In vivo isolated lung perfusion: an innovative platform for assessing lung injury propagation in ARDS.

<bold>Background:</bold> In acute respiratory distress syndrome (ARDS), injured alveoli are flooded with fluids laden with inflammatory mediators. The role of these inflammatory biofluids in propagating lung injury when displaced through the airways, namely biofluid-induced lung injury (BILI), has not been fully investigated. <bold>Aim:</bold> To develop a model that completely isolates perfusion (<italic>in vivo</italic> isolated lung perfusion - IVLP) and ventilation of one lung to determine the role of BILI vs bloodstream-related biotrauma in ARDS. <bold>Methods:</bold> Six pigs (54±7kg) underwent independent lung ventilation (ILV) using a dual-lumen tube. Endovascular coiling of the main bronchial artery was performed. The left pulmonary artery and veins were cannulated through a left thoracotomy. IVLP was initiated utilizing an extracorporeal circuit (Fig 1A). <bold>Results:</bold> Study techniques were optimised during the first four experiments. In the last two pigs, ILV and IVLP were successfully achieved. At IVLP start, blood flow was 400mL/min, the left lung was ventilated with FiO2 40%, VT 4mL/kg, RR 5/min, PEEP 5cmH20. Complete isolation of the left lung circulation was confirmed by angiography (Fig 1B). <bold>Conclusion:</bold> This novel IVLP and ILV model paves the way to innovatively investigate ARDS pathways of injury propagation. Future goals involve injuring the isolated lung, followed by controlled dissemination of inflammatory mediators through the airways vs bloodstream. <fig><object-id>erj;64/suppl_68/PA845/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>