RESUMEN
To determine the efficacy of single dose intravenous dexamethasone, administered one hour before surgery as prophylactic antiemetic. Single blinded, randomized, placebo controlled, interventional study. Usman Memorial Hospital Karachi, from January 2006 to June 2008. Patients admitted for elective general and gynecological surgery, having ASA I or II class were selected. They were randomly allocated to receive either 2 ml [8 mg] dexamethasone or 2 ml of normal saline, one hour before surgery. Surgery was performed under general anesthesia by a single anesthetist. Wound site was infiltrated with 20 ml of 0.5% bupivacaine. Injection ketorolac 30mg I/V was given prior to extubation and 30 mg I/V twice daily thereafter. Supplemental analgesia was provided with injection nalbuphine 10 mg diluted and supplemental anti emetic used was dimenhydrinate 50 mg I/V as required. Episodes of nausea and vomiting and drugs used were recorded on case files by nurse or doctor in the post-operative ward for 24 hours, who were blinded to pre-operative drug used. Any adverse events were also noted. Data was entered and analyzed using SPSS version 15. A total of sixty female patients were enrolled. They were divided into two groups, thirty in each [test group and placebo group]. Mean age of the patients was 42 years in both the groups. 61.7% patients had cholecystectomy, 15% had herniorrhaphy, 16.7% underwent abdominal hysterectomy and 6.6% had benign ovarian cystectomy. Duration of operation and anesthesia were comparable in both the groups. In the entire 24 hours period after surgery nausea occurred in 30% patients in test group A as compared to in placebo group B 77% [p=0.000], while vomiting in10% of test group versus 40% of placebo group [p=0.007]. Timed observations revealed that nausea occurred in 23% versus 70%, 10% versus 30% and 0% versus 6.7% in the first 6 hours, 6 - 12 hours and 12 - 24 post-operative hours respectively. Similarly vomiting occurred in 6.7% versus 40%, 0% versus 6.7% and 3.3% versus 3.3% patients. The number of episodes of nausea and vomiting were significantly reduced in the test group as was the need for supplemental antiemetics. Dexamethasone given as single I/V injection of 8 mg one hour before surgery is an effective drug for prophylaxis of post operative nausea and vomiting