Shih W J, Pulmano C
Nuclear Medicine Service, Veterans Affairs Medical Center, Lexington, KY, USA.
Clin Nucl Med. 1996 Jun;21(6):465-8. doi: 10.1097/00003072-199606000-00007.
Massive pulmonary embolism is defined as an anatomic obstruction of 50% or more of the pulmonary artery. A reduction of at least 50% of the cross-sectional area of the pulmonary artery causes significant hemodynamic instability and marked hypoxia exhibiting syncope, apprehension, hypotension, diaphoresis, chest pain, altered mental status, and shortness of breath. A patient, who had no definite clinical signs and symptoms, was demonstrated to have massive pulmonary embolism by extensive mismatched ventilation-perfusion defects scintigraphically and confirmed as thromboemboli in the main pulmonary arteries on a standard CT of the thorax. The lack of clinical manifestations of massive pulmonary embolism might be related to the insidious onset and progressive formation of thromboembolism. The patient gradually adapted to and/or compensated for hemodynamic changes.
大面积肺栓塞定义为肺动脉50%或更多的解剖学阻塞。肺动脉横截面积减少至少50%会导致显著的血流动力学不稳定和明显的低氧血症，表现为晕厥、焦虑、低血压、出汗、胸痛、精神状态改变和呼吸急促。一名无明确临床体征和症状的患者，通过广泛的不匹配通气-灌注缺损闪烁显像被证明患有大面积肺栓塞，并在胸部标准CT上证实为主要肺动脉内的血栓栓塞。大面积肺栓塞缺乏临床表现可能与血栓栓塞的隐匿性发作和逐渐形成有关。患者逐渐适应和/或代偿了血流动力学变化。
