A Comparative Study between Ondansetron and Dexamethasone as Antiemetic during Elective Caesarean Section done Under Spinal Anaesthesia

Background Intra operative nausea and vomiting are frequently seen in parturients during caesarean section (CS) under regional anaesthesia. It is a major problem, not only for the patient but for the surgeon and the anaesthesiologist as well. Objective To compare the antiemetic efficacy of Ondansetron and Dexamethasone combination with that of the single use of each agent to decrease the incidence of post-delivery intra-operative nausea and vomiting (IONV) during CS under spinal anesthesia. Method A randomized, prospective, double blind study was performed on total 90 ASA I & II full term parturients undergoing elective CS under spinal anaesthesia. Group A (n=30) received 4mg Ondansetron, Group B (n=30) received 8mg Dexamethasone, Group C (n=30) received 4mg Ondansetron plus 8mg Dexamethasone intravenously within 1-2 minutes after the umbilical cord was clamped. Frequency of post-delivery IONV episodes was recorded. Results No statistically significant difference was seen between the groups in terms of baseline characteristics and intra-operative managements. In Group A 22 (73.33 %) patients, in Group B 21 (70 %) patients and in Group C 19 (63.33 %) patients were free of emetic symptoms, Frequency of intra-operative nausea, retching and vomiting experiences were similar between the groups (pgreater than0.05). Conclusion Single dose 4 mg Ondansetron or 8mg Dexamethasone given intravenously are both effective agents for the control of post-delivery IONV in caesarean section under spinal anaesthesia, however, the combined use of these agents is no better than both used alone neither in terms of efficacy nor side effect profile.