Abstract
Background Postoperative nausea vomiting (PONV) is quite common among patients who underwent cesarean section under spinal anesthesia with intrathecal morphine (ITMO). Nalbuphine is a mu receptor antagonist and kappa receptor agonist, which may mitigate opioid-related side effects. We hypothesized that intravenous (IV) nalbuphine administration could possibly reduce the incidence of PONV. Methods In this randomized controlled trial, every patient receives spinal anesthesia with 0.2 mg of morphine for cesarean section. After umbilical cord clamping, patients in the study group received a single dose of 4 mg of IV nalbuphine. The primary outcome was the incidence of PONV in the first 24 hours. Secondary outcomes were the severity of nausea and vomiting, pain scores, incidence of pruritus and respiratory depression. Results One hundred and sixty-seven patients were included in the study. In 24 hours, incidence of nausea and vomiting in the nalbuphine group was lower than the placebo groups (23.81% and 42.17%). Ten percents of patients in the nalbuphine group had nausea and vomiting required treatment in the first 6 hours compared to 14.45% in the placebo group. Number of patients with pruritus and number of patients required rescue analgesic were also lower in nalbuphine group. No respiratory depression was observed in this study. Conclusion Four mg of IV nalbuphine could lower the incidence of PONV 24 hours after spinal anesthesia with 0.2 mg ITMO in patients underwent cesarean section. Incidence of other adverse effects also seem to be lower in the nalbuphine group.