Monday, April 15, 2019


R.E.B.E.L.EM - April 15, 2019 - By Salim Rezaie
Ref: Frat JP et al. Non-Invasive Ventilation Versus High-Flow Nasal Cannula Oxygen Therapy with Apnoeic Oxygenation for Preoxygenation Before Intubation of Patients with Acute Hypoxaemic Respiratory Failure: A Randomised, Multicentre, Open-Label Trial. Lancet Respir Med 2019. PMID: 30898520

..."Author Conclusion:“In patients with acute hypoxaemic respiratory failure, preoxygenation with non-invasive ventilation or high-flow oxygen therapy did not change the risk of severe hypoxaemia. Future research should explore the effect of preoxygenation method in patients with moderate-to-severe hypoxaemia at baseline.” 
Clinical Take Home Point: It’s hard to know what to take away from this study, as the comparisons were far from fair or even optimal. As a matter of fact, we are comparing apples to oranges. In a population of patients with severe shunt physiology we are comparing NIV (increased alveolar recruitment through higher levels of PEEP and no nasal/apneic oxygenation) to HFNC (a lower magnitude of alveolar recruitment with lower levels of PEEP + nasal/apneic oxygenation) during laryngoscopy. Essentially, less than optimal pre-oxygenation (NIV alone) with even worse pre-oxygenation (HFNC alone).
In patients with shunt physiology we must optimize pre-oxygenation by recruiting atelectatic alveoli with the best tools we have available:
  1. Increasing PEEP via BVM + PEEP valve with flush rate oxygen AND
  2. Nasal/Apneic oxygenation"