Abstract Rationale Primary graft dysfunction (PGD) is a leading cause of early morbidity and mortality after double lung transplantation (DLTx) and shares pathophysiologic features with ventilator-induced lung injury (VILI). Mechanical power (MP), integrating tidal volume, driving pressure, flow, and respiratory rate, quantifies energy delivered to the lungs per unit time. In ARDS, MP 17 J/min is linked to higher mortality and VILI, but whether this threshold applies to ECMO-supported DLTx recipients, who often receive ultra-protective ventilation, is unknown. This study evaluated postoperative MP and time-specific thresholds associated with PGD and other outcomes. Methods We retrospectively analyzed 52 DLTx recipients managed with perioperative ECMO. ECMO was initiated at different time points, including pre-transplant only (11, 21.2%), pre-transplant and continued from the OR (7, 13.5%), initiated in the OR and continued (8, 15.4%), postoperative only (11, 21.2%), and 2+ runs or changes from VV/VA (15, 28.8%). MP and driving pressures were recorded at 1, 25, 49, and 73 hours post-transplant. PGD was defined per ISHLT criteria. ROC analysis determined MP cutoffs optimizing sensitivity and specificity for PGD, and logistic regression evaluated associations with PGD, mortality, and discharge disposition. Results PGD developed in 37 patients (71%). ROC-derived MP thresholds were 15.6 J/min (1h), 15.3 J/min (25h), 11.5 J/min (49h), and 11.9 J/min (73h), all below the 17 J/min ARDS benchmark. Sensitivity and specificity ranged from 59-62% and 43-57%. Patients exceeding these thresholds had higher early PGD incidence. High MP at 49 hours was independently associated with increased mortality (OR 6.48, 95% CI 1.06-39.56) and worse discharge disposition, whereas earlier and later time points were not significantly linked to mortality. Conclusions In ECMO-supported DLTx recipients, postoperative MP thresholds associated with PGD and adverse outcomes are potentially lower than the ARDS standard. Early postoperative MP 15 J/min identifies patients at highest risk, while later thresholds (∼12 J/min) likely reflect ventilator adjustments and evolving clinical status. These findings suggest ARDS-derived MP targets may not directly apply to the post-lung transplant ECMO population, highlighting the need for transplant-specific MP monitoring. Prospective studies are warranted to validate thresholds, and the wide confidence intervals highlight the need for larger cohorts to confirm these findings and guide real-time ventilator management to optimize early graft function. This abstract is funded by: None
Moore et al. (Fri,) studied this question.