Rescue oxygenation Rescue oxygenation methodology may include low-frequency HFO-TGI with cuff leak, prone positioning, inhaled nitric oxide, and extracorporeal membrane oxygenation. The duration of a rescue oxygenation session will be at least 10 hours with allowance for an unlimited extension if PaO2<60 mmHg. Rescue initiation criterion: PaO2<60 mmHg for more than 30 min at FiO2=1.0 during the high-PEEP, lung protective CMV, in the absence of any reversible cardio-respiratory pathology and/or ventilator malfunction.