肺动脉栓塞的诊治ppt课件

肺动脉栓塞的诊治,制作XGHRH,敬请指正,基本概念,肺栓塞是以各种栓子阻塞肺动脉系统为其发病原因的一组疾病或临床综合征的总称，包括肺血栓栓塞症，脂肪栓塞综合征，羊水栓塞，空气栓塞等。肺血栓栓塞症为来自静脉系统或右心的血栓阻塞肺动脉或其分支所致疾病。肺梗死为肺动脉发生栓塞后，其支配区的肺组织因血流受阻或中断而发生坏死。,肺栓塞的现状,发病率高：仅次于CAD和HBP。易漏诊及误诊：警惕性不高，漏诊率高。不经治疗死亡率高：达20%-30%。明确诊疗者死亡率明显下降：可降至2-8% 。,Epidemiology,There is no accurate data for pulmonary embolism because we has limit knowledge of it. In the United States, it is responsible for about 2.3 new cases per 10,000 persons and 50,000 deaths every year.,流行病学,Arch.Intern.Med.154:861,1994,生存率比较,Arch.Intern.Med.154:861,1994,1.0,1,2,3,Risk Factors for DVT/Pulmonary Embolism （Essential）,Risk Factors for DVT/Pulmonary Embolism （Second）,深静脉血栓形成,肺血栓与深静脉血栓,肺栓塞的大体解剖观,肺栓塞的显微镜下观,肺栓塞的病理生理,肺血管阻塞，神经体液因素或肺动脉压力感受器的作用，引起肺血管阻力增加；肺血管阻塞肺泡死腔气体交换肺泡通气低氧血症V/Q单位气体交换面积二氧化碳刺激性受体反射性兴奋（过度换气）支气管收缩，气道阻力增加肺水肿、肺出血、肺泡表面活性物质减少，肺顺应性降低。,肺栓塞后右心功能不全的病生,肺栓塞,冠状动脉灌注,右心室氧需,右心室壁张力,右心室排血量,右心室氧供,左心室排血量,肺动脉压力右心室后负荷,解剖阻塞 神经体液作用,右心室扩张/功能不全 右心室缺血,室间隔移向左心室,低血压,体循环灌注,左心室前负荷,肺栓塞后肺血流动力学变化,前毛细血管高压 血管床减少 支气管收缩 小动脉血管收缩 侧支血管的形成支气管-肺动脉吻合形成 肺内动静脉分流 血流改变： 血流重分布,Westermark征,呼吸动力学改变,过度通气： 肺动脉高压 顺应性下降 肺不张 气道阻力增加 ： 局限性低碳酸血症 化学介质,临床分型,大面积PE(massive PE)：休克和低血压；动脉收缩压1.5mm、avF有Qs波，但无Qs波QRS轴900或不确定肢导联低电压、avF的T波倒置或V1V4T波倒置,图12000年8月27日（急诊）ECG大致正常,2000年8月29日（门诊）ECG示IRBBB SQTV1V2T波倒置V3V4T波双向,Ventilation/Perfusion Lung Scan,PIOPED：肺扫描分类与肺动脉造影结果的比较,J Nucl Med 1993; 34: 1119,肺扫描,怀疑PE的患者约25可因肺灌注正常而否定诊断，而且不用抗凝治疗可能是安全的怀疑PE的患者约25具有高度的肺扫描结果，他们可能需要行抗凝治疗其余的患者需要进一步的诊断性检查，而这些检查是更广泛的诊断策略,典型肺栓塞,不典型肺栓塞,It is high sensitivity but low specificity,The differential diagnosis for a ventilation perfusion mismatch includes: acute pulmonary embolus previous pulmonary embolus congenital vascular abnormalities vasculitis, bronchogenic carcinoma, radiation therapy,et al.,When a ventilation/perfusion scan does not fit into either the normal or high probability category, then we consider the study to be non-diagnostic and further investigation is required. The majority of cases fall into this category which is characterized by scans with subsegmental defects or defects of any size that match abnormalities on the chest x-ray or the perfusion scan.,A low probability category has been suggested by a number of authors. However, as we can see from the PIOPED data this is not a particularly reliable category. Disagreement among experienced readers is common when perfusion defects are small and limit the utility of this category. This study was originally read as showing a small subsegmental defect. Without the arrow, this study has subsequently been called normal by a number of experienced readers,Conclusion,Lung scans are sensitive exams that essentially rule out the diagnosis of pulmonary embolus when they are normal. Patients with high probability lungs can often be treated without further workup. Those patients with non-diagnostic studies require further diagnostic investigation.,CT of Pulmonary Embolism,Pulmonary infarcts are more readily identified on CT. Modern CT scanners now have faster acquisition times and are providing a detailed assessment of the lung parenchyma that is not available from the chest radiograph. The typical appearance of a pulmonary infarct on CT includes a pleural based density with convex borders and a linear strand at the apex of the triangle,The apex of the triangle is often truncated and not wedge shaped which corresponds to the normal configuration of a secondary lobule in the lung periphery. Low attenuation areas within the infarct represents viable lung. It is important to note, however, that this appearance is not specific for pulmonary infarction. The differential diagnosis for this abnormality includes infarct, hemorrhage, pneumonia, fibrosis, neoplasia and edema,Since the clinical presentation of pulmonary embolus is usually