Three Inflation Methods of Ambú Auragain™ and Its Adverse Effects

Laryngeal mask is a common supraglottic device (SGD) used in the daily practice for airway management. Consecutive generations have permitted an expansion of its use. At the moment, the SGD is being used in several situations, which include general anesthesia, cardiopulmonary resuscitation, and difficult airway management. To insert the SGD safely in these situations, the Fourth National Audit Project has encouraged the use of second-generation SGD equipped with the passage of a nasogastric tube. Ambu Auragain™ is a recent second-generation SGD with an incorporated gastric drainage channel and the capability of working as a conduit for tracheal intubation. It has higher leak pressure than the ones of first generation, which is a key marker of efficacy and safety of its use; a higher leak pressure suggests a better seal between the artificial airway and patient's airway. However, there are still few reports of which volume of cuff is the most appropriate for it use. The cuff inflating volume is not standardized and it is common practice to inflate the SGD cuff according to the manufacturer's recommendations, without using a manometer. A hyperinflation of the laryngeal mask cuff was associated with complications ranging from sore throat, or dysphagia and dysphonia, to more serious complications such as paralysis of the vocal cord, arytenoid cartilages dislocation, recurrent laryngeal nerve injury and hypoglossal nerve injury. Also, the excess of volume or pressure is related to poor ventilation and increase the risk of gastric insufflation. The aim of this study is to evaluate the best cuff inflation method, in order to limit the intracuff pressure beyond the recommended maximum pressure (PM \< 60 cmH2O) and to allows decrease the pharyngo-laryngeal complications. The Primary outcome is to compare three different cuff inflating methods using Auragain™ laryngeal mask during fibro bronchoscopy and endobronchial ultrasound (EBUS) procedures, and to control the intra