Table 2. Effects of changing position from supine on respiratory mechanics and oxygenation in ARDS patients.

Variable	Sitting/upright position	Lateral position	Prone position
Functional residual capacity or end-expiratory lung volume	↑	NA	↑
Respiratory resistance	↓	↑	↓ or →
Respiratory compliance	↑ or →	↓	↑ or →
Lung compliance	NA	↓	↑
Chest wall compliance	NA	↓	↓
Driving pressure	NA	NA	→
Intrinsic PEEP	↓	NA	↓
Work of breathing	↓	NA	NA
Oxygenation	↑	→	↑

↑, increase from the supine position; →, no change from the supine position ↓, decrease from the supine position. ARDS, acute respiratory distress syndrome; NA, not available; PEEP, positive end expiratory pressure.