inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio ≤200 with peep ≥8 cm h2o and fio2≥0.6; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 72h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days of exposure to an ards-risk factor (including continuous exposure to persistent processes (e.g. sepsis, pneumonia, covid-19). patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio ≤ 200 are met and then randomized if and when the p/f ratio ≤200 (as long as this occurs within 72h of randomization). patients on high flow nasal oxygen or non-invasive pressure ventilation may be consented if they meet criteria for starting the 72h ards window but may not be enrolled and randomized until they are intubated.

inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio ≤200 with peep ≥8 cm h2o and fio2≥0.6; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 72h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days of exposure to an ards-risk factor (including continuous exposure to persistent processes (e.g. sepsis, pneumonia, covid-19). patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio ≤ 200 are met and then randomized if and when the p/f ratio ≤200 (as long as this occurs within 72h of randomization). patients on high flow nasal oxygen or non-invasive pressure ventilation may be consented if they meet criteria for starting the 72h ards window but may not be enrolled and randomized until they are intubated.

inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio ≤200 with peep ≥8 cm h2o and fio2≥0.6; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 72h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days of exposure to an ards-risk factor (including continuous exposure to persistent processes (e.g. sepsis, pneumonia, covid-19). patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio ≤ 200 are met and then randomized if and when the p/f ratio ≤200 (as long as this occurs within 72h of randomization).

inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio ≤200 with peep ≥8 cm h2o and fio2≥0.6; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 72h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days of exposure to an ards-risk factor (including continuous exposure to persistent processes (e.g. sepsis, pneumonia, covid-19). patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio ≤ 200 are met and then randomized if and when the p/f ratio ≤200 (as long as this occurs within 72h of randomization).

inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio <200 with peep ≥8 cm h2o; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 48h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days onset of a condition associated with ards. patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio < 200 are met and then randomized if and when the p/f ratio < 200 (as long as this occurs within 48h of randomization).

inclusion criteria: endotracheal tube or tracheostomy in place and mechanically ventilated for ≤7 days; admitted to a participating icu radiologic evidence of bilateral pulmonary infiltrates not fully explained by pleural effusions, atelectasis, or hydrostatic pulmonary edema p/f ratio <200 with peep ≥8 cm h2o; if abg values are not available, the p/f ratio may be inferred from spo2 values based on table 3 from brown et al as long as following conditions are met: spo2 values are 80-96% spo2 is measured ≥10 min after any change in fio2 peep is ≥ 8 cm h2o the pulse oximeter waveform tracing is adequate the qualifying inferred p/f ratio is confirmed 1-6h after initial determination. access to an lar to provide consent. criteria 3 and 4 must be met within 48h of enrollment and randomization, not be fully explained by hydrostatic pulmonary edema, and must have occurred within 7 days onset of a condition associated with ards. patients may be enrolled and decision about randomization delayed if all criteria other than p/f ratio < 200 are met and then randomized if and when the p/f ratio < 200 (as long as this occurs within 48h of randomization).