Effects of transpulmonary mechanical power on lung weight, oxygenation, and lung mechanics in piglets. Black circles represent the 15 piglets ventilated with high tidal volume (approximately 38 ml/kg). Computed tomography (CT) scans of lung weights were available for 13 piglets. Open symbols indicate the nine confirmative experiments (lower tidal volume and higher respiratory rate). Open circles represent piglets ventilated without arterial carbon dioxide control, triangles represent piglets ventilated with arterial carbon dioxide control by variable supplementation. In confirmatory experiments, piglets were intubated with an endotracheal tube with internal diameter of 8 mm, so transpulmonary mechanical power is underestimated in confirmatory experiments in comparison with the main experiments. (A) Lung weights at the start (baseline expiratory CT scan) and at the end of the study (last expiratory CT scan). Δ Lung weight (g) = 69.5 + 14.8 × transpulmonary mechanical power (r² = 0.41, P = 0.001). (B) Pao₂/Fio₂ from the start to the end of the study. Δ Pao₂/Fio₂ = 28.7 − 13.1 × transpulmonary mechanical power (r² = 0.40, P < 0.001). (C) Lung elastance from the start to the end of the study. Δ Lung elastance (cm H₂O/l) = −4.11 + 1.41 × transpulmonary mechanical power (r² = 0.33, P < 0.01).