Effects of thermal softening of endotracheal tubes on postoperative sore throat: A randomized double-blinded trial

Background: Postoperative throat complications after intubation are undesirable but frequent outcomes. A randomized, double-blinded study was performed to determine whether thermal softening of endotracheal tubes reduced throat complications after intubation. Methods: Patients (n = 196) undergoing nasal surgery were randomly allocated into the control group and thermal softening groups. Sore throat and hoarseness were evaluated 1 and 24 hours after extubation. The severity of sore throat was evaluated using the numeric rating scale (NRS). The primary outcome was the incidence of sore throat 1 hour after extubation and sore throat was defined as a painful or scratchy feeling in the throat. The secondary outcomes were the incidence of hoarseness 1 hour after extubation, the incidence of sore throat and hoarseness 24 hours after extubation, severity of sore throat, and vocal cord injuries. Results: The incidence of sore throat 1 hour after extubation was lower in the thermal softening group than in the control group (35.1% vs 52.7%, P =.02). Moreover, thermal softening decreased the mean NRS score for sore throat in the thermal softening group by 10% an hour after extubation (thermal softening group, 1.29 [95% CI, 0.88-1.70] vs control group, 2.33 [95% CI, 1.77-2.89]; P <.01). At 24 hours after extubation, the incidence of sore throat (38.3% vs 40.7%, P =.77) and hoarseness (34.0% vs 35.2%, 0.95 [0.52-1.74], P =.74) were comparable between the two groups. Conclusions: Intubation using endotracheal tubes with thermal softening significantly decreased the incidence of sore throat 1 hour after extubation when compared with endotracheal tubes without thermal softening.