Greene R
J Thorac Imaging. 1986 Jul;1(3):31-8. doi: 10.1097/00005382-198607000-00006.
Pulmonary vascular obstruction is most likely to occur in patients with the severest form of ARDS. Obstruction has been ascribed to fibrin thrombosis and to activation of the blood coagulation system, both well-documented in ARDS. The obstruction has been postulated to occur in two stages during post-traumatic ARDS: an initial transient pulmonary vasoconstriction, attributable to platelet and leukocyte aggregation and the release of vasoactive substances; and, two to five days post injury, a more malignant "delayed microembolism" stage, attributable to the development of protein-rich edema and fibrin deposition in the lungs. Bedside balloon occlusion pulmonary angiography, in a single exposure, allows identification of intraluminal filling defects and occlusions of arteries greater than or equal to 1.0 mm in diameter, irregularity and decreased filling of side branch arteries 0.5 to 1.0 mm in diameter, and decreased filling of the pulmonary microvascular background. Plain radiography findings correlate poorly with angiography results, but the mortality rate of patients who exhibit angiographic evidence of obstruction is twice as high as it is in patients with normal angiography.
肺血管阻塞最容易发生在最严重形式的急性呼吸窘迫综合征（ARDS）患者中。阻塞被归因于纤维蛋白血栓形成和血液凝固系统的激活，这在ARDS中都有充分记录。有人推测，创伤后ARDS期间阻塞分两个阶段发生：最初是短暂的肺血管收缩，这归因于血小板和白细胞聚集以及血管活性物质的释放；在受伤后两到五天，进入一个更严重的“延迟性微栓塞”阶段，这归因于肺部富含蛋白质的水肿和纤维蛋白沉积的发展。床边球囊阻塞肺动脉造影在单次曝光下，能够识别管腔内充盈缺损以及直径大于或等于1.0毫米的动脉阻塞、直径0.5至1.0毫米的分支动脉不规则和充盈减少，以及肺微血管背景充盈减少。普通X线摄影结果与血管造影结果相关性较差，但血管造影显示有阻塞证据的患者死亡率是血管造影正常患者的两倍。
