The Study On Strategy Of General Anesthesia Induction Of Sevoflurane

Objective: To investigate the patients with variety inhalation methed and inhalation concentration during sevoflurane induction of general anesthesia,According to the effect of circulation stability and loss of conciousness,To select the ideal methed of sevoflurane induction of general anesthesia.Methods: Forty five patients with ASAⅠ～Ⅱscheduled for elective operations,undergoing endotracheal intubation,All the patients were no allergic,no disease of circulatory and respiratory system,no disease of hepatic and renal system.The patients were randomly divided into three groups,every group included fifteen patients.Vital capacity breathing(group A);Tidal capacity breathing(group B);gradually increased concentration( group C).All the patients not used preanaesthetic medication,going into operation room and intravenous cannula was placed.Electrocardiogrphy were monitored during whole procedures.Quietly lain ten minutes(T1),we measured and recorded systotic blood pressure(SBP),diastotic blood pressure(DBP),mean arterial pressure(MBP),heart rate(HR),pulse oximetry value as baseline.Group A:The patients inhaled 8% sevoflurane and 4% oxygen with vital capacity breathing pattern;Group B:The patients inhaled 8% sevoflurane and 4% oxygen with tidel capacity breathing pattern;Group C:Beginning of the induction,The patients inhaled 3% sevoflurane and 4% oxygen with tidel capacity breathing pattern,then increase 1% sevoflurane concentration every 20 seconds.At loss of eyelash reflex(T2),all of the patients slowly injected 3μg/kg fentanyl and 0.1mg/kg vecuronium through intravenous.At the same time,decreased sevoflurane concentration to anes- thesia maintain concentration,assisted respiration.After 3 minutes,orotra- cheal intubation.During induction,we recored systotic blood pressure(SBP), diastotic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR),pulse oximetry value at loss of eyelash reflex(T2), before intubation (T3), after intubation 1 minutes(T4), after intubation 3 minutes(T5), after intubation 5 minutes(T6).and recored the time of loss of eyelash reflex.The incidence of adverse events as limds movement, laryngospasm,excitement, coughing,muscle rigidity,nausea and vomiting,arrhythmias during theinduc- tion were recored too.SPSS11.5 software was used as statistical method. ANOVA was used in the study groups;Quantitative data were analysed using Pearson's X2-test.Results: Before induction, at T1 point,all mean values are normal range.Between groups. there were no significance(p>0.05); After induction, all values compared in the same group, results: Group A:DBP values decreased than T1 in the other points, T3(p<0.01)decreased greatly significant;T4, T5, T6 (p<0.05)decreased significant; SBP values decreased than T1 in the other points, T3(p<0.01)decreased greatly significant; T5, T6(p<0.05)decreaed significant; MAP values decreased than T1 in the other points,T3 (p<0.01) decreased greatly significant; T4,T5,T6(p<0.05) decreased significant; comparison with T1,HR decreased in all the time, T3 decreased signifcant(p< 0.05),the others was no significant(p>0.05). Group B:DBP values decreased than T1 in the other points,T3, T6 decreased greatly significant(p<0.01);T5 decreased significant (p<0.05) , T3 decreased significant then T4 (p<0.05) SBP values decreased than T1 in the other points,T3,T6 decreased greatly signifycant(p<0.01);T5 decreased significant(p<0.05);T3 decreased significant then T4(p<0.05);MAP values decreased than T1 in the other points,T3 decreased greatly significant (p<0.01);T5,T6 decreased significant(p<0.05); T3 decreased significant then T4(p<0.05);Comparison with T1,HR increased slightly at T2 point, the others decreased,but no significance(p>0.05). Group C: DBP values decreased than T1 in the other points, T3(p<0.01) decreased greatly significant;T4,T5,T6(p<0.05)decreased significant; SBP value decreased than T1 in the other points,T3,T5,T6(p<0.01)decreased greatly significant; T4(p<0.05)decreased significant; MAP values decreased than T1 in the other points,T3(p<0.01)decreased greatly significant; T4,T5,T6(p<0.05) decreased signifycant;Comparison with T1, HR increased slightly at T2 point, T3 decreased greatly, T3 decreased significant than T2(p<0.05),the others was no significance(p>0.05). Comparison with groups:All the values were no significance.After induction, pulse oximetry values increased than baseline;Between groups, the time of loss of eyelash reflex were significant (p<0.05),group C was greatly significant than group A(p<0.01). The incidence of adverse events:At induction,two patients has limds movement and one patient has muscle rigidity in group A; one patient has limds movement and one patient has coughing;one patient has limds movement , one patient has laryngospasm and one patient has nausea in group C.Conclusion: Inhalation induction of anaesthesia with sevoflurane with the three techniques tested is safe,reliable and well accepted by the patients;The vital capacity inhalation induction group with sevoflurane was the fastest methed.Comparison with two groups,the effect of hemodynamic changes was no significance,it was not increased the ratio of the incidence of adverse events.So the vital capacity breathing methed is the ideal methed of sevoflurane induction of general anaesthesia.