High-flow nasal cannula for COVID-19 respiratory failure doesn't reduce fatalities: SOHO Trial

FRANCE: According to a study published in JAMA Network, high-flow nasal cannula (HFNC) oxygen administration did not lower mortality among critically ill COVID-19 patients.

By 2022, the COVID-19 pandemic would have resulted in more than 6 million fatalities worldwide as a result of the adverse effects of acute hypoxemic respiratory failure. With COVID-19, conventional oxygen has been used as first-line therapy for up to 80% of patients admitted to hospitals and 45% of patients in intensive care units (ICUs) during subsequent waves.

"Retrospective observational studies revealed that high-flow oxygen had a lower chance of intubation than regular oxygen, but that survival was not increased. In patients with COVID-19-related respiratory failure, the efficacy of high-flow nasal cannula oxygen (high-flow oxygen) in terms of intubation and death is debatable," the authors wrote.

Researchers wanted to ascertain if the administration of high-flow oxygen, as opposed to conventional oxygen, could lower the probability of mortality on day 28 in patients referred to intensive care units with respiratory failure caused by COVID-19.

711 patients with COVID-19-related respiratory failure and a partial pressure of arterial oxygen to fraction of inspired oxygen ratio of 200 mm Hg or less were involved in the SOHO-COVID randomized clinical trial, which was carried out in 34 ICUs in France. The allocation of patients to receive either high-flow oxygen (n = 357) or regular oxygen through a nonrebreathing mask with an initial setting of 10 L/min was done at random (n = 354). Acute hypoxemic respiratory failure from any cause was intended to be included in this auxiliary trial, which was part of the ongoing original SOHO randomized clinical trial. Patients were enrolled between January and December of 2021, with the last follow-up taking place on March 5 of 2022.

Conclusive points of the study:

• At day 28, the mortality rate with high-flow oxygen was 10% (36/357) and with regular oxygen, it was 11% (40/354) (absolute difference: -1.2% [95% CI: -5.8% to 3.4%]; P =.60).
• 12 of the 13 predetermined secondary outcomes—including length of stay, ICU mortality, and mortality through day 90—showed no statistically significant difference.
• High-flow oxygen substantially reduced the rate of intubation (45% [160/357] vs 53% [186/354]; absolute difference, -7.7% [95% CI, -14.9% to -0.4%]; P =.04) compared to conventional oxygen.
• At day 28, there was no discernible distinction between the groups in the median number of ventilator-free days (28 [IQR, 11-28] vs. 23 [IQR, 10-28] days; absolute difference, 0.5 days [95% CI, -7.7 to 9.1]; P =.07).
• In both the high-flow oxygen group (58%) and the conventional oxygen group (53%), ventilator-associated pneumonia was the most frequent adverse event.

"The reduced incidence of intubation and need for invasive mechanical ventilation may be seen as a meaningful outcome for patients with acute respiratory failure, even if high-flow oxygen had no discernible impact on the primary outcome of mortality. Additionally, it might assist in preventing the usage of ICU ventilators in locations with limited resources during a pandemic," asserted the investigators.

The authors concluded that the present trial has various advantages that point to the possibility that the findings might be used to patients treated for respiratory failure caused by COVID-19 in different ICUs and nations.

REFERENCE

Frat J, Quenot J, Badie J, et al. Effect of High-Flow Nasal Cannula Oxygen vs Standard Oxygen Therapy on Mortality in Patients With Respiratory Failure Due to COVID-19: The SOHO-COVID Randomized Clinical Trial. JAMA. 2022;328(12):1212–1222. doi:10.1001/jama.2022.15613