Lung Opening and Closing during Ventilation of Acute Respiratory Distress Syndrome

This study was desgined to determine how lung recruitability influences alveolar strain and intratidal opening and closing after the application of high PEEP. Data from 68 patients with acute lung injury or acute respiratory distress syndrome (ARDS) who underwent whole-lung computed tomography at 5, 15, and 45 cm H2O airway pressure was analysed. In patients with a higher percentage of potentially recruitable lung, the increase in PEEP markedly reduced opening and closing lung tissue, whereas no differences were observed in patients with a lower percentage of potentially recruitable lung. Alveolar strain increased similarly in both groups. The authors concluded that in  ARDS, especially in patients with higher lung recruitability, the beneficial impact of reducing intratidal alveolar opening and closing by increasing PEEP prevails over the effects of increasing alveolar strain.

Caironi P, Cressoni M, Chiumello D, Ranieri M, Quintel M, Russo SG, Cornejo R, Bugedo G, Carlesso E, Russo R, Caspani L  and Gattinoni L. American Journal of Respiratory and Critical Care Medicine 2010; 181: 578-586