A Comparative Study of Intrathecal Fentanyl and Intravenous Ondansetron for Prevention of Intraoperative Nausea and Vomiting During Cesarean Delivery under Spinal Anesthesia

Context: Nausea and vomiting is very common problem encountered during cesarean section. Aim: To compare the effects of intrathecal fentanyl and intravenous ondansetron in the prevention of intraoperative and post-operative nausea and vomiting during cesarean section under spinal anesthesia. Methods: This is a prospective comparative study conducted in a tertiary care teaching hospital in Nepal. Patients undergoing cesarean section were divided in two groups. Group 1 received intrathecal fentanyl and group 2 received intravenous ondansetron. Incidence of nausea and vomiting, mean arterial pressure, heart rate, oxygen saturation was recorded during eight different surgical steps of cesareans section. Pain was evaluated using numeric rating scale score. Results: Hundred and nine cases (53 in Group 1 and 56 in Group 2) undergoing cesarean section under subarachnoid block were studied. At eight specific intervals during surgery, a blinded observer questioned patients about nausea (1 nausea, 0 no nausea), observed for presence of vomiting (1 vomiting, 0 no vomiting), and recorded a pain score (0–10, 0 no pain, 10 worst unimaginable pain) using numeric rating scale score. Incidence of nausea in group 1was 16.98% in comparison to 3.57% with group 2 whereas incidence of vomiting was not significant among both groups. 49.05% vs 58.92% from group 1 and 2 respectively required intervention for hypotension and were treated with IV ephedrine. Statistically significant use of ephedrine was found during stage 6, two cases from group 1 and 10 cases from group 2 (p<0.05).. Conclusion: The incidence of nausea and vomiting was lower in the ondansetron group. Incidence of nausea during 6th stage of the study was also less in ondansetron group in comparison to fentanyl group making it superior for prevention of intraoperative nausea and vomiting.