Chlorhexidine bathing and health care-associated infections among adult intensive care patients: a systematic review and meta-analysis

BACKGROUND Health care-associated infections (HAI) have been shown to increase length of stay, the cost of care, and rates of hospital deaths (Kaye and Marchaim, J Am Geriatr Soc 62(2):306-11, 2014; Roberts and Scott, Med Care 48(11):1026-35, 2010; Warren and Quadir, Crit Care Med 34(8):2084-9, 2006; Zimlichman and Henderson, JAMA Intern Med 173(22):2039-46, 2013). Importantly, infections acquired during a hospital stay have been shown to be preventable (Loveday and Wilson, J Hosp Infect 86:S1-70, 2014). In particular, due to more invasive procedures, mechanical ventilation, and critical illness, patients cared for in the intensive care unit (ICU) are at greater risk of HAI and associated poor outcomes. This meta-analysis aims to summarise the effectiveness of chlorhexidine (CHG) bathing, in adult intensive care patients, to reduce infection. METHODS A systematic literature search was undertaken to identify trials assessing the effectiveness of CHG bathing to reduce risk of infection, among adult intensive care patients. Infections included were: bloodstream infections; central line-associated bloodstream infections (CLABSI); catheter-associated urinary tract infections; ventilator-associated pneumonia; methicillin-resistant Staphylococcus aureus (MRSA); vancomycin-resistant Enterococcus; and Clostridium difficile. Summary estimates were calculated as incidence rate ratios (IRRs) and 95% confidence/credible intervals. Variation in study designs was addressed using hierarchical Bayesian random-effects models. RESULTS Seventeen trials were included in our final analysis: seven of the studies were cluster-randomised crossover trials, and the remaining studies were before-and-after trials. CHG bathing was estimated to reduce the risk of CLABSI by 56% (Bayesian random effects IRR = 0.44 (95% credible interval (CrI), 0.26, 0.75)), and MRSA colonisation and bacteraemia in the ICU by 41% and 36%, respectively (IRR = 0.59 (95% CrI, 0.36, 0.94); and IRR = 0.64 (95% CrI, 0.43, 0.91)). The numbers needed to treat for these specific ICU infections ranged from 360 (CLABSI) to 2780 (MRSA bacteraemia). CONCLUSION This meta-analysis of the effectiveness of CHG bathing to reduce infections among adults in the ICU has found evidence for the benefit of daily bathing with CHG to reduce CLABSI and MRSA infections. However, the effectiveness may be dependent on the underlying baseline risk of these events among the given ICU population. Therefore, CHG bathing appears to be of the most clinical benefit when infection rates are high for a given ICU population.