The Changes Of Plasma Orexin-A Dexmedetomidine And Propofol Assisted In Epidural Anesthesia Sedation

Objective: To investigate the plasma orexin-A changes of domestic dexmedetomidine and propofol used in epidural anesthesia.Methods:Fifty patients undergoing epidual anesthesia,ASA I or II,were randomly divided into two groups.DEX group(Group D,n=25)and popofol group(group P,n=25).In Group D,after epidural anesthesia,dexmedetomidine was intravenous pumped with loading dose 0.8ug/kg,15 min finished,then pumped with maintenance dose 0.2-0.8 ug·kg-1·h-1.In the Group P,after epidural anesthesia,propofol was intravenous pumped with 1.0 mg/kg in one minute,and then pumped with maintenance dose 1-3mg·kg-1·h-1 to maintain the Bispectral Index between 60 and 70.The expression of plasma orexin-A was mesured at pre using adjunctive drugs(T0),thirty minutes post using adjunctive drugs(T1),sixty minutes post using adjunctive drugs(T2),stopping dexmedetomidine and propofol infusion and calling the patient opening the eyes(T3).The time from stopping dex and propofol infusion the patient open the eyes and BIS>90 were also recorded.Ten patients were excluded : Two of them rejected the tial.Two of them did not receive allocated intervention because of during surgery pain,and four of them were excluded because of hemolysis,and four of them were excluded because of Surgery for less than one hour.Results:The time of group D calling patients opening eyes and the Bispectral Index≥90 is faster than group P.Compared with T0-T2 orexin-A in two groups were significantly increased at T3(P<0.01)。Compared with T0 orexin-A in the group D at T1-T2 was not significantly changes(P>0.05).Compared with T0 the expression of orexin-A at T1-T2 was decreased in group P(P<0.01)Conclusion:Propofol can reduces plasma orexin-A levels,while during the waken stage the plasma orexin-A release higher.During the dexmedetomidine anesthesia,the plasma orexin-A maintained at a high level,and during the waken stage the level increase higher.This phenomenom showed us that the orexin-A might be mechanism of dexmedetomidine easily awaken.