Impact of Chlorhexidine Bathing on Antimicrobial Utilization in Surgical Intensive Care Unit

Abstract Background This secondary analysis compared antimicrobial utilization among surgical intensive care unit patients randomized to every other day chlorhexidine bathing (chlorhexidine) versus daily soap and water bathing (soap-and-water) using data from the CHlorhexidine Gluconate BATHing trial. Materials and methods Antimicrobial utilization was quantified using defined daily dose (DDD)/100 patient-days and agent-days/100 patient-days for systemic antimicrobials. Antivirals (except oseltamivir), antiparasitics, and prophylaxis agents were excluded. The 2018 anatomic therapeutic chemical/DDD index was used to calculate DDD. Agent-days were calculated as the sum of calendar days where antimicrobials were administered. Patient-days were defined as time patients were at risk for health care–acquired infections plus up to 14 d. Primary analyses were conducted using linear regression adjusted for baseline Acute Physiology and Chronic Health Evaluation II scores. Results Of 325 CHlorhexidine Gluconate BATHing trial patients, 312 (157 in soap-and-water and 155 in chlorhexidine) were included. The median (interquartile range) of total antimicrobial DDD/100 patient-days was 135.4 (75.2-231.8) for soap-and-water and 129.9 (49.2-215.3) for chlorhexidine. The median (interquartile range) of total antimicrobial agent-days/100 patient-days was 155.6 (83.3-243.2) for soap-and-water and 146.7 (66.7-217.4) for chlorhexidine. After adjusting for Acute Physiology and Chronic Health Evaluation II scores, chlorhexidine bathing was associated with a nonsignificant reduction in total antimicrobial DDD/100 patient-days (−3.9; 95% confidence interval, −33.9 to 26.1; P = 0.80) and total antimicrobial agent-days/100 patient-days (−10.3; 95% confidence interval, −34.7 to 14.1; P = 0.41). Conclusions Compared with daily soap and water bathing, every other day chlorhexidine bathing did not significantly reduce total antimicrobial utilization in surgical intensive care unit patients.