Effect of donor oxygenation trajectory on lung procurement for transplantation

There is a persistent shortage of donor lungs for transplantation. The relationship between donor PaO₂ trajectory and lung procurement rate is poorly understood.

Demographic and clinical data were abstracted from 4854 brain-dead donors from three US organ procurement organizations between 1/2014 and 6/2020 and from their corresponding lung recipients, if applicable. Donors were first stratified into High versus Low initial PaO₂ then by final PaO₂, using 300 mmHg as the cutoff. Lung procurement rates and corresponding recipient survival between donor groups were studied using multivariable regression and Cox proportional hazard models, respectively.

Over 75% of donors had Low initial PaO₂ (3702/4854). Overall lung procurement rate (LPR, lung donors/all donors) was 32.4% (1574/4854). LPR was greater in the High initial group (40.0% versus 30.1%, p<0.001). In the Low initial group, 1380 (37.3%) donors had High final PaO2, with LPR of 67.9%; frequent bronchoscopy, inotropes, and antibiotics were associated with lung procurement in this group. In the High initial group, 615 (53.4%) donors declined to Low final PaO₂; shorter lengths of stay were associated with lung procurement in this group. Among recipients of High final PaO₂ donor lungs, overall survival was similar regardless of the initial donor PaO₂ (aHR 0.96 [95% CI 0.80-1.15]).

Low initial PaO₂ does not preclude donor lung procurement for transplantation with appropriate donor management. Donor lungs with high initial PaO₂ can deteriorate and may not be procured. Interventions targeted at increasing donor oxygenation may improve lung procurement in brain-dead donors without compromising recipient survival.