肺血栓栓塞

肺血栓栓塞症,概论,肺栓塞(Pulmonary embolism)-栓子阻塞肺动脉系统 (血栓栓塞、脂肪栓塞、羊水栓塞、空气栓塞等)。肺血栓栓塞症(Pulmonary thromboembolism)-来自静脉系统或右心的血栓栓塞肺动脉或其分支。,Fat embolization syndrome occurs most often following trauma with fracture of long bones.,Amniotic fluid embolization can have the same outcome as a large pulmonary embolus.,肺动脉栓塞后，若其支配的肺组织因缺血坏死 -肺梗塞(Pulmonary infarction)。血栓主要来源于下肢深部静脉血栓(Deep venous thrombosis)。,流行病学,肺血栓栓塞症和深静脉血栓形成构成重要医疗保健问题；发达国家发病率0.5-1，为美国死亡率第三位原因；临床表现隐匿，漏诊率和误诊率高。,危险因素,静脉血液淤滞、静脉系统内皮损伤和血液高凝状态；年龄与深部静脉血栓形成和肺血栓栓塞症发病率相关。,原发性危险因素： 遗传因素变异(V因子突变、蛋白C缺乏、蛋白S缺乏和抗凝血酶缺乏)，家族遗传倾向。继发性危险因素： 骨折、创伤、手术、肿瘤、心衰、脑卒中、肥胖、长途旅行、肾病综合症、吸烟、中心静脉插管、血粘滞度增高、妊娠和口服避孕药。,Economy Class Syndrome,The thromboemboli typically originate in the leg veins or pelvic veins of persons who are immobilized.,“Saddle embolus bridges across the pulmonary artery from the heart as it divides into right and left main pulmonary arteries.,The infarct is wedge-shaped and based on the pleura. These infarcts are hemorrhagic because the pulmonary artery carrying most of the blood.,Virchows triadVenous stasis, Venous endothelial injury,Hypercoagulability.,病理生理,血栓来源于下腔静脉（下肢近段深静脉、盆腔静脉丛）、上腔静脉（颈内、锁骨下静脉留置导管）径路或右心房;,Left subclavian vein thrombosis,血栓机械阻塞肺动脉分支，神经体液因素和低氧引起肺动脉收缩，导致肺循环阻力增加；右心室负荷增高-急性肺源性心脏病；右心扩大室间隔左移，左心室排出量下降，导致休克；,栓塞部位肺血流减少，通气/血流比例失调；右房压升高-功能性闭合卵圆孔开放，心内右向左分流；栓塞部位肺泡表面活性物质分泌减少；肺泡萎陷，肺顺应性下降，导致低氧血症、代偿性过度通气；反复发生形成慢性血栓栓塞性肺动脉高压（CTEPH）。,The organization of pulmonary thromboembolus.,临床表现,气促，胸痛（胸膜炎性或心绞痛样疼痛）；晕厥，烦躁不安、惊恐。咯血，咳嗽，心悸（肺梗死三联征）；体征 呼吸急促，发绀，血压下降，哮鸣音或细湿罗音，心动过速；P2亢进，三尖瓣区收缩期杂音，颈静脉充盈；同时注意存在DVT：患肢肿胀、压痛、皮肤色素沉着；肢体周径双侧相差1公分。,The red and swollen thigh and leg caused by thrombus in the deep veins in the groin (ileofemoral veins).,血气示低氧血症、低碳酸血症，肺泡-动脉氧分压差增大；EKG：V1-V4T波倒置，I导联S波+导联Q波+导联T波倒置、右束支传导阻滞、肺型P波、电轴右偏及顺钟向转位；X线：区域性肺纹理变细、右下肺动脉增宽或截断征，肺动脉段膨隆，右心室扩大；尖端指向肺门的楔形阴影；,实验室检查,Electrocardiogram showing transient right bundle branch block in a case of massive pulmonary embolism.,Frontal radiograph of the chest shows an enlarged main pulmonary arteryand a markedly enlarged right and left pulmonary arteries. The peripheral vasculature is normal,Oligemia Diffuse, decreased attenuation throughout the right lung, consistent with oligemia secondary to acute pulmonary embolism.,Pulmonary Infarction Wedge-shaped, subpleural consolidation (Hamptons hump) in the right lower lobe, due to pulmonary infarction.,超声心动图：右心室和（或）右心房扩大；室间隔左移，近端肺动脉扩张，下腔静脉扩张；,The interventricular septum (arrows) into the left ventricle. The left ventricle has assumed a classic D-shaped configuration, indicating impaired left ventricular relaxation.,血浆D-二聚体，急性PTE时升高；,放射性核素肺通气/灌注扫描 肺段分布的肺灌注缺损；,螺旋CT：肺动脉内低密度充盈缺损；磁共振显像（MRI）：MRI肺动脉造影（MRPA）对段以上肺动脉内血栓诊断敏感性和特异性均较高；,CT pulmonary angiography,肺动脉造影为诊断PTE的经典与参比方法。直接征象有肺动脉内造影剂充盈缺损；,Massive pulmonary thromboembolism, seen at pulmonary angiography in a patient with recent resection of colonic cancer, undergoing chemotherapy, who had suddenly collapsed in the ward.,静脉超声、X线静脉造影、CT静脉造影，MRI静脉造影，肢体阻抗容积图，明确是否存在DVT；,鉴别诊断,冠心病：造影见冠脉粥样硬化、管腔阻塞，心肌梗死心电图和心肌酶水平有相应的特征性动态变化。；肺炎：全身感染表现，咯脓性痰、寒战、高热，外周血白细胞显著增高、中性粒细胞比例增高等，抗菌治疗可获疗效；原发性肺动脉高压：无肺动脉腔内占位征，放射性核素肺灌注扫描正常；主动脉夹层：多有高血压，疼痛剧烈，胸片显示纵隔增宽，心血管超声和胸片CT造影检查见主动脉夹层征象。,男性，56岁，右上臂挫伤3天后感胸部不适，气促，氧饱和度下降。,胸片(6月11日),CT（6月12日）显示右肺动脉栓塞。,肺灌注扫描（6月13日）,肺血栓栓塞症临床分型,急性肺血栓栓塞症：1）大面积肺血栓栓塞症:表现为休克；2）非大面积肺血栓栓塞症：部分出现右心功能不全或超声心动图示右心室前壁运动幅度小于5毫米。慢性血栓栓塞性肺动脉高压：慢性进行性肺动脉高压，右心衰竭，影像：肺动脉广泛阻塞，右心导管：肺动脉平均压大于20mmHg。右心室游离壁厚度5mm。,Small peripheral pumonary artery thromboembolus could lead to pulmonary hypertension.,一般处理,监测呼吸、心率、血压、静脉压、心电图及血气的变化；绝对卧床，保持大便通畅，镇静、止通、镇咳；鼻导管或面罩吸氧，纠正低氧血症；右心功能不全应用多巴酚丁胺和多巴胺；,溶栓治疗,适用大面积肺血栓栓塞症，血压和右心室功能均正常不推荐。治疗个体化，溶栓窗14天内。绝对禁忌征：活动性内出血、颅内出血；相对禁忌征：2周内手术、分娩、重度高血压、血小板减少等；尿激酶负荷量4400IU/kg静注，2200IU/kg/h静滴12h。简便方案：20000IU/kg