Evaluating the Newly Proposed ARDS Definition in Hospitalized Patients With COVID-19 Treated With High-Flow Nasal Oxygen.

Background: The new Global definition of ARDS recently introduced a subgroup known as non-intubated ARDS. This study aimed to assess the risk of progression from noninvasive oxygen support to intubation and ARDS severity based on the S /F among non-intubated subjects with ARDS.

Methods: This retrospective study included subjects with COVID-19 admitted to 7 hospitals (5 in the United States and 2 in Argentina) from January 2020-January 2023. Subjects meeting the new non-intubated ARDS definition (high-flow nasal cannula [HFNC] with an S /F ≤ 315 [with S ≤ 97%] or a P /F ≤ 300 mm Hg while receiving ≥30 L/min O via HFNC) were included. The study evaluated the proportion of subjects who progressed to intubation, severity levels using the S /F cutoff proposed in the new ARDS definition, and mortality.

Results: Nine hundred sixty-five non-intubated subjects with ARDS were included, of whom 27% ( 262) progressed to meet the Berlin criteria within a median of 3 d (interquartile range 2-6). The overall mortality was 23% (95% CI 20-26) ( = 225), and among subjects who progressed to the Berlin criteria, it was 37% (95% CI 31-43) ( = 98). Additionally, the worst S /F within 1 d of ARDS diagnosis was correlated with mortality, with mortality rates of 26% (95% CI 23-30) ( 177) for subjects with S /F ≤ 148, 17% (95% CI 12-23) ( 38) for those with S /F between 149-234, and 16% (95% CI 8-28) ( 10) for subjects maintaining an S /F higher than 235 ( < .001).

Conclusions: The non-intubated ARDS criteria encompassed a broader spectrum of subjects with lower in-hospital mortality compared to the Berlin criteria. The S /F and ARDS severity cutoff proposed in the new Global ARDS definition were valuable predictors of in-hospital mortality in these subjects.