Loop Target Controlled Inhalation Anesthesia In Obese Patients, The Clinical Application

Objective To study the feasibility of application of bispectral index(BIS) feedback in control of inhalation anesthesia in fat patients..Methods Forty patients were randomlized into control group(groupâ… ) andBIS feedback group(groupâ…¡)with 20 in each group.In groupâ… , anesthesia depth adjusting was based on MAP,HR and the reaction of operation stimulation.In groupâ…¡using BIS as the control variable, A closed-loop anesthesia system was built using a proportional-integral-differential incorporated with adaptive control algorithm,and a target-controlled infusion system as the control actuator,Closed-loop performance deal with changing of BIS both target and reality measure,and then according to the order which TCI-â… pump presetted pattern,It export new orders to TCI pump to adjust liquid of Isoflurane which reach respiratory circuit.Observe hemodynamic change in induction of anesthesia,placement of endobronchial tube,maintain of total anesthesia and convalescent.Record consciousness recovery time stopping inhalating Isoflurane(open eyes and extubate time),check patients have no awareness during operation.Results After induction of anesthesia,BIS count of two groups was significant different(P<0.01); during operation BIS count of patients had no significant difference (p>0.05).the incidence rate of BIS countover 60:groupâ… was 14.03%, groupâ…¡7.48%,the difference was significant(p<0.05),the incidence rate of BIS count low 40:groupâ… was 1.75%,groupâ…¡1.21%,the difference was no significant(p>0.05).the time of patients awaken in groupâ…¡was earlier than that in groupâ… at the end of operation(p<0.05).Aâ…¡patients had no awareness during operation.Conclusion It may be more reasonably with inhalation general anesthesia to apply BIS feedback controls of anesthesia depth on fat patients to prevent from awareness during operation,to decrease the doses of anesthetics and to accelerate consciousness recovery.