High Flow Nasal Cannula (HFNC) in acute respiratory hypoxemia

• HFNC has been used for a variety of patients with respiratory distress (See previous pearl: https://umem.org/educational_pearls/2411/)
• The benefits include:

1. Low levels of positive pressure in the upper airways
2. High flow rates, titratable oxygen levels, humidied air, more comfort than NIV
3. Decreases physiological dead space by flushing out CO2 therefore improving oxygenation

• A recent trial published in NEJM looked at using HFNC in patients with respiratory failure

The Trial:

• Patients without hypercapnia and with acute hypoxemic respiratory failure (PaO2/FiO2 <300 or less) were randomized to HFNC, standard oxygen therapy via face mask, or non-invasive positive pressure ventilation (NIV).
• Primary outcome was proportion of patients intubated at day 28
• 310 patients in European ICUs

Results:

• Intubation rate (p=0.18): 38% in the HFNC; 47% in the standard group; 50% in the NIV
• Number of ventilator free days at day 28 was significantly higher in the HFNC
• Higher mortality at 90 days with NIV
• No difference in intubation rates but there were more ventilator free dates as well as a lower 90 day mortality

Bottom line:

Consider using HFNC prior to or while deciding on intubation in patients with hypoxemic respiratory failure usually due to pneumonia

References