Introduction
Difficult or failed tracheal intubation is a leading cause of anesthesia-related mortality and morbidity, ranging from soft tissue airway trauma to severe hypoxemia [1-3]. Direct laryngoscopy with the curved laryngoscope blade designed by Macintosh in 1943 [4] still represents the gold standard to perform endotracheal intubation. Strategies and guidelines for the management of predicted and unpredicted difficult airways have been published by the Difficult Airway Society of the UK [5-7], as by many other national societies. They incorporate essentially external airway maneuvers and patient positioning, direct laryngoscopy and stylets, extraglottic devices, fiberoptic bronchoscopy, as well as surgical techniques. Following the significant progresses in fiberoptic and video technologies, a wide variety of intubation devices have been developed recently and transposed into clinical practice. This may lead to changes in management with regard to the difficult airways. Studies are on their way [8], but the place of these new airway devices in clinical practice must be further assessed. Recognizing a difficult airway remains a challenge and the absence of any single sensitive predictive factor may lead to unexpected dangerous situations [9]. Difficult intubation ranges between 0.1% to 10.1%, depending on the definition [10], and rates as high as 8-30% have been reported in neurosurgical or ENT (ear, nose and throat) patients [11, 12]. Indeed, in patients with cervical spine injury, securing the airway while correctly immobilizing the cervical spine to avoid secondary neurological damage may be challenging. ENT disease, previous surgery, radiotherapy and chemotherapy, may lead to airway narrowing or distortion at laryngeal, sub-glottic or tracheal level.
The aim of this study was to compare the management of difficult intubation before and after the introduction of the Airtraq® and the Glidescope® in our institution for patients undergoing neurosurgical or ENT procedures necessitating tracheal intubation. We also analyzed the criteria used by anesthesiologists in our teaching hospital to predict difficult intubation in the same population.