Kashyap, Rahul

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 pO 2 /F IO 2 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 pO 2 /F IO 2 ≤315 [with S pO 2 ≤97%] or a P aO 2 /F IO 2 ≤300 mm Hg while receiving ≥30 L/min O 2 via HFNC) were included. The study evaluated the proportion of subjects who progressed to intubation, severity levels using the S pO 2 /F IO 2 cutoff proposed in the new ARDS definition, and mortality. Results: Nine hundred sixty-five non-intubated subjects with ARDS were included, of whom 27% ( n = 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) ( n = 225), and among subjects who progressed to the Berlin criteria, it was 37% (95% CI 31–43) ( n = 98). Additionally, the worst S pO 2 /F IO 2 within 1 d of ARDS diagnosis was correlated with mortality, with mortality rates of 26% (95% CI 23–30) ( n = 177) for subjects with S pO 2 /F IO 2 ≤148, 17% (95% CI 12–23) ( n = 38) for those with S pO 2 /F IO 2 between 149–234, and 16% (95% CI 8–28) ( n = 10) for subjects maintaining an S pO 2 /F IO 2 higher than 235 ( P < .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 pO 2 /F IO 2 and ARDS severity cutoff proposed in the new Global ARDS definition were valuable predictors of in-hospital mortality in these subjects.