RESUMEN
BACKGROUND: Spinal morphine provides the optimal treatment for post-cesarean analgesia, despite frequent nausea and vomiting. We investigated the incidence of nausea and vomiting 24 hours after cesarean delivery in women receiving intrathecal morphine 100 µcg and intravenous prophylactic dexamethasone and ondansetron. METHODS: In a prospective, observational, Institutional Review Board (IRB) approved study of women undergoing cesarean delivery according to a standardized anesthetic protocol, the subjects were approached preoperatively and underwent standardized interviews regarding prior anesthesia experience and history of postoperative nausea and vomiting. In the post anesthesia care unit and 24 hours postoperatively, the women were interviewed regarding the incidence of nausea and vomiting, Women with and without nausea at 24 hours were compared for potential associated risk factors. RESULTS: Among 201 women recruited, 29 (14.5%) had nausea and 7 (3.5%) vomited in the postoperative care unit. During the first 24 hours, 36 (17.9%) had experienced nausea and 19 (9.5%) had vomited when interviewed at the 24-hours postoperatively. Women who had nausea 24 hours postoperatively were more likely to have nausea in the post anesthesia care unit than women without nausea during 24 hours after cesarean delivery (41.7% versus 1.2%, p<0.001). We did not find preoperative risk factors for postoperative nausea and vomiting. CONCLUSIONS: We report that almost 20% of the women managed with prophylactic dual therapy of ondansetron and dexamethasone had nausea during the 24 hours after administration of low dose intrathecal morphine. Our findings suggested that women who experience nausea or vomiting in the immediate postoperative period are at increased risk of nausea and vomiting in the 24-hour postoperative period.