|
2010 Mar 15 - Lung Opening and Closing during Ventilation of Acute Respiratory Distress Syndrome |
 |
 |
|
Journal and News Update -
Am J of Respiratory & Critical Care Medicine
|
Pietro Caironi1,2, Massimo Cressoni1, Davide Chiumello2, Marco Ranieri3, Michael Quintel4, Sebastiano G. Russo4, Rodrigo Cornejo5, Guillermo Bugedo5, Eleonora Carlesso1, Riccarda Russo2, Luisa Caspani2 and Luciano Gattinoni1,2. American Journal of Respiratory and Critical Care Medicine Vol 181. pp. 578-586, (2010)
Rationale: The effects of high positive end-expiratory pressure (PEEP) strictly depend on lung recruitability, which varies widely during acute respiratory distress syndrome (ARDS). Unfortunately, increasing PEEP may lead to opposing effects on two main factors potentially worsening the lung injury, that is, alveolar strain and intratidal opening and closing, being detrimental (increasing the former) or beneficial (decreasing the latter).
Objectives: To investigate how lung recruitability influences alveolar strain and intratidal opening and closing after the application of high PEEP.
Methods: We analyzed data from a database of 68 patients with acute lung injury or ARDS who underwent whole-lung computed tomography at 5, 15, and 45 cm H2O airway pressure.
Measurements and Main Results: End-inspiratory nonaerated lung tissue was estimated from computed tomography pressure–volume curves. Alveolar strain and opening and closing lung tissue were computed at 5 and 15 cm H2O PEEP. In patients with a higher percentage of potentially recruitable lung, the increase in PEEP markedly reduced opening and closing lung tissue (P < 0.001), whereas no differences were observed in patients with a lower percentage of potentially recruitable lung. In contrast, alveolar strain similarly increased in the two groups (P = 0.89). Opening and closing lung tissue was distributed mainly in the dependent and hilar lung regions, and it appeared to be an independent risk factor for death (odds ratio, 1.10 for each 10-g increase).
Conclusions: 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.
Weblink here |