Effect of different administration routes of ramosetron hydrochloride on postoperative nausea and vomiting induced by intravenous analgesia in cesarean patients

Objective To explore the preventive effect of ramosetron hydrochloride on postoperative nausea and vomiting (PONV) induced by intravenous fentanyl for analgesia in cesarean patients. Methods A total of 120 full-term women with singleton pregnancy (American Society of Anesthesiologists gradeⅠorⅡ) scheduled for cesarean section under epidural anesthesia were randomly divided into four groups (n=30). Ramosetron hydrochloride 0.3 mg was intravenously injected after delivery in intravenous group; ramosetron hydrochloride 0.3 mg was added into fentanyl patient-controlled intravenous analgesia (PCIA) pump in PCIA group; the combination of intravenous injection and PCIA of 0.3 mg ramosetron hydrochloride in joint group and ramosetron hydrochloride was not used in control group. All patients received postoperative pain management with intravenous fentanyl PCIA. Visual analogue scale (VAS) scores for pain were recorded at 1, 6, 12, 24 and 48 h after surgery and the incidence of PONV within 48 hours were evaluated. Results No significant differences in VAS pain scores were found not only at different time points in the same group but also at each time point among the four groups (all P0.05). The incidence rates of PONV in intravenous group, PCIA group, joint group and control group were 30.0% (9/30), 36.7% (11/30), 6.7% (2/30) and 63.3% (19/30), respectively. The incidence rate of PONV in control group was significantly higher than that in the other three groups (all P0.05). The incidence rate of PONV in joint group was significantly lower than that in intravenous group and PCIA group (both P0.05). Conclusion Ramosetron hydrochloride can effectively reduce the incidence rate of PONV induced by intravenous fentanyl for analgesia. The best route of administration may be intravenous injection of 0.3 mg ramosetron hydrochloride plus 0.3 mg ramosetron hydrochloride added into the fentanyl PCIA pump after delivery.