Ventilation in the prone position improves oxygenation and results in more lungs being transplanted from organ donors with hypoxemia and atelectasis

Abstract

Hypoxemia is the most common barrier to lungs being transplanted from eligible organ donors who are brain dead (BD). Atelectasis is the principal reversible contributing factor to hypoxemia after brain death. We evaluated prospectively whether ventilation in the prone position in donors who are BD would reverse atelectasis, improve oxygenation, and result in more lungs being transplanted. Organ donors managed at the recovery center of 1 organ procurement organization over a 2-year period who exhibited hypoxemia (partial pressure of arterial oxygen [PaO2]/fraction of inspired oxygen of <300 mm Hg) and had evidence of atelectasis were ventilated in the prone position for 12 hours or longer during donor management. A subset underwent computed tomography (CT) imaging to quantify the degree of atelectasis before and after prone positioning. Outcomes were compared with those of a control group with hypoxemia and atelectasis managed similarly but in the supine position in the previous 2 years. A total of 40 lung-eligible donors who were BD with hypoxemia and atelectasis were managed in a prone position and compared with 79 donors in supine position. Baseline PaO2 was similar between the prone and the supine groups (194 ± 78 vs 177 ± 77 mm Hg, p = 0.26) but increased more in the prone group at 4hours (by 113 vs 54 mm Hg, p = 0.001) and remained 74-mm Hg higher at 12hours (340 vs 266 mm Hg, p = 0.0006). CT-graded atelectasis was significantly reduced after ventilation in the prone position but persisted in the supine group (p = 0.001). Final PaO2 was not significantly higher (344 vs 306, p = 0.12), but lungs were more often transplanted in the prone group (45% vs 24%, p = 0.03). Ventilation in the prone position reverses atelectasis and rapidly and sustainably improves oxygenation in organ donors who are BD with hypoxemia. This effect appears to translate into more lungs being transplanted.