Treating hypoxic patients with HFNC

Michael Allison, MD
26th Nov 2020

Once you’ve gotten the hang of the inner workings of high-flow nasal cannula (HFNC), you’re ready to make the jump to the clinical applications of this oxygen therapy. 

Remember that high-flow nasal cannula works by reducing oxygen dilution, improving functional residual capacity (FRC), and creating more efficient breathing through dead space washout. 

For a moment, think about a patient you might see presenting with pneumonia. You’ve astutely ordered a chest x-ray, confirmed the diagnoses, and started antibiotics. But your patient’s oxygen saturations continue to drop even when you place them on traditional nasal cannula.

Female patient with pneumonia and low blood oxygen. Cartoon.

Figure 1. Patients with pneumonia may have low blood oxygen levels (i.e., hypoxia) and therefore require more oxygen than a traditional nasal cannula can deliver.

 

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Your patient needs more oxygen, but how are you going to deliver it? Turn the regular nasal cannula up? Place the patient on oxygen via facemask? How about a move to noninvasive ventilation (NIV)?

Hopefully you’ve considered high-flow nasal cannula! HFNC has been most robustly studied in patients with hypoxic respiratory failure.

In fact, when put head to head against both traditional oxygen therapy and noninvasive ventilation in patients with hypoxic respiratory failure, HFNC was found to reduce the need for intubation in the sickest patients, and was able to reduce mortality at 90 days.

Woman with tubing across her face and nose. Endotrachial tube. Headstone. Illustration

Figure 2. In patients with hypoxic respiratory failure, high-flow nasal cannula (HFNC) was found to reduce the need for intubation in the sickest patients, and was able to reduce mortality at 90 days when compared to traditional nasal cannula and noninvasive ventilation (NIV).

It is important to understand that these studies were carried out in patients without a number of medical problems—notably heart failure and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). But these patients were very sick, and many had bilateral pneumonias.

High-flow nasal cannula should be your next step in patients with worsening oxygen levels while on traditional nasal cannula. You’ll reduce their chances of intubation and you may just save a life! 

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Recommended reading

  • Dysart, K, Miller, TL, Wolfson, MR, et al. 2009. Research in high flow therapy: mechanisms of action. Respir Med. 103: 1400–1405. PMID: 19467849
  • Frat, JP, Thille, AW, Girault, C, et al. 2015. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med. 372: 2185–2196. PMID: 25981908
  • Hernández, G, Vaquero, C, Colinas, L, et al. 2016. Effect of postextubation high-flow nasal cannula vs noninvasive ventilation on reintubation and postextubation respiratory failure in high-risk patients: a randomized clinical trial. JAMA. 316: 1565–1574. PMID: 27706464
  • Hernández, G, Vaquero, C, González, P, et al. 2016. Effect of postextubation high-flow nasal cannula vs conventional oxygen therapy on reintubation in low-risk patients: a randomized clinical trial. JAMA. 315: 1354–1361. PMID: 26975498
  • Maggiore, SM, Idone, FA, Vaschetto, R, et al. 2014. Nasal high-flow versus venturi mask oxygen therapy after extubation. Effects of oxygenation, comfort and clinical outcome. Am J Respir Crit Care Med. 190: 282–288. PMID: 25003980
  • Mauri, T, Turrini, C, Eronia, N, et al. 2017. Physiologic effects of high-flow nasal cannula in acute hypoxemic respiratory failure. Am J Respir Crit Care Med. 195: 1207–1215. PMID: 27997805
  • Roca, O, Caralt, B, Messika, J, et al. 2019. An index combining respiratory rate and oxygenation to predict outcome of nasal high-flow therapy. Am J Respir Crit Care Med. 199: 1368–1376. PMID: 30576221
  • Roca, O, Messika, J, Caralt, B, et al. 2016. Predicting success of high-flow nasal cannula in pneumonia patients with hypoxemic respiratory failure: the utility of the ROX index. J Crit Care. 35: 200–205. PMID: 27481760
  • Sztrymf, B, Messika, J, Bertrand, F, et al. 2011. Beneficial effects of humidified high flow nasal oxygen in critical care patients: a prospective pilot study. Intensive Care Med. 37: 1780–1786. PMID: 21946925