(420) Incidence of Constipation With Continuous Opioid Infusions in the Medical Intensive Care Unit

Introduction: The incidence of constipation in the intensive care unit (ICU) is variable, impacting 20 – 83% of patients, and has multiple risk factors, such as the use of opioids. Patients with constipation may have prolonged duration of mechanical ventilation and ICU length of stay. There have been few studies that have evaluated the management of constipation in this patient population and there is no consistent approach that exists. Additionally, the use of bowel stimulating medications may lead to complications such as diarrhea and increased Clostridioides difficile testing. It was hypothesized that constipation would occur frequently in those who were received at least 24 hours of a continuous opioid.

Methods: A retrospective cohort study was conducted in patients who were admitted to the medical ICU at a 488-bed, community teaching hospital between November 2021 and June 2022. Patients were included if they were at least 18 years of age and had received at least 24 hours of a continuous opioid infusion. The primary outcome was the incidence of constipation. Secondary outcomes included ICU length of stay, hospital length of stay, in-hospital mortality, duration of mechanical ventilation, and determination of risk factors associated with constipation. Both primary and secondary outcomes were evaluated using descriptive statistics. A logistic regression was also used to assess risk factors related to constipation.

Results: In the total of 149 patients reviewed, 94 (63.1%) patients developed constipation. Patients who developed constipation had late initiation of bowel regimen (52.1% vs. 32.7%, p=0.022), lower in-hospital mortality (15.2% vs. 38.2%, p=0.002), less frequent fecal management system placement (7.4% vs. 18.2%, p=0.047), and greater use of bisacodyl suppositories (22.3% vs. 9.1%, p=0.040). The multivariable regression model found that late initiation of a bowel stimulating agent was the only risk factor that was associated with constipation (Adjusted OR 2.165, 95% CI 1.056-4.439, p=0.035).

Conclusions: Constipation occurred frequently in the medical ICU and was associated with late initiation of a bowel regimen. More studies are needed to assess the timing of bowel regimens and specific agents used to prevent and treat constipation in this population.