Does the Anesthetic Technique Influence the Postoperative Analgesic Requirement?

Abstract

In order to determine the effect of two standard general anesthetic techniques on the postoperative analgesic requirement, 53 adults undergoing elective intra-abdominal surgery were randomly assigned to one of two anesthetic treatment groups according to an open parallel protocol design. One of the groups received an opioid-based anesthetic; the other group was administered an inhaled anesthetic. The postoperative analgesic requirement was quantified using a Baxter PCA device. The group receiving the opioid-based anesthetic required significantly less morphine in the recovery room (5.7 +/- 5.5 mg; mean +/- SD) compared with those receiving the conventional inhaled anesthetic (16.6 +/- 7.1 mg). During the first 8 hours after discharge from the recovery room there was a trend toward higher PCA morphine usage in the inhaled anesthetic group (25.6 +/- 15 mg vs. 18.6 +/- 13 mg); however, this difference was not statistically significant (p = 0.08). From 8 to 40 hours after surgery, the morphine usage was nonsignificantly higher in the opioid group (64 +/- 30 mg vs. 56 +/- 38 mg, p = 0.43). In conclusion, the general anesthetic technique used during an elective operation appeared to have little if any effect on the postoperative analgesic requirement after discharge from the recovery room.