Novel Measurements of Respiratory System Mechanics Demonstrate Important Features of Donor-Recipient Lung Volume Matching That May Link to Subsequent Chronic Lung Allograft Dysfunction

Purpose The effect of matching donor and lung transplant (LTx) recipient lung volumes on LTx outcomes is unknown. The Forced Oscillation Technique (FOT) is a simple measure of the mechanical properties of the respiratory system. We have recently developed novel measures of airway closure using FOT. This study aims to assess the effect of matching donor and recipient lung volumes on respiratory system mechanics using FOT. Methods A multi-centre (Alfred Hospital, Melbourne and St Vincent's Hospital, Sydney) prospective study of (n=19) subjects (63% male, age 56 ±13yrs) at one time point 3-6 months post bilateral LTx were divided into two groups: G1 - Recipient measured pre-LTx total lung capacity (rTLC) predicted dTLC, n=10. All subjects underwent pulmonary function testing including, spirometry, plethysmography and FOT (Tremoflo 2000, Thorasys, Canada). Results In G1, respiratory system elastance (stiffness=AX5) positively correlated with difference between dTLC and rTLC (p Conclusion Novel measurements of respiratory mechanics from FOT demonstrate both oversizing and under-sizing donor TLC can alter recipient respiratory mechanics post-LTx. Longitudinal studies are underway to correlate these effects with the incidence and extent of baseline or chronic lung allograft dysfunction (BLAD & CLAD).