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.

BACKGROUND: Use of high-flow nasal oxygen (HFNO) for treatment of adults with acute respiratory failure (ARF) has increased. PURPOSE: To assess HFNO versus noninvasive ventilation (NIV) or conventional oxygen therapy (COT) for ARF in hospitalized adults. DATA SOURCES: English-language searches of MEDLINE, Embase, CINAHL, and Cochrane Library from January 2000 to July 2020; systematic review reference lists. STUDY SELECTION: 29 randomized controlled trials evaluated HFNO versus NIV (k = 11) or COT (k = 21). DATA EXTRACTION: Data extraction by a single investigator was verified by a second, 2 investigators assessed risk of bias, and evidence certainty was determined by consensus. DATA SYNTHESIS: Results are reported separately for HFNO versus NIV, for HFNO versus COT, and by initial or postextubation management. Compared with NIV, HFNO may reduce all-cause mortality, intubation, and hospital-acquired pneumonia and improve patient comfort in initial ARF management (low-certainty evidence) but not in postextubation management. Compared with COT, HFNO may reduce reintubation and improve patient comfort in postextubation ARF management (low-certainty evidence). LIMITATIONS: Trials varied in populations enrolled, ARF causes, and treatment protocols. Trial design, sample size, duration of treatment and follow-up, and results reporting were often insufficient to adequately assess many outcomes. Protocols, clinician and health system training, cost, and resource use were poorly characterized. CONCLUSION: Compared with NIV, HFNO as initial ARF management may improve several clinical outcomes. Compared with COT, HFNO as postextubation management may reduce reintubations and improve patient comfort; HFNO resulted in fewer harms than NIV or COT. Broad applicability, including required clinician and health system experience and resource use, is not well known. PRIMARY FUNDING SOURCE: American College of Physicians. (PROSPERO: CRD42019146691).

Effectiveness and harms of high-flow nasal oxygen (HFNO) for acute respiratory failure: a systematic review protocol.

INTRODUCTION: High-flow nasal oxygen (HFNO) use in adults hospitalised with acute respiratory failure (ARF) is increasing. However, evidence to support widespread use of HFNO compared with non-invasive ventilation (NIV) and conventional oxygen therapy (COT) is unclear. This protocol describes the methods for a systematic evidence review regarding the comparative effectiveness and harms of HFNO compared with NIV or COT for the management of ARF in hospitalised adult patients. METHODS AND ANALYSIS: We will search MEDLINE, Embase, CINAHL and Cochrane Library for randomised-controlled trials (RCTs) of adult patients hospitalised with ARF or who developed ARF while hospitalised. ARF will be defined as SpO 2 <90%, PaO 2 :FiO 2 ratio ≤300, PaO 2 ≤60 mm Hg, or PaCO 2 ≥45 mm Hg. The intervention is HFNO (humidified oxygen, flow rate ≥20 L/min) compared separately to NIV or COT. The critical outcomes are: all-cause mortality, hospital-acquired pneumonia, intubation/reintubation (days of intubation), intensive care unit admission/transfers, patient comfort and hospital length of stay. The important outcomes are: delirium, 30-day hospital readmissions, barotrauma, compromised nutrition (enteral or parenteral nutrition), gastric dysfunction, functional independence at discharge and skin breakdown or pressure ulcers. We will calculate risk ratios and Peto ORs (for rare events) and corresponding 95% CIs for categorical outcomes. Mean and standardised mean difference will be calculated for continuous outcomes. Where possible and appropriate, meta-analysis will be performed for each outcome. CONCLUSION: This systematic review will provide a comprehensive evaluation of the evidence regarding the comparative effectiveness and harms of HFNO compared with NIV or COT for the management of ARF in hospitalised adult patients to inform clinical practice and to identify research gaps in the management of ARF in hospitalised adults. The results will inform the work of the American College of Physicians-Clinical Guidelines Committee in their development of a clinical guideline related to use of HFNO in adult patients with ARF. ETHICS AND DISSEMINATION: No ethical approval will be needed because we will be using data from previously published studies in which informed consent was obtained by the primary investigators. We will publish our results in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019146691.