Addition of noradrenaline to intrathecal morphine augments the postoperative suppression of natural killer cell activity.
OBJECTIVE
Intrathecal administration of morphine has been shown to suppress natural killer (NK) cell activity. We tested the hypothesis that combined administration of morphine and noradrenaline would further modify NK cell activity in patients undergoing hysterectomy.


METHODS
Thirty female patients were randomly divided into three groups of ten patients each. Groups MN and M received intrathecal morphine (0.5 mg) dissolved in 5 ml of physiological saline with and without 5 micro g noradrenaline, respectively. Group C received saline alone. After the intrathecal administration, general anesthesia was induced. Blood samples were withdrawn before and 2 h after surgery and on postoperative days 1, 2, and 7 to determine the NK cell activity, the ratio of T-helper/inducer cells (CD4) to T-suppressor/cytotoxic cells (CD8), the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8), and the plasma concentrations of catecholamines and cortisol.


RESULTS
NK cell activity decreased on postoperative day 1 in groups MN (12.0 +/- 2.7%) and M (25.4 +/- 9.6%) compared with their respective baseline levels. In group MN, NK cell activity remained lower (23.7 +/- 8.0%) on postoperative day 2 than the baseline value before surgery.


CONCLUSIONS
Intrathecal administration of morphine causes a decrease in NK cell activity, and its combined use with noradrenaline prolongs the suppression of NK cell activity.
Department of Anaesthesiology, Kanto Rohsai Hospital, 2035 Kizukisumiyoshi-cho, Nakahara-ku, 211-8510 Kawasaki, Japan.
Tetsuya
T
Yokota
Kiyoshi
K
Uehara
Yukiko
Y
Nomoto
D000328:Adult; D000775:Anesthesia, Spinal; D016516:CD4-CD8 Ratio; D004357:Drug Synergism; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007278:Injections, Spinal; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D010149:Postoperative Pain / Q000188:drug therapy*
D007166:Immunosuppressive Agents; D009020:Morphine; D009638:Norepinephrine