Diarrhea in Mechanically Ventilated Patients: A Nested Multicenter Substudy

OBJECTIVE: The aim of this study was to examine the prevalence and incidence of diarrhea, diarrhea risk factors, processes of care, and clinical outcomes associated with diarrhea in invasively ventilated patients in the ICU. DESIGN: Bedside nurses prospectively documented each patient’s bowel movement (BM) using the Bristol Stool Chart type and number. Research Coordinators collected baseline and daily data evaluating risk factors for diarrhea and patient outcomes. The diarrhea definition was the World Health Organization definition of ≥3 loose or watery BMs (Bristol type 6 or 7) per day. We used Cox proportional hazards regression to evaluate risk factors and the association with the risk of death in the ICU. SETTING: Forty-four ICUs in Canada, the United States, and Saudi Arabia. PATIENTS: All 2,650 invasively ventilated critically ill patients were enrolled in this preplanned secondary analysis of a randomized trial that evaluated the probiotic Lactobacillus rhamnosus GG on infectious outcomes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 2,650 patients, the mean age ( sd ) was 59.8 (16.5) years, with an Acute Physiology and Chronic Health Evaluation II Score of 22.0 (7.8); 61.2% received inotropes/vasopressors on study day 1. Diarrhea occurred among 60.4% of patients and on 18.2% of ICU study days. Independent risk factors for diarrhea were a history of Clostridioides difficile infection, laxatives, and antibiotic use. Adjusted for these factors, enteral nutrition, particularly with moderate–high-protein content, also increased the risk of diarrhea. Univariable analysis suggested that diarrhea was associated with C. difficile testing, fecal management device insertion, and increased length of ICU and hospital stay. After adjusting for illness severity, mechanical ventilation, inotropes/vasopressors, renal replacement therapy, and severe infections, diarrhea was not associated with an increased risk of death. CONCLUSIONS: Diarrhea is common among invasively ventilated patients. Risk factors include a history of C. difficile , use of antibiotics, laxatives, and enteral nutrition, particularly moderate–high-protein composition feeds.