INTERVENTION: Surgical hand cleansing with conventional 10% povidone–iodine scrub, conventional 4% chlorhexidine scrub, or waterless rub (1% chlorhexidine gluconate and 61% ethyl alcohol).
Materials and methods: This study was a single-center, single-blind, randomized trial. Participants were recruited from the surgical staff members of Taipei Medical University-Shuang Ho Hospital between December 1, 2014 and January 31, 2015. This trial was approved by the institutional review boards of Taipei Medical University and registered with ClinicalTrials.gov, NCT02294604.
Outcomes and statistical analysis: Required Sample size was calculated based on an intermediate effect size of 0.25, power of 80%, and two-sided test with type I error of 5%. G*Power was conducted to carry out the calculation.21 Based on the abovementioned parameters, the estimated sample size was 231. The primary outcome of this study was the CFU count per plate of each partici pant before surgical hand disinfection, after surgical hand disinfection, and immediately after surgery. The centrality of continuous variables was expressed as the mean, whereas the degree of variations was presented as the standard error of the mean. Analysis of variance (ANOVA) was used to examine the group difference in the antiseptic effect at specific time points and for specific surgery durations. Within-group comparisons of CFU counts between time points were performed using the paired t test. To adjust for CFU counts before disinfection, analysis of covariance (ANCOVA) was used to compare the effectiveness of the antiseptic methods. Multiple linear regression was used to adjust for potential risk factors to determine the effectiveness of the antiseptic methods. The Statistical Analysis System (SAS), Version 9.4, was used for all statistical analyses.
RESULTS: The mean colony-forming unit (CFU) count were collected using the hand imprinting method before and after disinfection and after surgery. After surgical hand disinfection, CFU count of the conventional chlorhexidine (0.48 ± 0.22, P < 0.01) and waterless rub groups (1.38 ± 0.74, P < 0.05) was significantly lower than that of the conventional povidone group (4.29 ± 1.25). No significant difference was observed in the mean CFU count among the groups after surgery. Similar results were obtained when preexisting differences before disinfection were considered in the analysis of covariance. Furthermore, multivariate regression indicated that the antiseptic method (P = 0.0036), but not other variables, predicted the mean CFU count.
CONCLUSIONS: Conventional chlorhexidine scrub and waterless rub were superior to conventional povidone–iodine in bacterial inhibition. We recommend using the conventional chlorhexidine scrub as a standard method for perioperative hand antisepsis. Waterless rub may be used if the higher cost is affordable.
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