Hyperinflation With Pulmonary Dysfunction in Donor Lungs With Smoking History During Lung Perfusion

Background: Donor lungs with smoking history are perfused in ex vivo lung perfusion (EVLP) to expand donor lung pool. However, the impact of hyperinflation of perfused lungs in EVLP remains unknown. The aim of this study was to investigate the significance of hyperinflation, using an ex vivo measurement delta V_T, during EVLP in smoker's lungs. Materials and methods: Seventeen rejected donor lungs with smoking history of median 10 pack-years were perfused for 2 h in cellular EVLP. Hyperinflation was evaluated by measuring delta V_T = inspiratory − expiratory tidal volume (V_T) difference at 1 h. All lungs were divided into two groups; negative delta V_T (n = 11, no air-trapping pattern) and positive delta V_T (n = 6, air-trapping pattern). Transplant suitability was judged at 2 h. By using lung tissue, linear intercept analysis was performed to evaluate the degree of hyperinflation. Results: The positive delta V_T group had significantly lower transplant suitability than the negative delta V_T group (16 versus 81%, P = 0.035). The positive delta V_T group was significantly associated with lower partial pressure of oxygen/fraction of inspired oxygen ratio ratio (278 versus 356 mm Hg, P = 0.049), higher static compliance (119 versus 98 mL/cm H₂O, P = 0.050), higher lung weight ratio (1.10 versus 0.96, P = 0.014), and higher linear intercept ratio (1.52 versus 0.93, P = 0.005) than the negative delta V_T group. Conclusions: Positive delta V_T appears as an ex vivo marker of ventilator-associated lung hyperinflation of smoker's lungs during EVLP.