Pharmacologic management of constipation in the critically ill patient

Study Objective. To compare the effectiveness of common laxatives in producing a bowel movement in patients admitted to a medical intensive care unit (MICU). Design. Retrospective medical record review. Setting. MICU of an academic medical center. Patients. Ninety-five patients admitted to the MICU from July 1-October 31, 2004. Measurements and Main Results. Fifty patients satisfied the inclusion criteria. Patient-specific data such as age, weight, sex, length of MICU stay, Acute Physiology and Chronic Health Evaluation (APACHE) II score, dietary intake, opioid intake, laxative intake, and bowel movements were recorded during the first 96 hours of admission. Logistic regression analysis was used to compare patients who did and did not have a bowel movement. Of the 50 patients, 25 did not have a bowel movement during the first 96 hours of MICU admission. Patients given a stimulant laxative (senna, bisacodyl) and/or an osmotic laxative (lactulose, milk of magnesia) were more likely to have a bowel movement (odds ratio [OR] 26.6, 95% confidence interval [CI] 3.2-221, p=0.002). Opioid intake, expressed as logarithmic morphine equivalents, was negatively associated with occurrence of a bowel movement (OR 0.76, 95% CI 0.59-0.97, p=0.027). Disease severity, as determined by APACHE II score, was also negatively associated with a bowel movement (OR 0.84, 95% CI 0.7-0.99, p=0.04). Conclusion. Critically ill patients have a high frequency of constipation, and opioid therapy is a significant risk factor. Routine administration of stimulant or osmotic laxatives should be considered for this patient population.