RESUMO
The objective of this study was to compare the timing of administration of Ondansetron and Dexamethasone in terms of prevention of postoperative nausea and vomiting when given at induction verses thirty minutes before the end of prolong surgeries. Randomized control trial. The study was conducted in Main Operation Theatre of Combined Military Hospital Rawalpindi over a period of six months from 17 Apr 2009 to 16 Oct 2009. Cases were selected from OPDs, emergency and also by referral. Total 120 patients were included in this study [60 patients in each group] Group A patients received Ondansetron 4 milligrams and Dexamethasone 8 milligrams intravenous at induction and group B patients received Ondansetron 4 milligrams and Dexamethasone 8 milligrams thirty minutes before reversal of neuromuscular blockade at the end of surgery. Mean age was observed 41.7 +/- 3.7 and 39.9 +/- 1.9 in group-A and B, respectively. Comparison of pre-induction and 30 minutes before end of surgery at 0-6 hours reveal nausea and vomiting in 11 [18.3%] in group-A and in 3 [5.0%] patients of group-B. Results were statistically significant [p=0.022]. At 7-12 hours results were also statistically significant when comparison was made between group-A and B [p=0.051], while at 13-24 hours difference between two groups was statistically non-significant [p=0.314]. It is therefore established that administering a combination of Inj. Ondansetron 4mg with Inj. Dexamethasone 8mg, was more efficacious in reducing post-operative nausea and vomiting at 0-6 hours when administered 30 minutes before the completion of surgery