Comparison of Efficacies of Different Loading Doses of Dexmedetomidine in Endoscopic Retrograde Cholangiopancreatography

Objective To evaluate the influences of different loading doses of dexmedetomidine(DEX)combined with propofol for general anesthesia on circulation and stress reaction in endoscopic retrograde cholangiopancreatography(ERCP).Methods Ninety patients scheduled for ERCP were randomly divided into two groups,with 45 patients in each group.Group D1 and group D2 were given intravenous infusion of DEX 0.5and 1.0μg·kg-1 before operation,respectively,pump injected 10 minutes.Then,all patients received intravenous infusion of 50 mL DEX 0.6μg·kg-1.In addition,all patients were injected with propofol 1.0mg·kg-1 at 2minutes before operation,followed by intravenous infusion of propofol 4-7 mg·kg-1.The mean arterial pressure(MAP),heart rate(HR),respiratory rate(RR)and blood oxygen saturation(SPO2)were measured before administration(T0),immediately after endoscope insertion(T1),10 minutes after beginning of operation(T2),20 minutes after beginning of operation(T3),30 minutes after beginning of operation(T5),and at the end of operation(T6).Furthermore,times of body movement/cough,times of SPO2≤90% or RR≤9 time·min-1,awakening time,operation time,propofol dosage,and fentanyl dosage were recorded.Moreover,5mL venous blood was drawn at T0 and T3 to determine the serum levels of adrenaline.Results Compared with group D1,MAP and HR at T4-T6,dosages of propofol and fentanyl,adrenaline levels at T3,and incidence of movement/cough significantly decreased in group D2(P0.05).However,the incidence of respiratory depression and bradycardia in group D2 was significantly higher than that in group D1(P0.05).Conclusion Intravenous infusion of dexmedetomidine with a loading dose of 0.5μg·kg-1 can be safely used in the general anesthesia for ERCP.In addition,it can effectively control intraoperative stress reaction and maintain hemodynamic stability.