Influences of dexmedetomidine in doses of propofol and fentanyl and recovery from anesthesia

Objective To evaluate the potential sparing effects of dexmedetomidine(Dex) on propofol and fentanyl and suppression of sympathoadrenal responses to tracheal intubation and extubation and the influence in recovery from anesthesia.Methods A total of 24 patients(ASA Ⅰ-Ⅱ) undergoing selective operation practicing general anesthesia were randomly divided into 2 groups:Dex group(n=12) and control group(n=12).30 min before induction the patients in Dex group received 1 μg·kg-1 Dex diluted to 10 mL over 10 min by pumped infusion and the patients in control group simply recieved normal saline at the same way.The patients in both groups were pumped 0.4 mg·kg-1·min-1 propofol at the beginning of induction.When holding up jaw without bodymove,the patients received 1 μg·kg-1 fentanyl and 0.6 mg·kg-1 rocuronium,and were endotracheally intubated 1.5 min later.After being intubated successfully they received sevoflurane by inhalation instead of propofol.At the same time the patients in Dex group received 0.3 μg·kg-1·h-1 Dex till the operation finished and the patients in control group received normal saline at the same way.Sevoflurane ceased at the end of surgery.The dose of propofol duing induction and fentanyl during the entire operation were recorded.The HR and MAP of the patients were recorded when they entering the operation room(T0),being inserted laryngoscopy(T1),being endotracheally intubated(T2),opening their eyes after operation(T3),being extubated(T4) and 10 min after being extubated(T5).The postoperative respiration recovery time,time to open eyes and extubation time after operation were recorded.Results Compared with control group,the dose of propofol(mg·kg-1) during inducion was decreased by 21%(P0.01)and the dose of fentanyl during the entire operation was decreased by 38% in Dex group(P0.01).The MAP and HR in control group were rised significantly at T1,T2 and T4 compared with T0(P0.01).The MAP and HR at T1-T6 in Dex group had no significant change compared with T0.The MAP and HR in Dex group were decreased obviously at T1,T2 and T4 compared with control group(P0.01).The postoperative respiration recovery time,time to open eyes and extubation time had no significantly difference between two groups(P0.05).Conclusion Dex may reduce the dose of propofol duing induction and fentanyl during the entire operation and have hemodynamic-stabilizing effects during tracheal intubation and extubation while not prolonging the recovery time from anesthesia.