Effect of intravenous palonosetron on hypotension induced by spinal anesthesia for cesarean section: A randomized controlled trial.

Background: The aim of this study was to evaluate the impact of intravenous palonosetron compared to ondansetron on hypotension induced by spinal anesthesia in women undergoing cesarean section. Methods: Fifty-four women scheduled for elective cesarean section were, randomly allocated to ondansetron group (n = 27) or palonosetron group (n = 27). Ten minutes prior to the administration of spinal anesthesia, participants received an intravenous injection of either ondansetron or palonosetron. A prophylactic phenylephrine infusion was initiated immediately following the intrathecal administration of bupivacaine and fentanyl. The infusion rate was titrated to maintain adequate blood pressure until the time of fetal delivery. The primary outcome was total dose of phenylephrine administered. The secondary outcomes were nausea or vomiting, the need for rescue antiemetics, hypotension, bradycardia, and shivering. Complete response rate, defined as the absence of postoperative nausea and vomiting and no need for additional antiemetics, were assessed for up to 24 hours post-surgery. Results: No significant differences were observed in the total dose of phenylephrine used between the ondansetron and palonosetron groups (387.5 μg [interquartile range, 291.3–507.8 μg versus 428.0 μg [interquartile range, 305.0–507.0 μg], P = 0.42). Complete response rates also showed no significant differences between the groups both within two hours post-spinal anesthesia (88.9% in the ondansetron group versus 100% in the palonosetron group; P = 0.24) and at 24 hours post-surgery (81.5% in the ondansetron group versus 88.8% in the palonosetron group; P = 0.7). In addition, there was no difference in other secondary outcomes. Conclusion: Prophylactic administration of palonosetron did not demonstrate a superior effect over ondansetron in mitigating hemodynamic changes or reducing phenylephrine requirements in patients undergoing spinal anesthesia with bupivacaine and fentanyl for cesarean section. [ABSTRACT FROM AUTHOR]