Prone positioning in acute respiratory distress syndrome:: a multicenter randomized clinical trial

Objective: We examined the effect on survival of prone positioning as an early and continuous treatment in ARDS patients already treated with protective ventilation. Design and setting: Open randomized controlled trial in 17 medical-surgical ICUs. Patients: Forty mechanically ventilated patients with early and refractory ARDS despite protective ventilation in the supine position. Interventions: Patients were randomized to remain supine or be moved to early (within 48 h) and continuous (>= 20 h/day) prone position until recovery or death. The trial was prematurely stopped due to a low patient recruitment rate. Measurements and results: Clinical characteristics, oxygenation, lung pressures, and hemodynamics were monitored. Need for sedation, complications, length of MV, ICU, and hospital stays, and outcome were recorded. PaO2/FIO2 tended to be higher in prone than in supine patients after 6 h (202 +/- 78 vs. 165 +/- 70 mmHg); this difference reached statistical significance on day 3 (234 +/- 85 vs. 159 +/- 78). Prone-related side effects were minimal and reversible. Sixty-day survival reached the targeted 15% absolute increase in prone patients (62% vs. 47%) but failed to reach significance due to the small sample. Conclusions: Our study adds data that reinforce the suggestion of a beneficial effect of early continuous prone positioning on survival in ARDS patients.