[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--7. Effects on natural killer cell activity].

Twenty four patients who underwent ophthalmic surgery were studied to evaluate activities of natural killer (NK) cells during and following total intravenous anesthesia with droperidol, fentanyl and ketamine. They were divided into three equal groups according to anesthetic methods employed. In enflurane group, anesthesia was induced with thiopental 5 mg.kg-1 and succinylcholine 1 mg.kg-1, and maintained with 1-2% enflurane, nitrous oxide (50%) and oxygen (50%). In original NLA group, anesthesia was induced as above and maintained with droperidol 0.15 mg.kg-1, fentanyl 5-10 micrograms.kg-1, nitrous oxide (70%) and oxygen (30%). The patients of total intravenous anesthesia group received droperidol 0.15 mg.kg-1, ketamine 2 mg.kg-1 and succinyl-choline 1 mg.kg-1 for induction of anesthesia, and then were given fentanyl 5-15 micrograms.kg-1, ketamine 2 mg.kg-1.hr-1 and oxygen (30%) for the maintenance of anesthesia. Vecuronium was given to every patient of the three groups for intraoperative muscle relaxation. Hartmann's solution was used at a speed of 5 ml.kg-1.hr-1. Peripheral venous blood 10 ml was drawn on six occasions during and after the surgery for the measurement of NK cell activities and endocrine response as judged by plasma catecholamine and cortisol levels. NK cell activities decreased significantly on the first post-operative day in enflurane group, but no significant differences were found among three groups in NK cell activities. The data suggest that inhaled anesthetics should not be easily employed for patients with depressed immune response, malignant disease and prolonged surgery.