Miniati M, Pistolesi M, Monti S, Giuntini C
C.N.R. Instituto di Fisiologia Clinica, Universitá di Pisa, Italy.
Appl Cardiopulm Pathophysiol. 1991;4(1):55-62.
ARDS is still characterized by an exceedingly high mortality rate. Methods are then needed to detect ARDS at the earliest clinical stage. Over the last decade, radioisotopic techniques have developed, aimed at demonstrating an abnormal neutrophil sequestration in the lung or detecting functional alterations of the pulmonary alveolar-capillary barrier, which likely precede the onset of respiratory distress. Preliminary application of these techniques in patients with ARDS yielded conflicting results in terms of sensitivity and specificity. On the contrary, lung vascular abnormalities have been consistently observed in patients with ARDS studied by perfusion lung scanning. They consist of focal, non segmental perfusion defects, mostly peripheral and dorsal, with redistribution of blood flow to non-dependent lung regions. This scintigraphic pattern may be considered typical of ARDS since it is not observed in other acute lung disorders. Perfusion abnormalities on lung scans are detectable from the very early stage of ARDS and correlate with the severity of the syndrome as reflected by gas exchange, central hemodynamics, and chest radiography. Perfusion lung scanning may then be used in the early detection and evaluation of vascular injury in ARDS.
急性呼吸窘迫综合征（ARDS）的死亡率仍然极高。因此需要在临床最早期阶段检测出ARDS的方法。在过去十年中，放射性同位素技术得到了发展，旨在证明肺部存在异常的中性粒细胞滞留或检测肺泡-毛细血管屏障的功能改变，这些改变可能在呼吸窘迫发作之前出现。这些技术在ARDS患者中的初步应用在敏感性和特异性方面产生了相互矛盾的结果。相反，通过灌注肺扫描研究的ARDS患者中一直观察到肺部血管异常。这些异常表现为局灶性、非节段性灌注缺损，主要位于周边和背部，同时血流重新分布至非下垂肺区。这种闪烁扫描模式可被视为ARDS的典型表现，因为在其他急性肺部疾病中未观察到。肺扫描上的灌注异常在ARDS的极早期阶段即可检测到，并且与综合征的严重程度相关，这可通过气体交换、中心血流动力学和胸部X线摄影反映出来。因此，灌注肺扫描可用于ARDS血管损伤的早期检测和评估。
