Table 3. Key features in the PROSEVA trial on prone positioning in severe acute respiratory distress syndrome (ARDS) patients
1. ARDS criteria confirmed after 12–24 h
2. ARDS with severity criteria:
    PaO2/FIO2 <150 mmHg with FIO2 ≥0.6 + PEEP ≥5 cmH2O + VT 6 ml·kg−1 predicted body weight
3. Several noninclusion criteria
4. Strict lung protective mechanical ventilation (in both groups)
5. First prone position session started within 1 h after randomisation
6. Prone sessions of at least 16 h consecutively
7. Predetermined stopping criteria of prone position
8. Crossover not allowed except as a lifesaving procedure in the supine group
9. Neuromuscular blockade in both groups
10. Centres with expertise in prone positioning for many years
  • PROSEVA: Proning Severe ARDS Patients; PaO2: arterial oxygen tension; FIO2: inspiratory oxygen fraction; PEEP: positive end-expiratory pressure; VT: tidal volume.