Postoperative pain and analgesic requirements after anesthesia with sevoflurane, desflurane or propofol.

BACKGROUND: General anesthetics may have nociceptive actions that affect postoperative pain. In studies evaluating postoperative pain, the effect of general anesthetics on analgesic requirements has not been considered except for one recent study suggesting that propofol anesthesia provides better analgesia after surgery than isoflurane.

METHODS: In this prospective, blind, randomized trial we recorded postoperative analgesic requirements (mg of morphine) and pain scores (visual analog scale in mm) 2, 4, 8, and 24 h postoperatively in patients undergoing abdominal hysterectomy or myomectomy under sevoflurane, desflurane or propofol anesthesia, titrated to maintain Bispectral Index values between 35 and 45. Pain scores were also recorded immediately after transfer to the postanesthesia care unit.

RESULTS: Cumulative morphine consumption did not differ among the three groups 2, 4, 8, or 24 h postoperatively (P = 0.50). The morphine consumed within 24 h postoperatively was 28 +/- 13.8 mg in the sevoflurane group, 25 +/- 11.7 mg in the desflurane group and 27 +/- 16.1 mg in the propofol group. The visual analog scale values at rest or after cough immediately after patient transport to the postanesthesia care unit and 2, 4, 8, and 24 h after surgery did not differ among the three groups (P = 0.40, 0.39, 0.50, 0.47, 0.06 at rest and P = 0.67, 0.45, 0.22, 0.26, 0.29 after cough respectively).

CONCLUSION: Morphine consumption and pain 24 h postoperatively did not differ among the sevoflurane, desflurane, and propofol groups.