Fig. 2.

Respiratory variables, distribution of ventilation, and ‘silent spaces’ in Case 2

(A) High PEEP, Supine; (B) Low PEEP, Supine; (C) High PEEP, Prone; and (D) Low PEEP, Prone. Regardless of position, the amount of ‘

silent spaces’

in non-dependent lung increased, oxygenation deteriorated, and respiratory system compliance reduced by increasing PEEP, suggesting PEEP induced overdistension, (A, C). Prone position at low PEEP had the least amount of ‘silent spaces’ in non-dependent lung, achieving the highest value of oxygenation (D). PEEP = positive end-expiratory pressure; Crs = respiratory system compliance.