GlideScope® vs GlideScope® + aScope® for Managing Difficult Airways.

Worldwide, up to 600 patients are estimated to die annually as a result of the complications that occur during tracheal intubation The GlideScope® (videolaryngoscope) is used for endotracheal intubation in patients with difficult airway predictors, in this patients overall success intubation rate is 96%. but success intubation rate at first attempt is only 86%. Despite this positive rates, due to high comorbidity when intubation fails, both failure rates (inverse of success rate) are impermissible. 14% failure at the first attempt intubation as well as 4% overall intubation failure. in this study the investigators try to show that new procedure associating aScope® (disposable fiberscope) together with GlideScope® increases the success intubation rate of both ( overall and first attempt).