Antiseptic Skin Preparation Agents to Prevent Surgical Site Infection in Colorectal Surgery: A 3-Armed Randomized Controlled Trial

BACKGROUND: There is much debate surrounding the ideal antiseptic skin preparation agent to reduce postoperative surgical site infection. International guidelines suggest that chlorhexidine- and alcohol-containing compounds have superior efficacy. However, there are minimal clinical trials specifically looking at skin preparation agents for colorectal surgery. OBJECTIVE: The aim of this study was to compare the efficacy of chlorhexidine in alcohol versus povidoneiodine in alcohol versus povidone-iodine in aqueous solution for the prevention of surgical site infection in colorectal surgery. DESIGN: This is a prospective, 3-armed, randomized controlled trial. SETTING: This study was conducted at the 800-bed John Hunter Hospital and Newcastle Private Hospital, with all subspecialty services in New South Wales, Australia. PATIENTS: All eligible, consenting adults undergoing colorectal surgery between July 2015 and December 2018 were included. INTERVENTIONS: Patients were andomized to receive preincision skin preparation with one of the following: chlorhexidine in 70% alcohol, povidone-iodine in 70% alcohol, or povidone-iodine in aqueous solution. MAIN OUTCOME MEASURE: The primary measure was surgical site infection within 30 days. RESULTS: A total of 482 patients were randomized to chlorhexidine in alcohol, povidone-iodine in alcohol, or aqueous povidone-iodine. The overall surgical site infection rate was 22% (107/482). There was no difference in rates of surgical site infection: 20.6% (29/141), 22.8% (44/193), and 23.0% (34/148), respectively (p=0.5267). There was no difference in complication rates: 54.6% (77/141), 46.1% (89/193), and 49.3% (73/148), respectively (p=0.1762). The median length of stay was 6 days in all 3 groups. LIMITATIONS: This is a subset analysis of a larger clinical trial for all forms of incisional surgery (the NewSKIN Prep trial), and noninferiority cannot be assessed. Changes in government regulations resulted in a change from 0.5% chlorhexidine in 70% ethanol to 2% chlorhexidine in 70% ethanol during the trial. CONCLUSION: This large, prospective, randomized clinical trial appears to indicate that there is no difference in surgical site infection, complications, or length of stay among the 3 commonest forms of skin preparation in colorectal surgery.