Comparison of the Effect of Ondansetrone - Dexamethasone, Dexamethasone - Metoclopeamide and Ondansetron - Normal Saline in Decreasing Post Operative Nausa and Vomitting (PONV) after Middle Ear Surgery

The incidence of post-operative nausea and vomitting (PONV) is increased after middle ear surgery and it may complicate and interact with reconstruction after surgery, so prevention and treatment of these complications are necessary. The aim of this study was to evaluate the efficacy of anti-emetic combinations in decreasing the PONV after middle ear surgery.

This double blind clinical trial was carried out during 2007-2008 on 111 patients of 15-45 years old with ASA I-II who were candidates for elective middle ear surgery under general anesthesia. The patients were divided into three groups. Patients in the ON group received Ondansetrone 0.1mg/kg + Nacl 0.9% 2cc, OD group received Ondansetrone 0.1mg/kg + Dexamethasone 0.15mg/kg and MD group received Dexamethasone 0.15mg/kg+ Metoclopramide 0.15mg/kg intravenously just before the end of surgery. The patients were evaluated for nausea, vomiting, need of anti-emetic drugs and drug dosage in recovery, 1-6, 6-12 and 12-24 hours after operation and then all data were statistically analyzed by SPSS software, Chi-square, ANOVA and t- Test. P<0.05 was significant.

There were no significant differences among three groups in age and sex. The incidence of PONV among 3 groups was not significantly different during 24 hours after operation. (P=0.271) but the incidence of PONV in the first six hours was different among 3 groups (P=0.007) (ON: 8.1%, OD: 0%, MD: 21.6%). Also Metoclopramide consumption was significant between three groups.

This study showed that the need to anti-emetic drugs in first 6 hours was the least in OD group, but the difference in the incidence of PONV was not significant otherwise.