Incidence and clinical manifestation of iatrogenic opioid withdrawal syndrome in mechanically ventilated patients

Objective: The incidence of iatrogenic opioid withdrawal syndrome (IOWS) in mechanically ventilated adults has been questioned in settings driven by analgosedation strategies. This study aimed to describe the incidence, risk factors and clinical impact of IOWS in mechanically ventilated adults. Methods: This prospective, observational study was performed between 1 January and 31 August 2018. IOWS was identified based on the presence of at least three signs or symptoms according to the Diagnostic and Statistical Manual 5th edition (DSM-5) criteria after opioid discontinuation or rate reduction. Incidence of IOWS, patient characteristics, opioid administration, and the impact of IOWS on the duration of mechanical ventilator and length of stay in the intensive care unit (ICU) were collected. Results: Thirteen out of 55 patients (23.6%) manifested withdrawal symptoms. Two patients in the non-withdrawal group also developed hypertensive urgency after opioid discontinuation. Patients who received rapid once-daily weaning, especially rate reduction more than 50 µg as fentanyl equivalent per hour, were associated with IOWS. However, there was no statistically significant difference in ventilator-free days and ICU-free days. Conclusions: These findings showed that approximately one-fourth of mechanically ventilated patients who received opioid infusion experienced IOWS. Monitoring for IOWS is recommended especially in patients who received rapid weaning rate of opioids. Future studies to develop IOWS assessment tools with the change of hemodynamic parameters should be performed. Trial registration: This trial was registered in ClinicalTrials.gov: identifier NCT03374722, date of registration 15 December 2018.