The American College of Physicians’ (ACP) Clinical Guidelines Committee (CGC) has published a guideline providing evidence-based recommendations on the appropriate use of high-flow nasal oxygen (HFNO) in hospitalized patients with acute respiratory failure. The recommendations were published online in the Annals of Internal Medicine.1,2

Guideline Development: Research Review

In a review of 29 randomized controlled trials evaluating HFNO vs noninvasive ventilation (NIV), the ACP found HFNO was slightly superior in its ability to reduce all-cause mortality, intubation, and hospital acquired pneumonia when given as an initial treatment for acute respiratory failure.1 The use of HFNO as initial therapy was also associated with improvements in patient comfort and dyspnea compared with NIV and conventional oxygen therapy.1,2


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In contrast, HFNO was not superior to conventional oxygen therapy in its ability to reduce mortality, intubation, and length of hospital stay. Additionally, HFNO was deemed more expensive than conventional oxygen therapy as well as more resource intensive in terms of its implementation across health care systems.1,2

Recommendation: Clinicians Should Consider HFNO Over NIV

Based on their review of the evidence, the ACP CGC recommends clinicians should consider using HFNO vs NIV in hospitalized adults to treat acute hypoxemic respiratory failure.2

This was a conditional recommendation based on low-certainty evidence which showed HFNO provides a noticeable improvement in clinically meaningful outcomes in patients with acute hypoxemic respiratory failure. These documented “clinically meaningful outcomes” include substantial reductions in mortality in patients with hypoxemic, nonhypercapnic acute respiratory failure, as well as modest reductions in intubation among patients with hypoxemic and/or hypercapnic acute respiratory failure.2  

Despite making these recommendations, the CGC wrote there is insufficient evidence on the benefits of HFNO in patients with hypercapnic respiratory failure.1,2

According to the available evidence, the majority of patients with acute respiratory failure can use HFNO. There are no known contraindications to HFNO, unless there are issues with fitting the nasal cannula.2 Compared with NIV, costs related to HFNO tend to be lower, making the intervention much more accessible for patients and health care systems alike.2

Recommendation: Clinicians Should Consider HFNO Over Conventional Oxygen Therapy

In hospitalized adults with postextubation acute hypoxemic respiratory failure, the ACP wrote in its conditional recommendation that clinicians should choose HFNO over conventional oxygen therapy, as based on low-certainty evidence.2  

Low-certainty evidence found HFNO reduced reintubations slightly more than conventional oxygen therapy. Also, HFNO improved patient comfort better than conventional oxygen therapy in the reviewed studies.2

The evidence suggests that HFNO and conventional oxygen therapy are comparable in terms of their effects on all-cause mortality and hospital-acquired pneumonia. Additionally, moderate-certainty evidence has demonstrated HFNO may be similar to conventional oxygen therapy in regard to reducing length of intensive care unit stay.2

In the current COVID-19 pandemic era where viral spread remains a major health care concern, clinicians should be aware that HFNO is an aerosol-generating procedure. Therefore, the procedure requires higher grades of personal protective equipment than other types of routine procedures, making HFNO possibly more resource-intensive than conventional oxygen therapy.2

Clinical Considerations

The ACP wrote that the generalizability of the recommendations must be considered in the context of the reviewed evidence. For instance, many of the studies included in the review process enrolled patients with hypoxemic respiratory failure and at least moderate acute respiratory failure based on a baseline partial pressure of oxygen/fraction of inspired oxygen (PaO2/FIO2) ratio of <200 or oxygen saturation as measured by pulse oximetry (SpO2) of ≤88%.1

In addition, the studies included in the review did not always specify whether investigators excluded patients with hypercapnic acute respiratory failure. Studies that did enroll patients with hypoxemic and/or hypercapnic acute respiratory failure did not always provide details of the type of acute respiratory failure experienced by the patients.1,2

Likewise, the ACP CGC could not perform a direct comparison of NIV vs conventional oxygen therapy. The ACP noted in the guideline that in a recent review study, NIV improved outcomes better than conventional oxygen therapy in patients with acute hypoxemic respiratory failure.1,2

The ACP CGC wrote that broad applicability of HFNO, “including required clinician and health system experience and resource use, remains unknown.”1

Reference

1. Baldomero AK, Melzer AC, Greer N, et al. Effectiveness and harms of high-flow nasal oxygen for acute respiratory failure: an evidence report for a clinical guideline from the American College of Physicians. Ann Intern Med. Published online April 27, 2021. doi:10.7326/M20-4675

2. Qaseem A, Etxendia-Ikobaltzeta I, Fitterman N, Williams JW, Kansagara D; for the Clinical Guidelines Committee of the American College of Physicians. Appropriate use of high-flow nasal oxygen in hospitalized patients for initial or postextubation management of acute respiratory failure: a Clinical Guideline from the American College of Physicians. Ann Intern Med. Published online April 27, 2021. doi:10.7326/M20-7533