Chx Ipa Pvi Ipa & Pvi ‡ Chx : Ipa Chx : Pvi Ipa : Pvi Chx

www.thelancet.com Vol 384 October 11, 2014 1345 as 1–2% chlorhexidine in isopropyl alcohol, but we agree with Maiwald and colleagues that adequate studies to support or reject this hypothesis have not yet been done. Chlorhexidine in an alcoholic solution, however, is clearly superior to povidone-iodine for prevention of vascular catheter-related bloodstream infec tion. Maiwald and colleagues have been arguing since 2010 that the fact that isopropyl alcohol is in alcoholic solutions of chlorhexidine is the main reason why it is better than povidone-iodine, and infer that isopropyl alcohol alone might be the best cutaneous antiseptic for prevention of vascular CRBSI, but provide no outcome study data; rather, they publish repeated critiques of the studies of chlorhexidine, including ours. They should test their belief in the comparable effectiveness of 70% isopropyl alcohol to 2% aqueous chlorhexidine or 2% chlorhexidine in isopropyl alcohol in an adequately powered randomised clinical trial. If such a study was done, we would predict that 2% chlorhexidine, even in an aqueous solution, would prove sup erior to isopropyl alcohol alone because of the prolonged anti-infective activity chlorhexidine exerts at the skin surface after application, which is not seen with isopropyl alcohol because the anti-infective activity of alcohol ceases as soon as it has evaporated. This attribute of chlorhexidine is unique and we believe clinically highly relevant. Application of an aqueous chlorhexidine-impregnated dressing about the catheter immediately after insertion has been shown conclusively in large trials to substantially reduce the incidence of CRBSI, strongly affi rming the importance of long-term anti septic activity at the insertion site for maximum protection against CRBSI with short-term, non-cuff ed catheters and the effectiveness of aqueous chlorhexidine. Moreover, scheduled oral care with aqueous chlorhexidine has been shown in randomised trials to significantly reduce the incidence of 3 O’Grady NP, Alexander M, Dellinger EP, et al. Guidelines for the prevention of intravascular catheter-related infections. MMWR Recomm Rep 2002; 51: 1–29. 4 Pratt RJ, Pellowe CM, Wilson JA, et al. epic2: national evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England. J Hosp Infect 2007; 65 (suppl 1): S1–64. 5 Canadian Patient Safety Institute. Prevent central line infections: getting started kit. Edmonton: Canadian Patient Safety Institute, 2012. more than two decades ago. However, it has gained huge prominence in the vascular catheter community, has been cited more than 400 times, and was influential in helping to shape catheter guidelines around the world. Practically everyone who read and cited it believes that it unequivocally shows that chlorhexidine is better than either of the two competitors. We do not support this conclusion based on the evidence presented in the Article.