Apneic Oxygenation With High-flow Nasal Oxygenation After Preoxygenation With Noninvasive Ventilation Before Intubation in Hypoxemic Patients in Intensive Care Unit.

"* Preoxygenation will be performed using NIV for 3-5 min With nasal cannulas placed in standby beneath the patient's chin (with HFNO on and set with a flow at 60-70L.min-1, FiO2 1.0)~* Rapide sequence induction~* Hypoventilation phase will be continue for 1 min using NIV~* At the time of laryngoscopy :~After removing the facemask, the nasal cannulas of HFNO will be placed in the patient's nares then the laryngoscopy will be performed.~\* Use of capnography to confirm the success of procedure"

"* Preoxygenation will be performed using NIV for 3-5 min without HFNO~* Rapide sequence induction~* Hypoventilation phase will be continue using NIV for 1min~* At the time of laryngoscopy :~After removing the facemask, laryngoscopy will be performed without oxygen.~\* Use of capnography to confirm the success of procedure"