Skin preparation before surgery: options and evidence.

BACKGROUND: Despite many advances in surgical asepsis, surgical site infection (SSI) remains a challenging and costly problem. Decontamination of the skin with an antiseptic agent is standard practice before any trans-cutaneous invasive procedure, but the antiseptic agent of choice to best reduce the risk of SSI remains controversial.
METHODS: Review of relevant literature.
RESULTS: Many randomized controlled trials (RCTs) have evaluated chlorhexidine-based and iodine-based preparation solutions, with and without an alcohol component. Most of these trials are underpowered to detect differences in SSI rates. The largest modern RCT showed that a chlorhexidine-isopropyl alcohol preparation reduced the risk of SSI substantially compared with a povidone-iodine preparation without alcohol in clean-contaminated surgery. Many smaller RCTs have shown that chlorhexidine-isopropyl alcohol is superior to povidone-iodine plus isopropyl alcohol or iodine povacrylex plus isopropyl alcohol in pre-operative skin decontamination; whether or not this translates into lower SSI rates is unknown. A mixed treatment comparison of 10 RCTs concluded that alcohol-based preparations have a 98% probability of reducing the risk of SSI more effectively than aqueous-based preparations. Non-randomized observational studies have generally found no difference in SSI rates among various skin antiseptic preparations.
CONCLUSIONS: Alcohol-based agents are likely superior to aqueous agents. Chlorhexidine may decrease SSI rates compared with povidone-iodine, and chlorhexidine-isopropyl alcohol likely offers better skin decontamination before clean surgery than povidone-iodine plus isopropyl alcohol or iodine povacrylex plus isopropyl alcohol. The quality of the available data is moderate. Rigorous, well-powered RCTs with appropriate treatment comparisons are needed to establish the optimal and most cost-effective pre-operative skin preparation in various operations and wound classifications.