Comparative effectiveness of skin antiseptic agents in reducing surgical site infections: a report from the Washington State Surgical Care and Outcomes Assessment Program.

Abstract

Surgical site infections (SSI) are an important source of morbidity and mortality. Chlorhexidine in isopropyl alcohol is effective in preventing central venous-catheter associated infections, but its effectiveness in reducing SSI in clean-contaminated procedures is uncertain. Surgical studies to date have had contradictory results. We aimed to further evaluate the relationship of commonly used antiseptic agents and SSI, and to determine if isopropyl alcohol has a unique effect. We performed a prospective cohort analysis to evaluate the relationship of commonly used skin antiseptic agents and SSI for patients undergoing mostly clean-contaminated surgery from January 2011 through June 2012. Multivariate regression modeling predicted expected rates of SSI. Risk adjusted event rates (RAERs) of SSI were compared across groups using proportionality testing. Among 7,669 patients, the rate of SSI was 4.6%. The RAERs were 0.85 (p = 0.28) for chlorhexidine (CHG), 1.10 (p = 0.06) for chlorhexidine in isopropyl alcohol (CHG+IPA), 0.98 (p = 0.96) for povidone-iodine (PVI), and 0.93 (p = 0.51) for iodine-povacrylex in isopropyl alcohol (IPC+IPA). The RAERs were 0.91 (p = 0.39) for the non-IPA group and 1.10 (p = 0.07) for the IPA group. Among elective colorectal patients, the RAERs were 0.90 (p = 0.48) for CHG, 1.04 (p = 0.67) for CHG+IPA, 1.04 (p = 0.85) for PVI, and 1.00 (p = 0.99) for IPC+IPA. For clean-contaminated surgical cases, this large-scale state cohort study did not demonstrate superiority of any commonly used skin antiseptic agent in reducing the risk of SSI, nor did it find any unique effect of isopropyl alcohol. These results do not support the use of more expensive skin preparation agents.