Changes of the erythrocyte glucose metabolism and oxidative stress responses in patients undergoing esophageal surgery under different anesthetic techniques

Thirty-two ASA I - II patients aged 45-71 yrs weighing 55-70 kg were randomly allocated to one of two groups with 16 patients in each group : group I received isoflurane inhalation for maintenance of anesthesia and group II isoflurane inhalation combined with epidural block. Patients with endocrine and glucose metabolism-related diseases were excluded. The patients were premedicated with intramuscular phenobarbital 0.1 g and atropine 0.5 mg. Anesthesia was induced with intravenous midazolam 0.1mg·kg~(-1), propofol 1.0-1.5mg·kg~(-1) , fentanyl 0.1-0.15 mg, droperidol 1-2 mg and vecuronium 0.1mg·kg~(-1) in both groups. The patients were mechanically ventilated (V_(T) 8-10 ml·kg~(-1), RR 10-12 bpm) after tracheal intubation. Anesthesia was maintained with isoflurane inhalation at 1.2-1.6 MAC in group I or isoflurane inhalation (0.6-0.8 MAC) combined with epidural block (T_(9-10)) with 1% lidocaine in group II supplemented with fentanyl 5-10#mu#g·kg~(-1) and droperidol 0.1-0.2 mg-kg~(-1) in divided doses and vecuronium infusion at 1 -2 #mu#·kg·min~(-1). Venous blood samples were obtained before anesthesia (baseline, T_(0) ) , 90 min after skinincision (T_(1) ) , 60 min after surgery (T_(2) ) and on the 1st and 2nd postoperative days (T_(3) , T_(4) ) for determination of erythrocyte AR, PFK and G-6PD activities and plasma glucose, MDA and GSH levels.In group I plasma MDA level and AR and G-6PD activities in erythrocyte were significantly increased, while plasma GSH level and PFK activity in erythrocyte were significantly decreased on the 1st postoperative day compared to the baseline values before anesthesia (T_(0)) (P 0.05). Isoflurane inhalation combined with epidural block can effectively attenuate the effects of surgical trauma on glucose metabolism in the etythrocytc and the oxidative stress responses of the body.