Is Admission to the Intensive Care Unit Associated with Chronic Opioid Use? A 4-Year Follow-Up of Intensive Care Unit Survivors

Purpose: To describe opioid use before and after intensive care unit (ICU) admission and to identify factors associated with chronic opioid use upto 4 years after ICU discharge. Methods: Retrospective review of adult patients admitted to the ICU at a tertiary care center between January 1, 2005, to December 31, 2008. We defined "nonuser," "intermittent," and "chronic" opioid status by abstinence, use in <70%, and >70% of days for a given time period, respectively. We assessed opioid use at 3 months prior to ICU admission, at discharge, and annually for upto 4 years following ICU discharge. Results: A total of 2595 ICU patients were included for surgical (48.6%), medical (38.4%), and undetermined (13%) indications. The study population included both elective (26.9%) and emergent (73.1%) admissions. Three months prior to ICU admission, 76.9% were nonusers, 16.9% used opioids intermittently, and 6.2% used opioids chronically. We found an increase in nonuser patients from 87.8% in the early post-ICU period to 95.6% at 48-month follow-up. Consequently, intermittent and chronic opioid use dropped to 8.6% and 3.6% at discharge and 2.6% and 1.8% at 48-month follow-up, respectively. Prolonged hospital length of stay was associated with chronic opioid use. Conclusion: Admission to ICU and duration of ICU stay were not associated with chronic opioid use.