Natural killer cell activity in patients undergoing upper abdominal surgery: relationship to the endocrine stress response.

Natural killer (NK) cell activity and the endocrine response during and after parietal cell vagotomy were studied in two groups of patients receiving either epidural analgesia extending from S5 to Th4 + general anaesthesia (Group I), or general anaesthesia (Group II). NK cell activity of unseparated mononuclear cells in peripheral blood was measured against K-562 target cells in a 51Cr-release assay. NK cell activity increased in the same way in both groups in relation to premedication, anaesthesia and surgery (P less than 0.01). Postoperatively, the activity fell significantly on the first day (P less than 0.01), but returned to preoperative levels on day 3 (Group I) and day 5 (Group II). The endocrine response measured, except for adrenaline and prolactin, differed between Group I and II. In Group I, plasma noradrenaline and serum cortisol increased insignificantly throughout the observed period--compared to the preoperative level--whereas a significant increase in both hormones was found in Group II during surgery and in the postoperative period. A significant increase in plasma adrenaline and serum prolactin was found in both groups during anaesthesia and surgery. The findings indicate that NK cell activity during upper abdominal surgery is modified in almost the same way during two different anaesthetic techniques, one of which partly seemed to block the endocrine surgical stress response. The fluctuations in NK cell activity were not correlated to the changes measured in hormone concentrations.