The Influence Of Sevoflurane And Isoflurane On Pharmacodynamics Of Rocuronium

Objective This study was design to invesgate the effects of sevoflurane and equivalentisoflurane on pharmacodynamics of rocuronium. Methods Thirty-six ASAⅠ—Ⅱmale patientswithout any neuromuscular disease undergoing elective radical gastrectomy under generalanesthesia were randomly divided into three groups of 12 patients each. In groupâ… , theanesthesia was maitained by continuous propofol and inhaling 67%N₂O, In group B, by inhaling1.0% sevoflurane-67% N₂O and In group C by0.7% isoflurane-67% N₂O. All patients werepremedicated with diazepam 0.2mg/kg, atropine 0.01mg/kg intramuscularly 0.5h beforeanesthesia. Fentanyl 0.1ug.kg^-1 was given intravously 10min before induce. After topicalanesthesia with 2 ml 1% Dicaine, anesthesia was induced with iv midazolam 0.01mg/kg,propofol 2-3mg/kg and fentanyl 2-4ug/kg. the trachea was intubated without the aid of a musclerelaxants, and general anestheia In group A, the anesthesia was maitained by continuous propofoland inhaling 67%N₂O, In group B, by inhaling 1.0% sevoflurane-67% N₂O and In group Cby0.7% isoflurane-67% N₂O. After the above mentioned stabilized for 5 minutes, Rocuronium(0.6mg/kg) was intravenously infused.The onset time(from the point finishing injection to maximaldepression of T₁),clinical duration(from the maximal depression to T₁ recovering 25% of thecontral value)were recorded. When T₁ recovering 25% of the contral value 0.25% rocuroniumbegan to be continuous injected by a mico-pump and T₁ was maintained 1～10% ,ROC wasstoped when continuous injected for 60 minutes.Calculate the amount of rocuronium administeredper minute,Record the time from ROC was stoped to T₁ recovering 25% and the rerovery index.Results Onset times of rocuronium in three groups were 89.1±17.2s,84.5±15.6s and 87.7±16.0s(P＞0.05); Clinical durations in group B and C were longer than that in group A(45.6±14.6min,43.4±13.1min.and 34.2±12.4min P＜0.01).The infusion rates of rocuronium to maitain 90-99%blockade in three groups were 6.71±1.83ug·kg^-1·min^-1,4.87±1.43ug·kg^-1·min^-1 and 5.43±1.63ug·kg^-1·min^-1 (P＜0.01), recovery index in three groups were 10.8±4.2min,14.6±4.8min and16.2±5.3min (P＜0.01), Conclusions It is suggested that 1.0% sevoflurane and equipotantisoflurane can potentiate the muscular relaxation action of rocuronium.but the different ofpotentiated effect between the two is not significant.