Impact of choice of skin preparation solution in cardiac surgery on rate of surgical site infection: a propensity score matched analysis.

Background: Antiseptic skin preparations containing chlorhexidine gluconate and povidone iodine are routinely used to reduce the risk of surgical site infection (SSI). This study assesses the efficacy of two alcohol-based solutions, 2% chlorhexidine-alcohol and 10% povidone iodine-alcohol, on the incidence of cardiac SSI.

Methods: A total of 738 consecutive patients undergoing cardiac surgery had skin preparation with 2% chlorhexidine gluconate in 70% isopropanol (ChloraPrep, BD Ltd, UK) were propensity matched to 738 patients with skin prepared with 10% povidone-iodine in 30% industrial methylated spirit (Videne Alcoholic Tincture, Ecolab Ltd, UK). Continuous, prospective SSI surveillance data were collected for all these patients. A retrospective analysis of prospectively collected perioperative data was performed.

Results: The overall rate of SSI was similar in the chlorhexidine-alcohol and povidone-iodine-alcohol groups (3.3% versus 3.8%; = 0.14; relative risk [RR] = 0.98; 95% confidence interval [CI] = 0.52-1.78). Superficial (1.2% versus 1.8%; = 0.18; RR = 0.97; 95% CI = 0.48-1.80) and deep incisional (1.2% versus 1.6%; = 0.24) SSI rates were also similar with 10% povidone-iodine-alcohol being marginally more effective against organ-space infections (0.8% versus 0.4%; = 0.05; RR = 0.38; 95% CI = 0.20-1.01).

Conclusion: Our analysis confirms that alcohol-based skin preparation in cardiac surgery with povidone-iodine reduces the incidence of organ-space infections with no significant superiority in preventing incisional SSI compared with chlorhexidine-alcohol.