Dexmedetomidine Versus Propofol Sedation Improves Sublingual Microcirculation After Cardiac Surgery: A Randomized Controlled Trial

Abstract

Objectives To compare the effects of dexmedetomidine and propofol on sublingual microcirculation in patients after cardiac surgery. Design A prospective, randomized, single-blind study. Setting University hospital. Participants Adult patients undergoing elective valve surgery with cardiopulmonary bypass. Interventions On arrival in the intensive care unit (ICU), patients were assigned randomly to receive either dexmedetomidine (0.2-1.5 μg/kg/h) or propofol (5-50 μg/kg/min) with open-label titration to a target Richmond Agitation-Sedation Scale of 0 to –3. Measurements and Main Results Sublingual microcirculation was recorded using sidestream dark-field imaging at ICU admission (baseline [T1]) and 4 hours (T2) and 24 hours after ICU admission (T3). At T2, median changes in perfused small-vessel density and the De Backer score from baseline were significantly greater in the dexmedetomidine group (n = 29) than in the propofol group (n = 32) (1.3 v 0 mm/mm2, p = 0.025; 0.9 v –0.1/mm, p = 0.005, respectively); median changes in small-vessel density and the proportion of perfused small vessels from baseline also tended to be higher in the dexmedetomidine group compared with the propofol group (1.0 v –0.1 mm/mm2, p = 0.050; 2.1% v 0.5%, p = 0.062, respectively). At T3, there still was a trend toward greater improvements in the small-vessel density, proportion of perfused small-vessels, perfused small-vessel density, and De Backer score from baseline in the dexmedetomidine group than in the propofol group. Conclusions This trial demonstrated that dexmedetomidine sedation may be better able to improve microcirculation in cardiac surgery patients during the early postoperative period compared with propofol.