A Feedback Target-controlled Infusion(TCI) Of Propofol By Bispectral Index And Auditory Evoked Potential Index In The Elderly

【Objective】 To study the feasibility of bispectral index(BIS) and auditory evoked potential index(AEPI) modulating the depth of anesthesia in the elderly patients during the target controlled-infusion(TCI) of propofol general anesthesia.【Methods】Forty five ASA physical status of Ⅰ-Ⅱ patients with normal hearing undergoings selective surgery were divided into three groups with 15 cases each:The patients in the elderly groups (group Ⅰand groupⅢ ) were 65-80years old, in the younger 20-65 years old (group Ⅱ). The anesthesia was induced by fentanyl,propofol,suxamethonium and maintained with TCI in all patients. The target concentration o f propofol was modulated by AEPI and BIS in groupⅠand Ⅱ ,and by hemodynamics in group Ⅲ.the changes of HR ,SBP, DBP, MAP, AEPI and BIS were recorded at the eight times during anesthesia. Total dose of propofol, duration of the anaesthesia , the emergence time after discontinuation, the perioperative awareness were recorded,too. 【Results】 In all patients, SBP, DBP and MAP significantly decreased at intubation(p<0.05). At 5min after intubation,the hemodynamics was significantly lower than the baseline in group Ⅰ(p<0.05), but was higher than after intubation . The hemodynamics at discontinuation was significantly higher than at exploration (p<0.05) in group Ⅰ; While the changes was not significantly different in group Ⅱ. In group Ⅲ, the hemodynamics at incision skin was significantly higher than after intubation (p<0.05) .The hemodynamics at discontinuation was significantly higher than at exploration (p<0.05) in group Ⅲ.BIS and AEPI were not significantly different in three group. There were significant correlation between BIS and AEPI (r=0.780,0.781,0.752) (p<0.01). The standardized unit dose of propofol was 106.43μg?kg-1?Min-1 in group Ⅰ, 123.11μg?kg-1?Min-1 in group Ⅱ, 116.76μg?kg-1?Min-1 in group Ⅲ. The standardized unit dose of groupⅠ was significantly lower than that of groupⅡ and group Ⅲ(P<0.05).There wasn't awareness in groupⅠand group Ⅱ, There were two awarenesses in group Ⅲ. Time of emergence in the group Ⅲ was significantly longer than that of group Ⅱ and group Ⅲ(P<0.01). 【Conclussion】 Anesthesia with target controlled-infusion propofol modulated by AEPI and BIS in the elderly is feasible with the advantages of keeping stable hemodynamics, avoiding prolonged emergence.There were consistent between AEPI and BIS.