Effects of Positive End-expiratory Pressure and Different Tidal Volumes on Alveolar Recruitment and Hyperinflation

Abstract

Positive end-expiratory pressure promotes alveolar recruitment; increasing Vt above the UIP seems to predominantly increase hyperinflation.

Lung computed tomography during a lung recruitment maneuver in patients with acute lung injury

“…Our data are similar to other studies that have shown, despite different definitions, that only a small fraction of the lung parenchyma is hyperinflated even with high levels of PEEP [1,8,31]. However, it is noteworthy that a small fraction of hyperinflated tissue can have such an impact on lung mechanics.…”

End-expiratory lung impedance change enables bedside monitoring of end-expiratory lung volume change

“…Several authors proposed the monitoring of end-expiratory lung volume as a tool to detect alveolar recruitment during mechanical ventilation [1,3,17].…”

Optimisation of positive end-expiratory pressure by forced oscillation technique in a lavage model of acute lung injury

“…However, these thresholds are arbitrary, and they may influence the estimation of the amount of recruited and hyperinflated volume. We used a cut-off density between the aerated and the over-aerated region of -900 HU, similar to Vieira et al [45] while other groups used cut-off levels of -800 HU [7]. The absolute cut-off may differ due to differences in CT calibration [1] and CT resolution [44].…”