The effects of two anesthetic regimens on energy metabolism and oxygen cost of breathing / 中华麻醉学杂志

ABSTRACT

Objective To compare the effects of combined general-epidural anesthesia (CGEA) and general anesthesia (GA) on energy metabolism and oxygen cost of breathing.Methods Forty patients (25 male, 15 female) aged 42-61 yr weighing 42-75 kg scheduled for elective upper abdominal surgery were randomly divided into 2 groups : group CGEA (Ⅰ, n = 20) and group GA (Ⅱ, n = 20) . The patients were premedicated with midazolam 0.05 mg?kg-1 and scopolamine 0.3 mg i.m. . In groupⅠepidural catheter was placed at T9-10 A. test dose of 4ml of 2 % lidocaine was given. When the height of block was confirmed general anesthesia was started. In both groups anesthesia was induced with etomidate 0.3 mg?kg-1 , fentanyl 8 ?g?kg-1 and tracheal intubation was facilitated with atracurium 0.8 mg?kg-1 . Anesthesia was maintained with propofol in both group and intermittent epidural lidocaine in CGEA group and intermittent i. v. boluses of fentanyl in GA group. Muscle relaxation was maintained with atracurium infusion at 8 ?g?kg-1 ? min-1 during operation. Oxygen consumption ( VO2 ), CO2 production (VCO2 ) , energy expenditure ( EE) and respiratory quotient (RQ) were measured before anesthesia, during and after operation using indirect calorimetry (Datex, Deltatrac MBM-200) . Postoperative oxygen cost of breathing (OCB) was calculated during spontaneous breathing and controlled ventilation. Results VO2 , VCO2 , EE were significantly lower and RQ was significantly higher during operation than those before anesthesia in both groups (P