Feasibility Study Of Etomidate Used For Total Intravenous Anesthesia In Geriatric Patients Under The Guidance Of BIS

Objective: To evaluate the feasibility of etomidate used for TIVA under the guidance of BIS in geriatric patients undergoing elective abdominal operations.Methods: Forty ASAⅡorⅢpatients, aged 60～75 years, undergoing elective abdominal operations were randomized to 2 groups, including etomidate group(group E) and propofol group(group P), 20 patients in each group. The two groups received either TIVA with propofol or etomidate-midazolam-fentanyl-vecuronium. Anaesthesia was induced with etomidate 0.2～0.3mg/kg and was maintained with infusion of etomidate 5～20μg·kg^-1·min-1in Group E. Accordingly, anaesthesia was induced with propofol 1.5～2mg/kg and was miaintained with infusion of propofol 4～10mg·kg^-1·h-1in Group P. During the operation, remifentanil was infused with the speed of 0.15～0.3μg·kg^-1·min-1. Vital sign parameters involving SBP, DBP, MAP, SpO2 and HR were continuously recorded during the operation. The time from discontinuation of the anaesthetic to opening eyes on verbal command and extubation were recorded also. Blood samples were drawn before induction, at 30min after incision, at 8h and 24h after surgery. The level of serum cortisol was measured by radioimmunoassay.Results: Compared with group P, the hemodynamic status in group E after induction was more stable (P<0.05), but the heart rate in group E were higher than those in group P at extubation (P<0.05). The time from discontinuation of the anaesthetic to opening eyes on verbal command and extubation in group E were longer than those in group P(P<0.05). The level of serum cortisol at 30min after incision and 8h after surgery in group E were lower than those in group P(P<0.05). There was no significant difference in the concentration of serum cortisol between the two groups at 24h after operation (P>0.05). In group E, the concentration of serum cortisol at 30min after incision was lower than that before anaesthesia (P<0.05), and then increased to the preanesthetic level at 24h after surgery.Conclusion:1.Etomidate combined with remifentanil and vecuronium could be effectively used in geriatric patients undergoing elective abdominal operation.2.The effection of adrenal suppression is transient and reversible when etomidate was used for TIVA.