The effect of preemptive intravenous morphine on postoperative analgesia and surgical stress response.
BACKGROUND
Although initial studies of preemptive analgesia showed that preoperative blockade with local anaesthetics or preoperative administration of systemic opioids was more effective in reducing postoperative pain than control conditions involving no treatment, the result of subsequent investigations comparing the effects of preoperative treatment with the same treatment initiated after surgery have produced inconsistent RESULTS. The reasons for the lack of consistency are not clear. Studies about the relationship of preemptive analgesia and both analgesic consumption and surgical stress response are limited. The purpose of this study was to evaluate the effect of preemptive intravenous morphine on both postoperative analgesic consumption and surgical stress response.


METHODS
Sixty patients, ASA I or II, aged 20-60, undergoing total abdominal hysterectomy plus bilateral salpingo-oopherectomy and double-blinded were randomly assigned to three groups of 20 patients. Group I (n=20) received 0.15 mg/kg of morphine following induction and placebo saline during peritoneal closure. Group II (n=20) received placebo saline following induction and 0.15 mg/kg of morphine during peritoneal closure. Group III (n=20) received placebo saline both during induction and peritoneal closure. Blood cortisol, glucose levels and leukocyte count were measured in the pre and postoperative period.


RESULTS
Postoperative total morphine consumption was significantly lower in group I compared with group III (p<0.001). In all groups, plasma cortisol levels increased significantly within 4 hours of surgery as compared to pre-op values (p<0.001). Plasma glucose also increased to a significantly higher level in all groups in the postoperative 30 min and 8 hours than in the pre-op values (p<0.001). Postoperative leukocytosis was observed in all groups and the leukocyte count was significantly greater during postoperative 24 h than pre-op values (p<0.001).


CONCLUSIONS
Preemptive morphine 0.15 mg/kg intravenous has decreased total morphine consumption but has failed to suppress the surgical stress response.
Kiliçkan
L
L
Department of Anaesthesiology and Resuscitation, Kocaeli University, Kocaeli, Turkey.
Toker
K
K
D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D001786:Blood Glucose / Q000032:analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007958:Leukocyte Count; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010149:Postoperative Pain / Q000188:drug therapy*; D013312:Stress, Physiological / Q000517:prevention & control*
D000701:Analgesics, Opioid; D001786:Blood Glucose; D009020:Morphine; D006854:Hydrocortisone