The Research On MAC And MACawake Of Sevoflurane Under BIS Monitoring In Elderly Patients Undergoing Abdominal Surgery

Objective: To investigate MAC and MACawake of sevoflurane in elderly patients undergoing abdominalsurgery when the depth of anesthesia was maintained at BIS50±5and to provide a more ideal anedthesiamethod.Methods: Sixty ASA I–II elderly patients scheduled to undergo abdominal surgeries were devided into twogroups randomly:Sevoflurane group(S group)and propofol group(P group).Then connected the agedpatients with electrocardiogram(ECG),BIS monitoring, the line of radial artery catheterization,of directarterial blood pressure,and pulse oxygen saturation(SpO2).Three minutes after the patient Quiet,anesthesiawas induced with Midazolam0.05mg/kg,fentany2.0ug/kg,group S induced with sevoflurane andsevofluran inhaled for maintenance,group P induced with propofo(1mg/kg).When BIS reduced to75injected Attacurium(0.5mg/kg),Until the BIS fell to50below,tracheal intubation were began.1-2minbefore surgical incision,each group added fentany(1~2ug/kg),the concentration of Sevoflurane inhalation ingroup S,and target-controlled of propofol concencentration in group P.Recorded the change of MBP,HRbefore anesthetic induction,before and after inbutation,5min after inbutation,skin incision,Surgicalexploration,skin closure,Tracheal Extubation,excepting that S group record the IT%,ET%and MACawakeof Sevoflurane.Spontaneous breathing recovery time,call time to eye opening,extubation time wererecorded．Results:1. There were no significant difference among two groups before induction of anesthesia.Beforetracheal intubation,MBP,HR of the two groups reached the lowest level.MAP,HR in group P fellsignificantly than group S(P<0.05);when before induced,the MAP,HR in group P fell significantly thanwhen before anesthetic induction(P<0.05);there is no significance difference of MAP and HR compare T4with T8in the two groups (P>0.05).2. There is no significance difference of ET%compare T5withT7(P>0.05).Et%of sevoflurane in elderly patients undergoing abdominal surgery is1.94%.3. MACawakeis0.4%.4. Compared with group P,Spontaneous breathing recovery time,extubation time were significantlydecreased in group S(P<0.05).Conclusions:1. Et%of sevoflurane in elderly patients undergoing abdominal surgery is1.94%,MAC is1.49%; MACawake is0.4%.2. Using sevoflurane in elderly patients undergoing abdominal surgeryinduced rapid,blood pressure drop is small,intraoperative hemodynamic stable,without complications.