Adverse Hemodynamic Events Associated With Concomitant Dexmedetomidine and Propofol for Sedation in Mechanically Ventilated ICU Patients

Purpose: Nonbenzodiazepines are preferred for continuous sedation in mechanically ventilated intensive care unit (ICU) patients. Although dexmedetomidine and propofol have blood pressure lowering properties, limited data exist about the hemodynamic effects of concomitant administration. The purpose of this study was to compare the adverse hemodynamic event rate with concomitant dexmedetomidine and propofol compared to either agent alone in mechanically ventilated ICU patients. Methods: This retrospective cohort study was conducted at a university medical center. Adult ICU patients (>= 18 years) admitted between October 20, 2015, and January 25, 2018, and administered concurrent dexmedetomidine and propofol or either agent alone for >= 24 hours were included. Mean arterial pressure, heart rate, and sedative dosing requirements were assessed from initiation to 72 hours after initiation. The primary end point was comparing the incidence of hypotension among study groups. Secondary aims compared the incidence of tachycardia and bradycardia as well as clinical outcomes. Results: Overall, 276 patients were included among combination (n = 93), dexmedetomidine (n = 91), and propofol (n = 92) groups. The incidence of hypotension was significantly higher in patients administered concomitant dexmedetomidine and propofol (62.4%) compared to those administered dexmedetomidine (23.1%) or propofol (23.9%) alone (P < .0001). Adjunctive dexmedetomidine with propofol was also associated with higher rates of clinically relevant hypotension requiring treatment (P = .048). The tachycardia incidence in the concomitant, dexmedetomidine, and propofol groups were 30.1%, 28.6%, and 14.1%, respectively (P = 02). Only 1.4% (n = 4) of all study patients developed bradycardia. Concomitant therapy was an independent risk factor of hypotension compared to either dexmedetomidine (odds ratio [OR]: 6.7, 95% confidence interval [CI]: 2.61-17.3, P < .0001) or propofol (OR: 2.89, 95% CI: 1.24-6.74, P = .014) monotherapy. Patients experiencing hypotension were associated with worse clinical outcomes. Conclusion: Concomitant dexmedetomidine and propofol use in mechanically ventilated patients increased the risk of hypotensive events. Adjunctive dexmedetomidine with propofol administration in the critically ill warrants caution.