Postoperative sore throat and subglottic injury after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score: a randomized controlled trial

Abstract

Background A tracheal tube stylet can be used to assist successful tracheal intubation, especially during videolaryngoscopic intubation because videolaryngoscopes with a Macintosh-type blade such as McGrath® MAC videolaryngoscope have more acute angle than conventional Macintosh laryngoscope. However, the use of a stylet during tracheal intubation can raise concerns about stylet-induced postoperative airway complications, such as sore throat, subglottic injury, and hoarseness. In this study, we compared the incidence of postoperative airway complications after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score. Methods In 104 patients with Mallampati score III or IV and who were scheduled for lumbar or thoracic spine surgery, McGrath® MAC videolaryngoscopic intubation was performed either with a stylet (group S, n = 52) or without a stylet (group N, n = 52). The primary outcome measure was the incidences of sore throat evaluated at 1 and 24 h postoperatively. Secondary outcome measures were the incidences of subglottic injury and postoperative hoarseness. Results The incidence of CL grade III in group S and N was 3.8 and 5.8%, respectively. No patient showed CL grade IV. The incidences of sore throat at 1 (26.9 vs 19.2%, P = 0.485) and 24 h (17.3 vs 13.5%, P = 0.786, respectively) postoperatively were not significantly different between the group S and N. However, the incidence of subglottic injury was significantly higher in the group S, compared with the group N (65.4 vs 42.3%, P = 0.030). The incidence of postoperative hoarseness did not differ significantly between the two groups. Conclusions The use of a stylet during McGrath® MAC videolaryngoscopic intubation did not have a significant impact on the incidence of postoperative sore throat in patients with a high Mallampati score. Avoiding the use of a stylet during intubation with McGrath® MAC videolaryngoscope may reduce the incidence of subglottic injury in such patients. Trial registration Clinical Research Information Service (identifier: KCT0002427 , date of registration: June 12, 2017).

Ultrasound-Guided Block of the Internal Branch of the Superior Laryngeal Nerve Reduces Postoperative Sore Throat Caused by Suspension Laryngoscopic Surgery: A Prospective Randomized Trial

“…Therefore, POST is not only a postoperative complication but also an intubation- and extubation-related complication. These procedures might produce subglottic injury and upper airway mucosal injury that induce POST ( 20 ). Although POST appears short-lived and usually resolves within a week or less, it should be viewed as a preventable side effect in the era of early enhanced recovery surgery in which patients return to full function as early as possible ( 21 ).…”

Evaluation of transmitted glow point at a priori chosen depth (1 cm below vocal cords) for lightwand intubation: a prospective observational study

“…Although this was not proven in our study, some previous articles have described tracheal injury by a stylet. 9 , 11 , 13 – 17 Therefore, we evaluated the efficacy of the lightwand tip located 1 cm below the vocal cords for lightwand intubation and assessed the corresponding point for the position of the lightwand tip on the patient’s neck.…”

“…In our literature review, some reports indicated that use of a stylet could cause tracheal injury. 9 , 11 , 13 – 17 We considered that such tracheal injury due to use of a stylet may result from over-insertion of the stylet into the tracheal tube before intubation, rapid and powerful advancement of the combined tracheal tube and stylet into the trachea, or unnecessary deep insertion of the combined tracheal tube and stylet into the trachea. The lightwand is a type of stylet often referred to as a lighted stylet.…”

“…Additionally, we considered that a too-shallow tube depth can lead to intubation failure or laryngeal damage such as arytenoid cartilage subluxation or vocal cord injury according to our clinical experiences and a literature review. 9 – 13 The purpose of this study was to explore the transmitted glow point corresponding to a priori chosen depth (1 cm below the vocal cords) for lightwand intubation.…”

Combined use of a Total Control Introducer and a hyperangulated video laryngoscope to place a left-sided double lumen endotracheal tube in a patient with a history of difficult laryngoscopy

“…Not surprisingly, a recent study demonstrated increased anterior tracheal tissue injury when rigid stylets were used with VL as opposed to no stylet. 15 One method to overcome the challenge of airway navigation is combining the use of VL with FOB. Multiple studies have demonstrated this 'combined technique' to facilitate intubation of the difficult airway.…”