936: IMPACT OF HIGHER PHENOBARBITAL DOSING ON BENZODIAZEPINE USE IN SEVERE ALCOHOL WITHDRAWAL SYNDROME

Abstract

Learning Objectives: No previous studies exist evaluating the incidence of rebound hypertension after the discontinuation of prolonged (≥ 72 hours) dexmedetomidine infusions. This effect has been reported in the literature with clonidine, a structurally and pharmacologically similar medication. The aim of this analysis is to determine the incidence of rebound hypertension associated with dexmedetomidine infusion cessation compared to that seen with other sedative medications. Methods: A retrospective, matched cohort study was conducted from June 1, 2014 through June 1, 2017 evaluating intensive care unit patients receiving either continuous infusions of dexmedetomidine or propofol or midazolam for at least 72 hours. The primary outcome was incidence of rebound hypertension after cessation of dexmedetomidine as compared to propofol or midazolam. Incidence of rebound hypertension, defined as requirement of medical intervention in the form of anti-hypertensive medications or re-initiation of dexmedetomidine, was assessed up to 24 hours following discontinuation of infusion. Secondary outcomes included the effect of cumulative dexmedetomidine dose as well as duration of dexmedetomidine infusion on incidence of rebound hypertension. Results: A total of 216 patients (54 dexmedetomidine and 162 propofol or midazolam) were included in the analysis. There was no difference in incidence of rebound hypertension in the dexmedetomidine or propofol and midazolam arms (16.7% vs 17.9%, p = 0.837). 73.7% of subjects included in the analysis who experienced rebound hypertension had pre-existing hypertension (p < 0.001). Weaning of the dexmedetomidine infusion, defined as the time from peak infusion rate until discontinuation, was significantly shorter in patients who experienced rebound hypertension (median of 4 vs 17 hours, p = 0.011) compared those who did not. Conclusions: When compared to either propofol or midazolam, dexmedetomidine was not associated with an increased incidence of rebound hypertension after discontinuation. Hypertension history appears to be associated with an increased risk of rebound hypertension, regardless of which sedative medication is selected. In patients with pre-existing hypertension, a longer weaning of dexmedetomidine may be warranted.