysis of a randomized trial in which pregnant women undergoing cesarean were randomly assigned to preoperative skin preparation with either chlorhexidine-alcohol or iodine-alcohol. The comparison groups were scheduled (planned, mostly without labor) and unscheduled (unplanned, mostly during labor) cesareans. The primary outcome was SSI within 30 days after cesarean based on the Centers for Disease Control Nosocomial Infections Surveillance System definitions. Outcomes were compared between the two groups, and the Mantel-Hansel test of homogeneity was used to test for interaction between antiseptic type and scheduled/unscheduled cesareans.


      Of 1082 subjects included in the intention-to-treat analysis, 640 (59.1%) were scheduled and 442 (40.9%) were unscheduled. The overall risk for SSI was significantly higher in unscheduled compared with scheduled cesareans (8.1% vs 4.5%, RR 1.80, 95%CI 1.12, 2.89). Chlorhexidine-alcohol was more protective than iodine-alcohol in scheduled (2.5% vs 6.5%, RR 0.38 95%CI 0.17, 0.85) and unscheduled cesareans (6.9% vs 9.4%, RR 0.73, 95%CI 0.39, 1.37), although the difference among unscheduled cesareans was not statistically significant (Table). The test of homogeneity (P=0.22) suggested comparable efficacy of chlorhexidine-alcohol in unscheduled and scheduled cesareans.


      Unscheduled cesarean is associated with a nearly two-fold higher risk for SSI compared with scheduled cesarean. Chlorhexidine-alcohol appears superior to iodine-alcohol for prevention of SSI in both types of cesarean. Our results suggest that chlorhexidine-alcohol should be the antiseptic of choice at both scheduled and unscheduled cesarean.