Figure 1

Measurement of positive end-expiratory pressure (PEEP)-induced alveolar recruitment using the pressure–volume (PV) curve. The PV curves of the respiratory system recorded from zero end-expiratory pressure (ZEEP) and from PEEP are superimposed on a common volume axis. '0' volume corresponds to the end-expiratory lung volume (EELV) on ZEEP. The first point of the PEEP PV curve corresponds to the increase in EELV induced by PEEP (Δ EELV). On this example, the recruitment induced by PEEP is measured at a pressure of 20 cmH₂O.