General anesthesia and surgery inhibited natural killer cell cytotoxicity in patients with cancer or benign disease undergoing upper abdominal surgery

In this study, effect of enflurane anesthesia combined with epidural analgesia on natural killer cell cytotoxicity (NKCC) was investigated in 20 patients. Patients were divided into two groups: the first group with adenocarcinoma of stomach (Group 1); the second with cholecystolithiasis (Group 2). Four samples were taken; 1) on arrival at operating room; 2) during anesthesia and 1 hour after skin incision; 3) on 1st postoperative day; and 4) on 4th or 5th postoperative day. NKCC was determined with a chromium release assay against K 562 cell. NKCC was already significantly higher before induction in Group 1 compared with Group 2 and normal value. In Group 1, NKCC decreased significantly compared with baseline during operation, but in group 2 NKCC was unchanged during operation. NKCC in group 2 was inhibited significantly less than Group 1 during 5 postoperative days, while NKCC was significantly inhibited postoperatively in both groups compared with the baseline. We conclude that enflurane anesthesia combined with epidural analgesia and surgery did not decrease NKCC below normal value during operation, but it was significantly inhibited during 5 postoperative days in both groups. There were differences in responses to stress of anesthesia and surgery between patients with and without cancer.