Discussion
’s mouth, glottis, epiglottis
In this randomized parallel-group study, we showed that all three devices were ultimately effective for intubation, higher first-pass intubation success rates were obtained with the video stylet and the flexible videoscope. Endotracheal intubation with the video stylet resulted in shorter intubation time when compared with the video laryngoscope and flexible videoscope. Glottic exposure in patients with difficult airways is a major challenge when managing the airway, endotracheal intubation with flexible videoscope and video stylet having much better glottic exposure capabilities than video laryngoscope. Clearly, for the management of patients with difficult airways, video stylet and flexible videoscope perform much better.The increasing number of airway management devices that are being developed and used has changed the definition of a difficult airway [The video stylet does not require a large degree of mouth opening and head tilt and does not require the epiglottis to be lifted, which may effectively reduce the degree and force of instruments contacted with the oropharynx. Therefore, the damage to the oropharyngeal mucosa caused by intubation is reduced, which is an obvious advantage for intubation in patients with cervical bracing [The flexible videoscope has the advantage of not limiting the diameter of the tracheal tube and, due to the softness of its light-guiding hose, is also better than a regular video laryngoscope in terms of reducing damage to the patient’s mouth and airway during intubation. However, we found that its intubation time was longer than that of the video laryngoscope and video stylet, probably because the flexible videoscope light-guiding hose was difficult to fix during the operation and it was more difficult to operate. Additionally, because muscarinic drugs and gravity reduce tension in the epiglottis and tongue, an assistant sometimes was needed to tilt the head back and elevate the jaw to open the epiglottis and obtain a view of the glottis. Tracheal intubation using a fiberscope takes longer than that with an endoscope [This study has two limitations, as described below. Firstly, the criteria for recruiting subjects may not include all patients who meet the definition of a difficult airway. For example, in recent studies, supraglottic and subglottic ultrasound measurements or upper lip biting tests have been performed to predict a difficult airway [