Fig. 1

Representative data for a patient with early pulmonary acute respiratory distress syndrome (pneumonia) submitted to incremental positive end-expiratory pressure (PEEP) levels followed by an individualized recruitment maneuver (RM) and a subsequent decremental PEEP titration. The same PEEP levels were applied during the incremental and decremental phases. The patient was ventilated in a volume-controlled mode with a tidal volume of 6 ml/kg (predicted body weight). During the incremental phase, dynamic compliance (Cdyn) responded with an initial increase until PEEP 14 cmH₂O and then remained constant with further incremental steps without any effects on oxygenation. This indicated a lack of any relevant recruitment effect during the incremental steps, which resulted in a constant driving pressure (Driving P). A new mechanical scenario was achieved after lung recruitment, confirmed by the increase in compliance and oxygenation already at the first decremental PEEP steps. As a consequence, ΔP decreased (lower panel, shaded area) despite ventilation at a similar tidal volume. The decreased ΔP was maintained until the beginning of lung collapse during the decremental PEEP steps, evidenced by the fall in oxygenation and compliance. This example illustrates how the modulatory effects of ΔP can be optimized when the mechanical scenario is modified while minimizing lung collapse by recruitment and PEEP titration. Appropriate ethics approval was obtained, as well as appropriate consents to publish from the participant (or legal parent or guardian for children) to report individual patient data. PaO₂ arterial partial pressure of oxygen, Pplat plateau pressure