non-specific, the findings on CT are often the first clinical indication that the patient may be suffering from pulmonary embolus. In addition to visualizing the area of infarction we are often able to see the clot itself.,CT has been show to be especially useful in the assessment of patients with chronic dyspnea and known pulmonary artery hypertension. These patients are often difficult to diagnose as is exemplified by this patient with known sclerodema and pulmonary artery hypertension whose CT unexpectedly showed a large calcified clot in the right pulmonary artery.,肺动脉造影,正常肺动脉,This selective study was done because of a perfusion defect in the left lower lobe on a ventilation perfusion scan. The first angiographic study was inconclusive. Therefore, a subselective study was done that demonstrated the clot with certainty.,The most reliable signs of pulmonary embolus are: An Intraluminal filling defect An Abrupt termination of a branch vessel,Conclusion,Angiography is most accurate in segmental and larger sized arteries. The reproducibility of readings is subsegmental and smaller vessels is poor. Angiography is a safe procedure that is most accurate when imaging emboli that lodge in segmental or larger arteries.,The Diagnosis Algorithm,Plasma D-Dimer Assay,Normal to Near-Normal,Low or Intermediate Probability,High Probability,Clinical Assessment,Low Probability,Intermediate or High Probability,Angiography,Positive,Negative, 500mg/L,500mg/L,Ultrasonogram,No DVT,DVT,Lung Scan,Interpretation Criteria,High Probability (80-100% likelihood for PE ):Greater than or equal to 2 large mismatched segmental perfusion defects or the arithmetic equivalent in moderate or large and moderate defects. Intermediate Probability (20-80% likelihood for PE ):1. One moderate to 2 large mismatched perfusion defects or the arithmetic equivalent in moderate or large and moderate defects. 2. Single matched ventilation-perfusion defect with a clear chest radiograph . 3. Difficult to categorize as low or high, or not described as low or high. 4. Nonsegmental perfusion defects (e.g., cardiomegaly, enlarged aorta, enlarged hila, elevated diaphragm). 5. Multiple matched V/Q abnormalities, even when relatively extensive, are low probability for PE . The prevalence of PE in patients with extensive matched V/Q defects and no CXR abnormality was 14% (low probability).,J Nucl Med 1995; 36: 2380-2387,Low Probability (0-19% likelihood for PE ),Perfusion defects matched by ventilation abnormality provided that there are: (a) clear chest radiograph and (b) some areas of normal perfusion in the lungs. Extensive matched V/Q abnormalities are appropriate for low probability, provided that the CXR is clear.Any perfusion defect with a substantially larger chest radiographic abnormality. Any number of small perfusion defects with a normal chest radiograph.,J Nucl Med 1995; 36: 2380-2387,Diagnostic Criteria for Clinically Suspected Pulmonary Embolism,Pulmonary embolism absentNegative pulmonary angiogranNormal or near-normal lung scanD-dimer level500 mg/LPulmonary embolism presentPositive pulmonary angiogramHigh-or intermediate-probability lung scan and ultrasonogram evidence of deep-vein thrombosis,Thorax 51:23, 1996,鉴别诊断,呼吸困难、咳嗽、咯血、呼吸频率增快等呼吸系统表现为主的患者多被诊断为其它的胸肺疾病如肺炎、胸膜炎、肺不张等以胸痛、心悸、心脏杂音、肺动脉高压等循环系统表现为主的患者易衩诊断为其它的心脏疾病如冠心病、风心病等以晕厥、惊恐等表现为主的患者有时被诊断为其它心脏或神经及精神系统疾病如心律失常、脑血管意外、癫痫等,原发性肺动脉高压与肺栓塞复发,相似点：症状：疲乏，活动时呼吸困难最常见，胸痛、昏厥、咯血、紫绀也较常见临床经过：进行性呼吸困难，右心衰竭血流动力学：右心室压力升高、肺毛细血管嵌压正常治疗：包含抗凝治疗,区别点,急性PE的治疗,一般处理：送入监护病房，加强生命体征的监护防止栓子脱落，绝对卧床情感支持对症治疗：如咳嗽、发热等,急性PE,呼吸循环支持治疗,一般患者均采用经鼻导管或面罩吸氧治疗低氧血症无创伤性或经气管插管机械通气治疗呼吸衰竭，避免气管切开。尽量减少正压通气对循环的不种影响。,急性PE,溶栓治疗的适应证,栓塞面积超过2个肺叶血管者合并休克或低血压者合并右心功能不全者排除禁忌证者,急性PE,溶栓禁忌证,绝对禁忌证活动性内出血近期的自发性颅内出血相对禁忌证大手术、分娩、器官活检或不能压迫的血管穿刺史（10天内）2