Effect of thermal softening of double-lumen endobronchial tubes on postoperative sore throat in patients with prior SARS-CoV-2 infection: a randomized controlled trial

Abstract

Abstract Background The incidence of postoperative sore throat (POST) after tracheal intubation using double-lumen endobronchial tubes (DLTs) is higher in patients with prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than in the general population. This prospective trial was conducted to determine whether thermal softening of DLTs could decrease the incidence of POST or other airway injuries in patients with prior SARS-CoV-2 infection. Methods A total of 120 patients with prior SARS-CoV-2 infection undergoing thoracoscopic surgery were randomly assigned to two groups (n = 60 each). In the thermal softening group, the distal portion of the DLT was placed in thermostatic saline (50 °C) for 10 min before endotracheal intubation. In the control group, the distal portion of the DLT was placed in room temperature saline for 10 min before endotracheal intubation. The incidence and severity of POST and hoarseness were assessed at 1, 6 and 24 h postoperatively. The primary outcomes were the incidence and severity of POST at 6 h postoperatively. The secondary outcomes were the incidence and severity of hoarseness, vocal cord and tracheal injuries, and hemodynamic changes in patients at intubation. Results The incidence of POST at 6 h postoperatively was greater in the control group than in the thermal softening group [41 (68%) vs. 22 (37%), P = 0.001]. The overall incidence of POST at 24 h postoperatively was greater in the control group than in the thermal softening group [46 (76%) vs. 24 (40%), P < 0.001]. The overall incidence of tracheal injuries was also greater in the control group than in the thermal softening group (P = 0.016). Vocal cord injuries occurred more frequently in the control group than in the thermal softening group (P = 0.006). Conclusion Thermal softening of DLTs before intubation can reduce the incidence of POST and airway injuries in patients with prior SARS-CoV-2 infection undergoing DLT insertion. Trial registration This trial has been registered at www.chictr.org.cn (registration number: ChiCTR2200066821; registration date: December 19, 2022).