Ramosetron versus ondansetron for postoperative nausea and vomiting in strabismus surgery patients

Postoperative nausea and vomiting (PONV) is one of the most common adverse outcomes after strabismus surgery. The primary outcome of this prospective, randomized, double-blind study was to compare the incidences of nausea or vomiting, and patient satisfaction of ondansetron and ramosetron after strabismus surgery under general anesthesia. The secondary outcome was to investigate whether the number of involved extraocular muscles (EOMs) in strabismus surgery was related to PONV. One hundred and five patients (aged 18-60 years) undergoing strabismus surgery were allocated randomly to one of the three groups: placebo, ondansetron, or ramosetron. Patients received 2 ml placebo, 4 mg ondansetron, or 0.3 mg ramosetron at the end of surgery. Each of the three groups was subdivided into two subgroups according to the number of EOMs involved in the surgery: subgroup S, single-muscle correction; subgroup M, multiple-muscle correction. The incidences of nausea or vomiting, and patient satisfaction at 2, 24 and 48 h after surgery were analyzed as primary outcome. With regard to subgroups S and M in the placebo, ondansetron and ramosetron groups, incidences of nausea or vomiting, and patient satisfaction at 2, 24 and 48 h after surgery were analyzed as seconadary outcome. The incidence of nausea was significantly lower in the ramosetron group at 2 h (9.4 %) than in the placebo (45.2 %) and ondansetron (34.7 %) groups (P