كارآزمايي آزمون مثلثي دوگانه در بررسي اثر گرماي موضعي بر گلودرد ناشي از لوله گذاري در ناحيه تراشه

The double triangular sequential test to assess the effect of local heat on postoperative sore throat after endotracheal intubation

Objective: Sore throat is a common complication after intubation. The objective of this study, from the clinical viewpoint, is the evaluation of the local heat on postoperative sore throat. Also this study, from the methodological viewpoint, is an attempt to introduce the ethical and economical advantages of sequential analysis that was used for the first time in Iran. Materials and Methods: In this clinical trial patients were randomly assigned to either experimental or control group. In the experimental group a small electrical blanket with the temperature of 40 C was used during the general anesthesia. The sequuntial double trianuglar test was used to analyse and monitor clinical trial. Results: This study was stopped after the forth analysis (80 patients evaluated: 40 with electrical blanket and 40 without it) in favor of electric blanket. Whereas the sample size required by the single-stage-design was 160. Conclusion: Our findings showed that local heat on the tracheal area could reduce the incidence of postoperative sore throat. Also, from methodological viewpoint, using the double triangular test leading to a 50% reduction in sample size, which is more effective from health economics viewpoint.