人工呼吸器関連肺傷害のリスクを可視化する革新的な技術：肺ストレスマッピング

Conventional monitoring of acute respiratory distress syndrome (ARDS) relies on global parameters, e.g., tidal volume, airway pressure, and driving pressure. These parameters do not capture regional stress heterogeneity within the lung.

To develop and validate a novel technique, lung stress mapping visualizing regional lung stress throughout the lung, and to evaluate its biological and clinical relevance.

Lung stress mapping combines esophageal pressure and plateau pressure with CT-derived pleural pressure gradients to generate spatially resolved maps of inspiratory transpulmonary pressure. Accuracy was tested in pigs by surgically inserted pleural sensors. Biological relevance was assessed in rabbits by correlating lung stress mapping-derived parameters with regional proinflammatory cytokine expression. Clinical feasibility and associations with outcome were evaluated in 20 consecutive ARDS patients enrolled in a prospective study.

Good correlation and agreement between sensor-derived and mapping-derived lung stress were confirmed. In rabbits, lung inflammation predominantly occurred in nondependent lung regions where lung stress was higher, and overall inflammation correlated with lung stress mapping-derived parameters. In ARDS patients, all received lung-protective ventilation. Non-survivors had significantly higher lung stress mapping-derived maximum and mean lung stress than survivors, despite similar global ventilatory parameters. Exploratory ROC analyses showed stronger associations of lung stress mapping-derived parameters with 90-day mortality than driving pressure.

Lung stress mapping accurately quantified regional transpulmonary stress and revealed biologically and clinically meaningful heterogeneity. This technique may help identify patients with ARDS at increased risk of ventilator-induced lung injury who would not be recognized through conventional respiratory monitoring.