Comparison of Two Methods of Preoxygenation Before Oro Tracheal Intubation in the Hypoxemic Patient in Intensive Care Unit : Non Invasive Ventilation (NIV) + High Flow Nasal Cannula Oxygen Versus NIV Alone : a Randomized Controlled Study

Patients admitted in Intensive Care Unit (ICU) often need respiratory support. Endotracheal intubation procedure in ICU is associated with severe life threatening complications. In order to decrease the incidence of complications including hypoxemia during intubation procedure, a preoxygenation is recommended, consisting in the administration of pure oxygen before intubation.

Recent data suggest that NIV use for preoxygenation of patients with acute respiratory failure is associated with less hypoxemia during intubation procedure than classic preoxygenation with facial mask. Indeed, associating Pressure Support (PS) with Positive end expiratory pressure (PEEP) limits the alveolar collapse and atelectasis formation. NIV is now used by a lot of of teams for preoxygenation of patients with acute respiratory failure in ICU.

However, although NIV is effective to reduce hypoxemia during intubation procedure, NIV mask has to be taken off after preoxygenation in order to allow the passage of the oro tracheal tube through the mouth. The hypoxemic patient does not receive oxygen during this period, which participates to the episodes of major hypoxemia during intubation.

In contrast, HFNC, which delivers high flow heated and humidified oxygen and air via nasal prongs at a prescribed fraction of inspired oxygen and a maximum flow of 60 L/min can be pursued during the intubation procedure. Some very recent studies suggest that HNFC could allow apneic oxygenation.

Although use of HFNC combined to NIV may have potential advantages over conventional NIV for preoxygenation before intubation in hypoxemic ICU patients, this technique of preoxygenation has never been assessed and benefit remains to be established.