Fig. 1

(from top to bottom): decremental PEEP trials from 15 cmH₂O to 5 cmH₂O (by steps of 2 cmH₂O), at each level of tidal volume (VT). Clinical, respiratory and EIT parameters at VT of 6, 5 and 4 ml/kg of PBW with PEEP set at the best EIT-derived PEEP. The last insert represents percentages of variation in impedance during ventilation (ΔZ) in the right (R) and left (L) half of the lung, and anterior (A) and posterior (P) half of the lung. Δ EELI: end-expiratory lung impedance variation. ECCO₂R: Extracorporeal carbon dioxide removal. P_PLAT: plateau pressure. ΔP: driving pressure defined as the difference between plateau pressure and total PEEP. P_{Lend-insp ER derived}: transpulmonary pressure at end inspiration, computed as follows: P_PLAT x (E_L/E_rs) where E_L is the lung elastance and E_rs the respiratory system elastance; P_Lend-exp: transpulmonary pressure at end expiration C_RS: respiratory system compliance. C_L: lung compliance. C_cw: Chest wall compliance. MP: Mechanical power. EIT: electrical impedance tomography. RVD: Regional ventilatory delay. C loss HP: Compliance loss at high pressure (i.e. overdistention). C loss LP: Compliance loss at low pressure (i.e. collapse)