Effect of preoperative clove oil gargle on postoperative sore throat in adults after surgery: A randomized placebo-controlled blinded study

Postoperative sore throat (POST) is common after surgery. The objective of this study was to evaluate the effect of preoperative clove oil gargle on POST. Single centre, randomized, placebo-controlled, blinded study. Tertiary care academic hospital. Adults (18–65 years), of either gender, in ASA physical status I & II, undergoing surgeries lasting <3 h. Patients received a preoperative clove oil (0.5 mL in 20 mL tap water) or tap water (20 mL) gargle for 30 s, 15 min before induction of anesthesia. Primary objective was to evaluate the incidence of POST at 6 h. Secondary objectives were to evaluate the incidence of POST at 0 h, 30 min, 1 h, 2 h, and 24 h, and the severity of POST at all time points. POST was graded as 0 = no POST; 1 = mild POST (symptoms less than common cold); 2 = moderate POST (symptoms of common cold); and 3 = severe POST (more than common cold with throat pain and hoarseness of voice). Grades 2 & 3 POST were considered clinically significant. 134 patients completed the study (67 in each group). The incidence of POST at 6 h was significantly less in patients receiving clove oil gargle (26.9% vs 50.7%; P = 0.0049; RR = 0.53; 95% CI = 0.3 to 0.8); and also, at 2 h (13.4% vs 28.4%; P = 0.0334; RR 0.47; 95% CI 0.2 to 0.9). There was a significant difference in the proportion of patients with clinically significant POST at 24 h (clove oil vs tap water; 4.5% vs 16.4%; P = 0.0249; RR 0.23; 95% CI 0.08 to 0.9). The incidence or severity of POST was not different at other time points. Preoperative clove oil gargle resulted in reduced POST in patients following tracheal intubation vs placebo without any detectable adverse effect.