Flexible video endoscope versus Macintosh laryngoscope for orotracheal tracheal intubation in the lateral position: a study protocol for a randomized controlled trial

BACKGROUND: Tracheal intubation with the patient in the lateral position is difficult because the laryngeal view is compromised during direct laryngoscopy. Flexible video endoscopes may facilitate intubation even when laryngeal views are poor on direct laryngoscopy because the patients are positioned laterally. Thus, this trial aims to compare the efficacy of flexible video endoscopes to Macintosh laryngoscopes for orotracheal intubation in the lateral position and to investigate their feasibility, i.e., whether the use of the two devices in combination can secure the airway when endotracheal intubation in the lateral position has failed using one device. METHODS: This will be a prospective, randomized, single-center, clinical trial. One hundred and seventy-four patients aged 18–65 years, who have been scheduled to undergo tracheal intubation under uniform general anesthetic techniques for elective kidney surgery in the lateral decubitus position will be randomly divided into the flexible video endoscope and the Macintosh laryngoscope groups. Primary outcomes include intubation time and intubation success rate. Secondary outcomes include overall user satisfaction (graded from 1 to 10 (1 = very poor, 10 = excellent)) and perioperative side effects and complications, such as frequency of esophageal intubation, lip or dental injury, sore throat, and hoarseness. DISCUSSION: The trial will clarify the efficacy of intubation with a Macintosh laryngoscope and a flexible video endoscope in the lateral position, and whether the two devices could be used in combination to secure the airway in cases where endotracheal intubation in the lateral position has failed with one device. TRIAL REGISTRATION: Chinese Clinical Trial Register, ChiCTR- IOR-15007175. Registered on 6 October 2015. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3263-1) contains supplementary material, which is available to authorized users.