Mid-America Transplant, St. Louis, Missouri.
Division of Neurocritical Care, Department of Neurology, Washington University School of Medicine in St. Louis, St. Louis, Missouri.
J Heart Lung Transplant. 2021 Feb;40(2):120-127. doi: 10.1016/j.healun.2020.11.014. Epub 2020 Dec 5.
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 [PaO]/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 PaO 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 4 hours (by 113 vs 54 mm Hg, p = 0.001) and remained 74-mm Hg higher at 12 hours (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 PaO 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.
低氧血症是脑死亡（BD）供体器官移植的最常见障碍。在脑死亡后，肺不张是导致低氧血症的主要可逆因素。我们前瞻性评估了 BD 供体在俯卧位通气是否可以逆转肺不张，改善氧合，并使更多的肺被移植。
在一个器官获取组织的康复中心，对 2 年内出现低氧血症（动脉血氧分压[PaO]/吸入氧分数<300mmHg）且有肺不张证据的器官捐献者进行俯卧位通气，持续 12 小时或更长时间。一部分患者接受了 CT 成像，以在俯卧位前后量化肺不张的程度。结果与前 2 年采用类似方法但在仰卧位管理的低氧血症和肺不张的对照组进行了比较。
共有 40 名符合条件的 BD 肺捐献者出现低氧血症和肺不张，采用俯卧位进行管理，并与 79 名采用仰卧位管理的捐献者进行了比较。俯卧位和仰卧位两组的基线 PaO 相似（194±78 与 177±77mmHg，p=0.26），但在俯卧位组 4 小时时增加更多（113 与 54mmHg，p=0.001），12 小时时仍保持 74mmHg 的优势（340 与 266mmHg，p=0.0006）。俯卧位通气后 CT 分级肺不张明显减少，但在仰卧位组仍持续存在（p=0.001）。最终 PaO 并没有显著升高（344 与 306mmHg，p=0.12），但在俯卧位组更多的肺被移植（45%与 24%，p=0.03）。
在 BD 伴低氧血症的供体中，俯卧位通气可逆转肺不张，并迅速且可持续地改善氧合。这种效果似乎转化为更多的肺被移植。
