Donor-size-normalized tidal volume and early peak airway pressure-derived pressure burden after lung transplantation: an exploratory single-center cohort study.

INTRODUCTION: After lung transplantation, the ventilated parenchyma is the donor lung rather than the recipient's native lung. Normalizing tidal volume to donor-predicted body weight (dPBW) indexes delivered ventilation to estimated graft size. METHODS: We conducted a retrospective single-center cohort study to evaluate whether dPBW-normalized tidal volume at intensive care unit admission after transplantation (T0) was associated with time-matched peak pressure difference under clinician-selected ventilation. Peak pressure difference was defined as peak airway pressure minus positive end-expiratory pressure and served as a peak airway pressure-derived pressure-burden metric rather than standard driving pressure. RESULTS: Among 85 adult lung transplant recipients in the primary complete-case analysis, higher T0 dPBW-normalized tidal volume was associated with lower T0 peak pressure difference after enhanced adjustment (β = -0.531, 95% CI -1.031 to -0.032; P = 0.0376). Secondary analyses of dynamic compliance showed an association with higher time-matched dynamic compliance. In contrast, dPBW-normalized tidal volume did not show significant associations with severe primary graft dysfunction, liberation from invasive mechanical ventilation within 28 days, or 30-day mortality after enhanced adjustment. DISCUSSION: These exploratory findings describe associations between dPBW-normalized tidal volume and early peak airway pressure-derived burden under clinician-selected ventilation, but they do not establish a physiologic effect or support changes in ventilatory management. Prospective validation with protocolized ventilation and plateau-pressure measurements is required.