Fig. 2
From: Understanding the mechanisms of ventilator-induced lung injury using animal models
Lung morphology at expiration and inspiration in experimental ARDS, mechanically ventilated with low tidal volume (VT = 6 ml/kg) and progressively increased positive end-expiratory pressure (PEEP). With low VT and low PEEP, aerated lungs (baby lung) are ventilated and collapsed lungs are at rest. With progressive increase in PEEP, at low VT, areas of lung collapse reduce, areas of overdistension increase, and areas of alveolar lung heterogeneity and pendelluft arise; these areas are concentrated around the collapsed units, which present the highest lung stress. At the highest PEEP, the area of lung collapse reduces but even though lung overdistension remains increased, the degree of lung stress and the biological impact on lung tissue reduce because the area associated with pendelluft is no longer observed