肺的脂肪栓塞即肺循环中有颗粒性脂肪小球嵌入。长骨骨折后,多数病人都会发生脂栓,但却大多不致发生脂栓综合征,后者至少应有本综合征的三项主要症状中的一项存在,即呼吸障碍、脑症状或淤点。如接受全髋关节置换术的病人,引流手术区的股静脉中几乎都有微观脂肪栓存在,但都无一发生脂栓综合征。骨盆或下肢长骨骨折病人中,发生明显脂栓综合征的虽仅2％,但约半数病例发生短暂时缺氧血症,并常伴有血小板减少,提示为一亚临床性脂栓综合征。【发病机理】脂栓综合征的发生机理,可能比人们想像的更为复杂,即不仅是骨髓释出脂肪小 Pulmonary fat embolism that is, pulmonary fat particles in the pellet embedding. Most patients have fat embolism after long bone fractures, but most often do not develop lipid embolism syndromes, which should have at least one of the three main symptoms of this syndrome, namely, respiratory disorders, brain symptoms or cramps. For patients undergoing total hip arthroplasty, almost all of the femoral veins in the draining area were present with microscopic fat plugs, but none had lipofection syndrome. In patients with pelvic or lower limb long bone fractures, although only 2% of the patients present with lipid embolism syndrome, brief episodes of hypoxemia and often thrombocytopenia occur in about half of cases, suggesting a subclinical liposarcoma syndrome. Pathogenesis The mechanism of the fat bolt syndrome may be more complicated than one might think, not only in the bone marrow to release small fat