Comparison of prophylactic effect of topical Alchemilla vulgaris in glycerine versus that of dexamethasone on postoperative sore throat after tracheal intubation using a double-lumen endobronchial tube: a randomized controlled study

Background: Sore throat and hoarseness frequently occur following general anesthesia with tracheal intubation and are effectively reduced when dexamethasone is used prophylactically. Alchemilla vulgaris in glycerine (Neo Mucosal Activator®) suppresses inflammatory response, possibly relieving sore throat.Methods: We enrolled 94 patients (age ≥ 18 years) scheduled for thoracic surgery using double-lumen tube intubation. Before intubation, 0.2 mg/kg of dexamethasone was administered intravenously and 2 ml of normal saline was sprayed into the oropharyngeal cavity (Group D; n = 45), or 0.04 ml/kg normal saline was administered intravenously and 1 g of Neo Mucosal Activator® mixed with 1 ml of normal saline was sprayed into the oropharyngeal cavity (Group N; n = 43), in a double blind and prospectively randomized manner. Postoperative sore throat and hoarseness were recorded using a numeral rating scale and a 4-point scale to detect a change in voice quality following tracheal extubation (at 1, 6, and 24 h). The primary outcome was the incidence of sore throat at 24 h following surgery. The secondary outcomes were incidence and severity of sore throat and hoarseness.Results: There were no significant differences in the incidence of sore throat at 24 h following surgery (57.8% vs. 46.5%; P = 0.290) or in the incidence and intensity of sore throat and hoarseness at 1, 6, and 24 h following surgery between the groups. Conclusions: A. vulgaris in glycerine did not significantly differ from dexamethasone for preventing sore throat and hoarseness owing to intubation.