Impact of Donor Arterial Partial Pressure of Oxygen on Outcomes After Lung Transplantation in Adult Cystic Fibrosis Recipients

Introduction: Donor P_aO₂ levels are used for assessing organs for lung transplantation (LTx), but survival implications of P_aO₂ levels in adult cystic fibrosis (CF) patients receiving LTx are unclear. Methods: UNOS registry data spanning 2005–2013 were used to test for associations of donor P_aO₂ with patient survival and bronchiolitis obliterans syndrome (BOS) in adult (age ≥ 18 years) first-time LTx recipients diagnosed with CF. Results: The analysis included 1587 patients, of whom 1420 had complete data for multivariable Cox models. No statistically significant differences among donor P_aO₂ categories of ≤200, 201–300, 301–400, or >400 mmHg were found in univariate survival analysis (log-rank test p = 0.290). BOS onset did not significantly differ across donor P_aO₂ categories (Chi-square p = 0.480). Multivariable Cox models of patient survival supported the lack of difference across donor P_aO₂ categories. Interaction analysis found a modest difference in survival between the two top categories of donor P_aO₂ when examining patients with body mass index (BMI) in the lowest decile (≤16.5 kg/m²). Conclusions: Donor P_aO₂ was not associated with survival or BOS onset in adult CF patients undergoing LTx. Notwithstanding statistically significant interactions between donor P_aO₂ and BMI, there was no evidence of post-LTx survival risk associated with donor P_aO₂ below conventional thresholds in any subgroup of adults with CF.