Is alcohol-based hand disinfection equivalent to surgical scrub before placing a central venous catheter?

Background: Waterless antiseptic surgical hand scrub (1% chlorhexidine gluconate and 61% ethyl alcohol, Avagard™; 3M Health Care, St. Paul, MN), alcohol-only cleanser (62% ethyl alcohol), and traditional surgical scrub (5-minute scrub with 4% chlorhexidine soap using a sterile scrub brush with water) are techniques used for hand cleansing and disinfection. We hypothesized that alcohol-only cleanser and waterless antiseptic scrub (Avagard) would be as effective as a traditional surgical scrub for hand cleansing before placement of central venous catheters.

Methods: Fingers of subjects were plate-cultured for 24 hours after 5 methods of hand cleansing: method 1: traditional surgical scrub (n = 49 plates produced by 14 subjects); method 2: traditional surgical scrub (5-minute scrub with water, brush, and 4% chlorhexidine soap) followed by a 15-minute break, then alcohol-only cleanser (62% alcohol) (n = 49 plates produced by 14 subjects); method 3: alcohol-only cleanser alone (n = 49 plates produced by 14 subjects); method 4: alcohol-only cleanser (62% alcohol), followed by a 15-minute break, then traditional surgical scrub (5-minute scrub with brush, and 4% chlorhexidine soap with water) (n = 49 plates produced by 14 subjects); and method 5: waterless surgical scrub (Avagard) alone (n = 116 plates produced by 38 subjects). The 15-minute break was introduced to allow a short period of recontamination, and to test for residual effects from prior cleansing.

Results: Alcohol-only cleanser alone (method 3) was significantly less effective than the traditional surgical scrub (method 1) (P < 0.001; 82% plate growth). Waterless surgical scrub (Avagard) (method 5) had a 0% observed difference (95% confidence interval [CI]: -14% to 11%) compared with the traditional 5-minute scrub (method 1) (P = 0.99; 16% plate growth). When a traditional surgical scrub was used first followed by a 15-minute period of recontamination, there was a 6% observed difference in method 2 from reference (method 1) (95% CI: -10% to 22%), and 0% observed difference in method 4 from reference (95% CI: -15% to 15%).

Conclusion: As the initial cleansing method, the alcohol-only cleanser (method 3) was significantly less effective than the traditional surgical scrub (method 1) (P < 0.001).