Results of our recent randomized trial showed that preoperative skin antisepsis with chlorhexidine-alcohol is superior to iodine-alcohol for preventing surgical site infection (SSI) after cesarean. The superiority of chlorhexidine-alcohol has been attributed in part to its efficacy against methicillin-resistant staphylococcus aureus (MRSA). We tested the hypothesis that chlorhexidine-alcohol will have a greater impact on the rate of positive wound cultures and prevalence of MRSA than iodine-alcohol.
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. Treating physicians were encouraged to send aerobic and anaerobic wound cultures from subjects presenting with suspected SSI. The outcome measures for this analysis were rates of pathogenic bacterial growth and presence of MRSA. Analysis was by intention-to-treat.
1082 subjects (538 in the chlorhexidine-alcohol group and 544 in the iodine-alcohol group) were included in the intention-to-treat analysis. In all, 65 (6.0%) subjects developed SSI; 45 superficial and 20 deep. Wound cultures were sent for 32 subjects with suspected SSI and 84.4% (27/32) showed pathogenic bacterial growth. There was no significant difference in rates of pathogenic bacterial growth between the two groups (6/8 [75.0%] in the chlorhexidine-alcohol group vs 21/24 [87.5%] in the iodine-alcohol group, RR 0.86 [95%CI 0.56, 1.31). In all, 15.6% (5/32) of the cultures were positive for MRSA. There was no significant difference in the prevalence of MRSA in the two groups (1/8 [12.5%] vs 4/24 [16.7%], RR 0.75 [95%CI 0.10, 5.8).
MRSA is present by culture in a significant proportion of SSI after cesarean and was not impacted by chlorhexidine-alcohol antisepsis. MRSA is an important cause of clinically meaningful morbidity and should be targeted in measures of prevention and treatment of SSI after cesarean.(ClinicalTrials.gov: NCT01472549)
© 2016 Published by Elsevier Inc.