The Effects Of Anesthesia Induction With Propofol Or Sevoflurane On The Onset Of Vecuronium

Objective To compare the induction quality of intravenous propofol with inhalational sevoflurane and to investigate their effects on the onset time of vecuronium.Methods Ninty ASA I—II patients, aged from 18 to 65 years, undergoing selective surgery with general anesthesia were randomized into three groups,group P₁,P₂ and S.Group P₁:intravenous induction with 1mg/kg propofol,group P₂: intravenous induction with 1.5mg/kg propofol, group S: inhalation of 8% sevoflurane in vital capacity respiration. All patients received inravenous fentanyl 4μg/kg immediately before induction.Excluded criterion:patients with severe cardiovascular,pulmonary ,hepatic and renal dysfunctions preoperatively;with neuromuscular disorders preoperatively;or with morbid oberity.Mechanomyography of the adductor pollicis muscle with single twitch(ST;0.1 Hz) stimulation was used to monitor neuromuscular function during anesthesia induction. After the paients lost consciousness,a continuous 0.1 Hz single stimulus with 0.2ms square wave and current of 50mA was delivered to the ulnar nerve at the wrist . The evoked response of the adductor pollicis muscle was recorded. When the twitch response was stabilized vecuronium 0.1mg/kg was administered. Time to loss of eyelash reflex,hemodynamic changes,onset time of vecuronium and condition of tracheal intubation were recorded.Results The time to loss of eyelash reflex in group S(54.40±15.77)s and group P₂(61.92±11.96)s was significantly shorter than that in group P₁(90.76±22.52)s(P<0.01).There was no difference between those in group P₂ and group S.The onset time of vecuronium in group S(110.40±23.10)s was significantly shorter than that in group P₁(133.42±26.53)s and that in group P₂(129.17±30.48)s(P<0.01).The tracheal intubation condition was similar in three groups. The induction depressed the DBP in group P₂ obviously (P<0.05).Tracheal intubation caused less stress response in group S than in group P₁ and P₂(P<0.01).Conclusion Sevoflurane induction had a stable circulation condition, and can also accelerate onset time of vecuronium significantly.