Abstract
To determine the incidence of dexmedetomidine withdrawal in adult critically ill patients. DESIGN: This was a prospective, observational study of patients from November 2017 to December 2018. SETTING: Medical-surgical, cardiothoracic, and neurosurgical ICUs in a tertiary care hospital. PATIENTS: Adult critically ill patients on dexmedetomidine infusions for at least 3 days. INTERVENTIONS: Indicators of withdrawal were assessed at baseline and at least daily during the dexmedetomidine wean period. Delirium was assessed using the Confusion Assessment Method for the ICU. Sedation was assessed using the Richmond Agitation-Sedation Scale. The Withdrawal Assessment Tool-1 was performed and vital signs were recorded during each assessment. Patients were considered positive for dexmedetomidine withdrawal if they had two or more of the following symptoms: positive Confusion Assessment Method for the ICU, Richmond Agitation-Sedation Scale greater than +1, positive Withdrawal Assessment Tool-1 assessment, tachycardia (heart rate > 90 beats/min), and hypertension (systolic blood pressure > 140 mm Hg or mean arterial pressure > 90). MEASUREMENTS AND MAIN RESULTS: Forty-two patients were included in the study, with 64% of patients experiencing signs of dexmedetomidine withdrawal. The median time on dexmedetomidine for all patients was 9.6 days (5.8-12.7 d), and the median dose of dexmedetomidine received was 0.8 µg/kg/hr (0.5-1 µg/kg/hr). Of the patients who were positive for withdrawal, the most prevalent withdrawal symptoms observed included delirium, hypertension, and agitation (93%, 48%, and 33%, respectively). We found no correlation between chronic opioid tolerance and incidence of withdrawal symptoms. Peak dexmedetomidine doses greater than 0.8 µg/kg/hr and cumulative daily doses of dexmedetomidine greater than 12.9 µg/kg/d were associated with a higher incidence of withdrawal. CONCLUSIONS: The majority of patients in our study demonstrated signs that may be indicative of dexmedetomidine withdrawal. Peak and cumulative daily dexmedetomidine dose, rather than duration of therapy, may be associated with a higher incidence of withdrawal signs. Regular screening of patients on prolonged dexmedetomidine infusions is recommended to ensure safe and effective use in critically ill patients.