ARDS · Oxygenation targets
Liberal or Conservative Oxygen Therapy for Acute Respiratory Distress Syndrome
| Design | Randomised trial, stopped early for safety |
|---|---|
| Treatment | Conservative oxygenation, PaO2 55 to 70 mmHg |
| Control | Liberal oxygenation, PaO2 90 to 105 mmHg |
| Population | 201 analysed patients with ARDS |
| Follow-up | 90 days |
| Primary endpoint | Death at 28 days |
| Result | Death at day 28 in 34 of 99 (34.3%) in the conservative-oxygen group versus 27 of 102 (26.5%) in the liberal-oxygen group — difference 7.8 percentage points. The trial was stopped early by the data and safety monitoring board for safety concerns and low likelihood of a significant difference. Five episodes of mesenteric ischaemia occurred in the conservative group. |
| Secondary endpoints | 90-day mortality, mesenteric ischaemia, organ failure |
Among patients with ARDS, early exposure to a conservative-oxygenation strategy with a Pao2 between 55 and 70 mm Hg did not increase survival at 28 days.
The trial authors, in the published abstract
Stopped for safety, with a mortality signal in the wrong direction and five cases of mesenteric ischaemia. It marks the lower bound of permissive hypoxaemia: tolerating a PaO2 in the 50s as a target, rather than as a consequence, is not supported.
Barrot L, Asfar P, Mauny F, et al. Liberal or Conservative Oxygen Therapy for Acute Respiratory Distress Syndrome. N Engl J Med 2020 Mar 12;382(11):999-1008.