Department of Neurology, Washington University School of Medicine, 660 S Euclid Avenue, Campus Box 8111, St. Louis, MO, 63110, USA.
Department of Neurology, Drexel University College of Medicine, Philadelphia, PA, USA.
Neurocrit Care. 2024 Oct;41(2):576-582. doi: 10.1007/s12028-024-01975-7. Epub 2024 Apr 5.
Hypoxemia is the main modifiable factor preventing lungs from being transplanted from organ donors after brain death. One major contributor to impaired oxygenation in patients with brain injury is atelectasis. Apnea testing, an integral component of brain death declaration, promotes atelectasis and can worsen hypoxemia. In this study, we tested whether performing a recruitment maneuver (RM) after apnea testing could mitigate hypoxemia and atelectasis.
During the study period, an RM (positive end-expiratory pressure of 15 cm HO for 15 s then 30 cm HO for 30 s) was performed immediately after apnea testing. We measured partial pressure of oxygen, arterial (PaO) before and after RM. The primary outcomes were oxygenation (PaO to fraction of inspired oxygen [FiO] ratio) and the severity of radiographic atelectasis (proportion of lung without aeration on computed tomography scans after brain death, quantified using an image analysis algorithm) in those who became organ donors. Outcomes in RM patients were compared with control patients undergoing apnea testing without RM in the previous 2 years.
Recruitment maneuver was performed in 54 patients after apnea testing, with a median immediate increase in PaO of 63 mm Hg (interquartile range 0-109, p = 0.07). Eighteen RM cases resulted in hypotension, but none were life-threatening. Of this cohort, 37 patients became organ donors, compared with 37 donors who had apnea testing without RM. The PaO:FiO ratio was higher in the RM group (355 ± 129 vs. 288 ± 127, p = 0.03), and fewer had hypoxemia (PaO:FiO ratio < 300 mm Hg, 22% vs. 57%; p = 0.04) at the start of donor management. The RM group showed less radiographic atelectasis (median 6% vs. 13%, p = 0.045). Although there was no difference in lungs transplanted (35% vs. 24%, p = 0.44), both better oxygenation and less atelectasis were associated with a higher likelihood of lungs being transplanted.
Recruitment maneuver after apnea testing reduces hypoxemia and atelectasis in organ donors after brain death. This effect may translate into more lungs being transplanted.
低氧血症是防止脑死亡器官捐献者的肺部移植的主要可调节因素。脑损伤患者氧合受损的一个主要原因是肺不张。呼吸暂停试验是脑死亡宣告的一个组成部分，它会促进肺不张，并可能使低氧血症恶化。在这项研究中，我们测试了在呼吸暂停试验后进行肺复张（RM）是否可以减轻低氧血症和肺不张。
在研究期间，在呼吸暂停试验后立即进行 RM（呼气末正压 15cmH2O 持续 15 秒，然后 30cmH2O 持续 30 秒）。我们测量 RM 前后的氧分压（PaO）。主要结局是氧合（PaO 与吸入氧分数[FiO]的比值）和脑死亡后 CT 扫描上的放射性肺不张严重程度（使用图像分析算法量化的无通气肺的比例）在那些成为器官捐献者的患者中。RM 患者的结果与前 2 年进行呼吸暂停试验而没有 RM 的对照组患者进行比较。
在 54 例呼吸暂停试验后进行了 RM，PaO 中位数立即增加了 63mmHg（四分位距 0-109，p=0.07）。18 例 RM 病例出现低血压，但均无生命危险。该队列中有 37 例患者成为器官捐献者，而有 37 例患者进行了没有 RM 的呼吸暂停试验。RM 组的 PaO:FiO 比值更高（355±129 比 288±127，p=0.03），在开始进行供者管理时，更少的患者发生低氧血症（PaO:FiO 比值<300mmHg，22%比 57%；p=0.04）。RM 组的放射性肺不张程度较轻（中位数 6%比 13%，p=0.045）。尽管移植的肺数量没有差异（35%比 24%，p=0.44），但更好的氧合和更少的肺不张与更高的肺移植可能性相关。
呼吸暂停试验后进行 RM 可减少脑死亡后器官捐献者的低氧血症和肺不张。这种效果可能会转化为更多的肺移植。
