Preventive effect of ondansetron on postoperative nausea and vomiting from continuous tramadol analgesia in cesarean patients

Objective To explore the preventive effect of ondansetron administered with different regimen on postoperative nausea and vomiting from continuous tramadol analgesia in cesarean patients. Methods A total of 80 women scheduled for elective cesarean section under combined spinal-epidural anesthesia were randomly divided into four groups with 20 cases each. 8 mg of ondansetron added into tramadol PCIA pump in group A; 8 mg of ondansetron injected i.v. after delivery of the fetus group B; 4 mg of ondansetron i.v. injection plus 4 mg added into the tramadol PCIA pump group C; group D received 4 m1of normal saline after delivery of the fetus. All patients received post-operative pain control with tramadol intravenous PCA. The nausea and vomit and visual analogue pain scale were recorded at 1, 6, 8, 12 and 24 h after operation. Results No significant difference was observed in the pain scales among the four groups. The assessment of nausea and vomiting showed that scorings in the group D was higher than groups A, B and C(P0.01), and in the group C that was lower than the groups A and B (P0.05), while no difference between the groups A and B. In the groups of A and B, VAS of pain scorings at 6 h after operation were higher than that at 12 and 24 h after operation points (P0.05).Conclusion Ondansetron can prevent the incidence of nausea and vomiting during tramadol analgesia, and it would be better when it was given by combining 4 mg i.v. injection after delivery of the fetus and 4 mg into the PCIA pump of trmadol.