Background: The efficacy of oral chlorhexidine (oCHG) for decontamination in intensive care unit (ICU) patients is controversial. The purpose of this study was to evaluate the effect of oCHG decontamination on the incidence of pneumonia, sepsis, and death in ICU patients. Methods: The Philips eICU database version 2.0 was queried for patients admitted to the ICU for ≥48 hours in 2014-2015. The primary outcome of interest was death in the ICU. Secondary outcomes were a diagnosis of pneumonia or sepsis. Patients with pneumonia or sepsis diagnosed within the first 48 hours of ICU admission were excluded from the outcome analyses. Univariable analysis was performed comparing age, gender, race, severity of illness scores, hospital characteristics, and oCHG order. Multivariable logistic regression was performed using univariable results with p < 0.05. Results: Of the 64,904 patients from 186 hospitals, 22.1% (n = 14,333) had oCHG ordered. The overall mortality rate was 6.9% (n = 4,449) and the mortality rate in patients receiving oCHG was 10.6% (n = 1,518; p < 0.001). After controlling for confounding factors, oCHG remained an independent risk factor for death (odds ratio [OR] 1.25; 95% confidence interval [CI] 1.16-1.34). After excluding patients with an early diagnosis of pneumonia, the overall pneumonia incidence was 2.6% (n = 1,431) and the incidence in patients having oCHG was 4.2% (n = 517; p < 0.001). However, multivariable logistic regression revealed no significant difference in the risk of pneumonia with oCHG (OR 0.97; 95% CI 0.85-1.09). After excluding patients with an early diagnosis of sepsis, the overall rate of sepsis was 1.8% (n = 949) and for patients with oCHG, the rate was 3.3% (n = 388; p < 0.001). After controlling for other confounders, oCHG remained an independent risk factor for sepsis (OR 1.37; 95% CI 1.19-1.59). Conclusions: A chlorhexidine mouthwash order is associated with increased odds of death and sepsis without decreased odds of pneumonia in a heterogeneous cohort of ICU patients. Additional studies are needed to understand better the effect of oCHG on outcomes.
Keywords: ICU death; chlorhexidine; pneumonia; sepsis.