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January 24, 2022

Effect of Noninvasive Respiratory Strategies on Intubation or Mortality Among Patients With Acute Hypoxemic Respiratory Failure and COVID-19.

Mazen Kherallah

Summarized by: 

What was the research question?

  • Does the use of either continuous positive airway pressure (CPAP) or high-flow nasal oxygen (HFNO), improve clinical outcomes in hospitalized patients with COVD-19-related acute hypoxemic respiratory failure compared to conventional oxygen therapy (COT)?

How did they do it?

  • A parallel group, adaptive, randomized clinical trial in 28 hospitals the UK and Jersey.

  • 1273 hospitalized adult patients with COVID-19–related acute hypoxemic respiratory failure, were randomized to receive CPAP (n = 380), HFNO (n = 418), or conventional oxygen therapy (n = 475).

  • Comparisons excluded patients who did not have an opportunity to be randomized to the alternative intervention based on the availability CPAP of HFNO in the hospital site (356 patients in the COT group were compared with CPAP vs. 368 patients in the COT group were compared with HFNO).

  • Planned to recruit 4002 patients.

  • The primary outcome was a composite of tracheal intubation or mortality within 30 days.

What did they find?

  • The trial was stopped prematurely due to declining COVID-19 case numbers in the UK and the end of the funded recruitment period.

  • The composite of tracheal intubation or mortality within 30 days was significantly lower with CPAP compared to COT (36.3% vs 44.4%, absolute difference, −8% [95% CI, −15% to −1%], P = .03), but was not significantly different with HFNO compared to COT (44.3% vs. 45.1%; absolute difference, −1% [95% CI, −8% to 6%], P = .83).

  • Adverse events occurred in 34.2% of participants in the CPAP group, 20.6% in the HFNO group, and 13.9% in the conventional oxygen therapy group.

Are there any limitations?

  • Potential of type II error as the trial was stopped prematurely.

What does it mean?

  • CPAP but not HFNO reduces the risk of tracheal intubation or mortality in patients with acute hypoxemic respiratory failure due to COVID-19 compared to COT. However, the study is underpowered for HFNO compared to COT.


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