كاربرد روش تحليل دنباله اي مثلثي در ارزشيابي كارايي دوز كم دگزامتازون در كاهش لرز بعد از عمل

A Triangular Test to Assess the Efficacy of Low Dose Dexamethasone in Postoperative Shivering

Background and Objectives: Sequential clinical trials are becoming increasingly common in clinical reseach because they offer the ethical and economic advantages. These methods, allow repeated interim analyses to be performed throughout the trial recruitment period in order to allow the trial to be stopped as soon as sufficient information has been collected.There is an attempt in this study to perform sequential method for the first time in Iran. Material and Methods: This sequential randomized double blind triangular study was aimed at assessing the efficacy of dexamethasone (0.15mg/kg) on the incidence of postoperative shivering after non-cardiac surgeries (urologic, gynecologic, orthopedic and general). Results: This study was stopped after the seventh analysis (140 patients evaluated: 70 placebo and 70 dexamethasone) in favour of dexamethasone. Patients who had received dexamethasone had a significantly (p=).026 sequential analysis) lower incidence of postoperative shivering (11.4%) compared to the control group receiving placebo(28.6%). Conclusion: From methodologic viewpoint use of the triangular test leading to a 30% reduction in sample size and from the clinical point of view. Small doses of dexamethasone (0.15mg/kg) could effectively decrease the incidence of postoperative shivering.