High-flow nasal oxygen versus conventional oxygen therapy in patients with COVID-19 pneumonia and mild hypoxaemia: a randomised controlled trial

Abstract

RationaleIn patients with COVID-19 pneumonia and mild hypoxaemia, the clinical benefit of high-flow nasal oxygen (HFNO) remains unclear. We aimed to examine whether HFNO compared with conventional oxygen therapy (COT) could prevent escalation of respiratory support in this patient population.MethodsIn this multicentre, randomised, parallel-group, open-label trial, patients with COVID-19 pneumonia and peripheral oxygen saturation (SpO2) ≤92% who required oxygen therapy were randomised to HFNO or COT. The primary outcome was the rate of escalation of respiratory support (ie, continuous positive airway pressure, non-invasive ventilation or invasive mechanical ventilation) within 28 days. Among secondary outcomes, clinical recovery was defined as the improvement in oxygenation (SpO2 ≥96% with fractional inspired oxygen (FiO2) ≤30% or partial pressure of arterial carbon dioxide/FiO2 ratio >300 mm Hg).ResultsAmong 364 randomised patients, 55 (30.3%) of 181 patients assigned to HFNO and 70 (38.6%) of 181 patients assigned to COT underwent escalation of respiratory support, with no significant difference between groups (absolute risk difference −8.2% (95% CI −18% to +1.4%); RR 0.79 (95% CI 0.59 to 1.05); p=0.09). There was no significant difference in clinical recovery (69.1% vs 60.8%; absolute risk difference 8.2% (95% CI −1.5% to +18.0%), RR 1.14 (95% CI 0.98 to 1.32)), intensive care unit admission (7.7% vs 11.0%, absolute risk difference −3.3% (95% CI −9.3% to +2.6%)), and in hospital length of stay (11 (IQR 8–17) vs 11 (IQR 7–20) days, absolute risk difference −1.0% (95% CI −3.1% to +1.1%)).ConclusionsAmong patients with COVID-19 pneumonia and mild hypoxaemia, the use of HFNO did not significantly reduce the likelihood of escalation of respiratory support.Trial registration numberNCT04655638.

High-flow nasal oxygen in individuals with COVID-19 pneumonia and mild hypoxaemia: An independent discussion

“…Original Discussion : The authors report that individuals with COVID-19 pneumonia and mild hypoxaemia randomised to HFNO versus COT had similar rates of RS escalation within 28 days. 9 …”

“…The study and control groups did not differ in the rate of the primary outcome. The sample size for the study 9 was calculated based on a retrospective study, the best evidence at the time. 12 However, effect size is often inflated in retrospective studies, 13 , 14 and indeed the observed rate of RS escalation was lower than expected.…”

“…In a recently published RCT, the COVID-HIGH trial, 9 individuals with COVID-19 and mild hypoxaemia were randomised to treatment with either HFNO or conventional oxygen therapy (COT). 9 The trial is particularly relevant as HFNO is increasingly being used in enviroments with a lower level of monitoring where such patients are often treated.…”

“…In a recently published RCT, the COVID-HIGH trial, 9 individuals with COVID-19 and mild hypoxaemia were randomised to treatment with either HFNO or conventional oxygen therapy (COT). 9 The trial is particularly relevant as HFNO is increasingly being used in enviroments with a lower level of monitoring where such patients are often treated. 10 , 11 With a structured independent discussion, 3 two authors with expertise in research methodology consider the findings and the inferential reproducibility of a RCT.…”

“… 10 , 11 With a structured independent discussion, 3 two authors with expertise in research methodology consider the findings and the inferential reproducibility of a RCT. Below, original and independent discussions for each section of the paper 9 are compared. 3 …”