Advantages of intrathecal nalbuphine, compared with intrathecal morphine, after cesarean delivery: An evaluation of postoperative analgesia and adverse effects

We performed a prospective, randomized, double-blinded, multicenter study t o compare the analgesic efficacy and adverse effects of intrathecal nalbuph ine, at three different doses, and intrathecal morphine for postoperative p ain relief after cesarean deliveries. Ninety healthy patients at full term who were scheduled for elective cesarean delivery with spinal anesthesia we re enrolled in the study. They received 10 mg of hyperbaric bupivacaine 0.5 % with either morphine 0.2 mg (Group 1), nalbuphine 0.2 mg (Group 2), nalbu phine 0.8 mg (Group 3), or nalbuphine 1.6 mg (Group 4). Only patients in Gr oups 1 and 2 reported pain during surgery. Postoperative analgesia lasted s ignificantly longer in the morphine group, compared with the nalbuphine gro ups (P < 0.0001). In the nalbuphine groups, postoperative analgesia lasted longest with the 0.8-mg dose. The additional increase to 1.6 mg did not inc rease efficacy. The incidence of pruritus was significantly higher in Group 1 (11 of 22), compared with Group 2 (0 of 22, P < 0.0002), Group 3 (0 of 2 3, P < 0.0001), and Group 4 (3 of 20, P < 0.02). Postoperative nausea and v omiting were more frequent in Group 1 (5 of 22), compared with Group 2 (0 o f 22, P < 0.05), Group 3 (0 of 23, P < 0.05), and Group 4 (3 of 23, not sig nificant). There was no maternal or newborn respiratory depression. Neonata l conditions (Apgar scores and umbilical vein and artery blood gas values) were similar for all groups. This study suggests that intrathecal nalbuphin e 0.8 mg provides good intraoperative and early postoperative analgesia wit hout side effects. However, only morphine provides long-lasting analgesia.