The Effects Of Different Doses Of Fentanyl On BIS And Hemodynamics During Anesthetic Induction

Objective To investigate the effects of different doses of fengtanyl on bispectral index((BIS) and hemodynamics during anesthetic induction.Methods Sixty patients under general anesthesia undergoing elective surgery were randomly allocated to three groups with 20 patients in each group according the dose of fentanyl,ASA I or II.The dose of fentanyl was 3 ug/kg in group F3,4 ug/kg in group F4 and 5 ug/kg in group F5. Every patient was premedicated with intramuscular scopolamine 0.3 mg and phenobarbital 0.1 g. Then connected BIS monitoring,and the line of SpO2, HR,ECG with each patient, and monitoring ABP.After the patient was quiet for five minutes, anesthesia was induced with midazolam 0.08 mg/kg,fentanyl and vecuronium 0.12 mg/kg.The oxygen flow were 5 L/min.Vecuronium (0.12 mg/kg) was injected when BIS reduced to 75. Tracheal intubation was begun until the BIS fell to 55 below;if not,profol was injected to reach the target. BIS, SAP, DBP,MAP, HR, were monitored continuously before anesthetic induction(To),before profol injected(to),before and after intubation(T1,T2), after intubation 2 min(T3),5 min(T4),8 min(T5),and the number of patients profol injected and the mean dose of one in each group were recorded.Results No significant difference were found among three groups before induction of anesthesia (P>0.05). After anesthetic induction,BIS of three groups was very significantly lower than before (P<0.01),and it was significantly higher after intubation than before intubation (P<0.05),but there was no significant changes among the three groups before intubation (P>0.05).Before profol injected, BIS of group F5 was lower than other groups (P<0.05),and the number of group F5 profol injected and the mean dose was very significantly less than other groups (P<0.01).SBP, DBP, MAP of each group reached the lowest level after anesthetic induction,and after tracheal intubation they were go higher,and they increased significantly greater in group F3 than other groups (P<0.05).After anesthetic induction,HR of group F5 was lower than other groups (P<0.05),and after intubation,significant difference among three groups was found (P<0.05).Conclusion The larger dose of fentanyl can get lower BIS and stable hemodynamics during anesthetic induction, but after tracheal intubation,the BIS and hemodynamics will be higher.