Airway Injuries After Intubation Using Videolaryngoscopy Highly Curved Blades Versus Direct Laryngoscopy for Adult Patients Requiring Tracheal Intubation: a Randomized Controlled Trial

Abstract Background Successful tracheal intubation during general anesthesia requires a direct laryngoscope to retract the tongue and soft tissues of the mouth to achieve a line of sight for the larynx. Generally, Macintosh blade laryngoscopy is used to achieve the tracheal intubation. However, difficulties with the tracheal intubation arise the need to use alternative laryngoscopes that use digital or fiberoptic technology, to improve the larynx visibility. Among these devices, highly curved blade videolaryngoscope uses a curved blade to retract the soft tissues of floor of the mouth and transmits a video image to a screen, achieving better larynx visibility. Also, the decrease of the force in the soft tissues with videolaryngoscope could reduce airway injures.

Objectives Our primary objective is to assess whether use of videolaryngoscopy using highly curved blades for tracheal intubation in adults requiring general anesthesia reduces risk of airways injuries compared with Macintosh direct laryngoscopy. Our secondary aim is to assess postoperative satisfaction of the patients, successful intubation at the first attempt, successful global intubation, degree of larynx visibility according to classification Cormack - Lehane and time taken to perform intubation in videolaryngoscopy vs direct laryngoscopy. Finally, we assess the risk of presenting serious adverse event with the use of videolaryngoscopy compared with Macintosh laryngoscopy in hypoxemia, bradycardia and heart arrest.