Effects of dexmedetomidine on cerebral blood flow in critically ill patients with or without traumatic brain injury: A prospective controlled trial

AbstractStudy objective: To examine the effect of dexmedetomidine on CBF in critical ill patients with or without TBI.Research design: Prospective controlled trial (ISRCTN57998533).Methods: Fifteen patients without TBI and 20 patients with TBI with a Glasgow Coma Scale score of 4–14 were assigned to CON or TBI groups, respectively. All patients received 1 μg kg−1 dexmedetomidine infused over 10 minutes, followed by a 0.4 μg kg−1 h−1 continuous infusion for 60 minutes. Blood pressure was maintained at the pre-sedation level with dopamine for all patients. The CBF and cerebral metabolic rate equivalent (CMRe) were measured before sedation and 70 minutes after dexmedetomidine administration.Results: Dexmedetomidine administration significantly decreased CBF in patients of the CON group (difference = 3.3 ml s−1, 95% confidence interval [CI] = 0.92–5.7 ml s−1, p = 0.008), without altering the CMRe and CMRe/CBF ratio. The dexmedetomidine-induced change of CBF, CMRe and CMRe/CBF was not significant in the TBI gr...