Effect of general anaesthesia and surgery on neutrophil function

The effects of general anaesthesia and surgical trauma on neutrophil function were studied in 60 female ASA 1 and 2 patients undergoing anaesthesia for gynaecological surgery. Patients were divided into three groups depending on the degree of trauma and duration of surgery. Group 1 (n = 15) were patients for dilatation and curettage (minor surgical trauma) and were given 2% halothane. Group 2 (n = 30) had laparoscopic surgery (moderate surgical trauma) and received either 0.5% halothane or 1% enflurane. Group 3 (n = 15) were those having hysterectomy (major surgical trauma) and received 0.5% halothane for a longer duration. Venous samples were taken 30 min before anaesthesia (control value), 10 min after induction of anaesthesia, 10 min after the start of surgery, 30 min after the end of anaesthesia and 24 h later. Phagocytic index, nitroblue tetrazolium reduction test, total leucocyte count, and differential leucocyte counts were performed on each sample. Data were analysed by paired t-test to compare findings in the same patient and by unpaired t-test for differences between groups. Anaesthesia with halothane 0.5% to 2% caused a dose-related depressant effect on leucocyte function which reversed. Enflurane 1% on the other hand caused significantly greater depression of leucocyte function compared with 0.5% halothane which persisted during the recovery period and recovered on the first postoperative day. Total leucocyte counts also showed a fivefold increase in the major surgery groups.