Incidence and risk factors for iatrogenic opioid withdrawal in medical critical care patients

ABSTRACT

INTRODUCTION/HYPOTHESIS: Prolonged exposure to opioids through analgosedation may lead to iatrogenic opioid withdrawal syndrome (IWS) once patients are extubated and weaned from sedation. With the lack of validated assessment tools, IWS is likely underdiagnosed in critically ill adult patients. METHODS: This was an IRB-approved, prospective, observational study assessing IWS based on Clinical Opiate Withdrawal Scale (COWS) from October 2019 to November 2020. Patients were included if they were ≥18 years, admitted to the critical care medicine (CCM) service, and received ≥24 hours of continuous opioid infusion. Patients were excluded if they were admitted for drug overdose, intracranial pathology, active COVID-19, transitioned to withdrawal of life support or hospice, remained GCS ≤8 and/or RASS < -2 throughout assessment period, prisoners, pregnant patients, or missing ≥2 assessments. Patients were assessed within 24 hours from opioid cessation and followed for 5 days. The primary outcome was the incidence of at least moderate IWS diagnosis assessed using COWS. Secondary outcomes included the incidence of mild IWS based on COWS, the incidence of IWS diagnosis based on a positive DSM-V score, the correlation between diagnosis of IWS by DSM-V and COWS, and the identification of risk factors for IWS. RESULTS: Ninety-two patients were included in the final analysis. Except for a higher prevalence of psychiatric history in the IWS-positive group, baseline characteristics were similar. Overall, 11 patients (12%) developed at least moderate IWS, based on COWS. There was a strong, positive correlation between DSM-V and COWS on the day COWS was the highest (rs(90)=0.64;p< 0.01). The IWSpositive group also had longer durations of opioid infusions, higher cumulative opioid infusion doses, higher mean daily doses, and higher infusion rates at any given time. No significant differences were found between the two groups for scheduled or PRN opioids after cessation of the opioid infusion. Logistic regression did not identify any independent predictors for the development of IWS. CONCLUSION: At least 12% of CCM patients who received ≥24 hours of continuous opioid infusions developed IWS. These patients had significantly longer durations, higher cumulative daily and total opioid doses, and higher opioid infusion rates.