Penetrating injury of the soft palate by a microlaryngeal tracheal tube during GlideScope® intubation

Dear Editor, A 57-year-old man presented for suspension microlaryngoscopy and biopsy of a laryngeal lesion that was mildly obstructive. After induction of general anaesthesia, a standard midline approach of glideScope laryngoscopy provided good laryngeal exposure. A junior anaesthesiologist made a failed attempt to introduce a 5.0-mm internal diameter cuffed microlaryngeal tracheal (MlT) tube with a malleable stylet curved at 90o in the larynx to facilitate intubation. A slight resistance was encountered while passing the tube into the oropharyngeal cavity and a trace of blood was noted at the tip of the MlT tube upon removing it. Another attempt was made by an experienced anaesthesiologist, during which it was noticed on the screen that the tube was inserted completely behind the pharyngeal mucosa that was lifted up. The tube was withdrawn immediately and with fine manoeuvres reinserted between the vocal cords. The otorhinolaryngologist found severe right sided perforation of the soft palate, which resulted in a lateral pharyngeal wall haematoma with subsequent narrowing of the hypopharyngeal lumen and upper airway. We suspect that the soft palate was perforated during the first pass of the tube which made an entry point to the tube creating a false passage in the pharynx. The false passage was eventually filled with blood after withdrawing the tube and the haematoma was formed. The laceration of the soft palate was sutured and the patient was kept intubated for 24 hours for any unexpected events that might lead to airway obstruction. The next day, the patient was extubated uneventfully and was discharged the day after. Complications of glideScope videolaryngoscopy have been described in the literature. With the use of glideScope, like any other airway device, there is always a risk of trauma to the pharyngeal mucosa. The risk of trauma to the soft tissue is greatest during passage of the styletted tube through the “blind spot” that exists at the point where the operator loses sight of the endotracheal tube (ETT) tip at the back of the pharynx until it resurfaces within the camera’s visual field. in addition, when upward force is applied to the glideScope, the tonsils and structures around become stretched and vulnerable to perforation. All injuries reported in association with the use of glideScope videolaryngoscopy were simple laceration and caused by ETT size 7-mm internal diameter or more. in our patient, however, the injury was significant and the tube used was a small size MlT. it is well known that applying the same force to a smaller surface area would result in higher pressure, which means more pressure may be applied using an ETT of narrower diameter. The relatively high pressure may have caused the tip of the tube to cut through oral tissue even though minimal force was applied. Consequently, a styletted sharp-edged small tube with a less surface area, such as the MlT, might be considered as risk factor for causing soft tissue injury. of note, we used a malleable stylet because the rigid gli-