Standard- versus High-Dose Dexmedetomidine for Sedation in the Intensive Care Unit

Background: Dexmedetomidine is a commonly used sedative in the intensive care unit (ICU), however the use of higher, off label dosing has yet to be elucidated. A dose limitation protocol was implemented at our institution allowing for comparison of dexmedetomidine doses. Objective: The purpose of this study is to evaluate time spent within goal Richmond Agitation Sedation Scale (RASS) range with standard-dosing of dexmedetomidine ≤1 mcg/kg/hour (SD group) compared to high-dose >1 mcg/kg/hour (HD group). Secondary outcomes included days requiring mechanical ventilation, concomitant sedation, and incidence of hypotension or bradycardia. Methods: This retrospective chart review of adult ICU patients at a single academic medical center included patients who required at least 24 hours of mechanical ventilation and received dexmedetomidine monotherapy for at least 4 hours. Patients were excluded for intubations at an outside hospital, continuous neuromuscular blocking infusions, or Glasgow Coma Score ≤4. Results: A total of 144 patients met inclusion criteria (n = 121 SD group and n = 23 HD group). The SD group spent a greater time within goal RASS range compared to the HD group (84.5% [IQR 47-100] vs 45.5% [IQR 30.1-85.4], P = .013). The SD group also had shorter durations of both dexmedetomidine infusion and mechanical ventilation, and required less concomitant sedation. There was no difference in hypotension or bradycardia. Conclusion: This study further adds to the literature that administration of high-dose dexmedetomidine does not appear to confer additional benefit over standard doses for ICU patients requiring mechanical ventilation. Application of this data may support lower institutional maximum doses.