肺動(dòng)脈栓塞的診治

1、肺動(dòng)脈栓塞的診治制作XGHRH敬請(qǐng)指正基本概念肺栓塞肺栓塞是以各種栓子阻塞肺動(dòng)脈系統(tǒng)為其發(fā)病原因的一組疾病或臨床綜合征的總稱，包括肺血栓栓塞癥，脂肪栓塞綜合征，羊水栓塞，空氣栓塞等。肺血栓栓塞癥肺血栓栓塞癥為來(lái)自靜脈系統(tǒng)或右心的血栓阻塞肺動(dòng)脈或其分支所致疾病。肺梗死肺梗死為肺動(dòng)脈發(fā)生栓塞后，其支配區(qū)的肺組織因血流受阻或中斷而發(fā)生壞死。肺栓塞的現(xiàn)狀發(fā)病率高高：僅次于CAD和HBP。易易漏診及誤診：警惕性不高，漏診率高。不經(jīng)治療死亡率高高：達(dá)20%-30%。明確診療者死亡率明顯下降下降：可降至2-8% 。 EpidemiologyThere is no accurate data for pulm

2、onary 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.流行病學(xué)0 01 12 23 34 46569656970747074757975798084808485898589年齡（歲）年齡（歲）發(fā)生率/ 1 0 00患 者 -年發(fā)生率/ 1 0 00患 者 -年DVTDVTPEPEArch.Intern.Med.154:86

3、1,1994生存率比較Arch.Intern.Med.154:861,1994隨訪的年數(shù)隨訪的年數(shù)生存的可能性生存的可能性匹配的樣本匹配的樣本DVTDVTPEPE1.0123Risk Factors for DVT/Pulmonary Embolism （Essential）抗凝血酶缺乏蛋白C缺乏先天性異常纖維蛋白原血癥V因子基因突變血栓調(diào)節(jié)蛋白纖溶酶原缺乏高半胱氨酸血癥異常纖溶酶原血癥抗心肌堿脂抗體蛋白S缺乏纖溶酶原激活抑制劑過(guò)量因子缺乏前凝血酶20210A突變Risk Factors for DVT/Pulmonary Embolism （Second）創(chuàng)傷/骨折外科手術(shù)卒中制動(dòng)高齡惡性腫

4、瘤+化療中心靜脈導(dǎo)管肥胖慢性靜脈機(jī)能不全心力衰竭吸煙長(zhǎng)途旅行妊娠/產(chǎn)后期口服避孕藥克隆病、狼瘡抗凝劑腎病綜合征假體表面粘滯性過(guò)高血小板異常深靜脈血栓形成原因 分類血流滯緩小腿肌肉靜脈叢血栓形成髂股靜脈血栓形成靜脈壁損傷原發(fā)性髂肌靜脈血栓形成繼發(fā)性髂股靜脈血栓形成高凝狀態(tài)股青腫肺血栓與深靜脈血栓肺栓塞的大體解剖觀肺栓塞的顯微鏡下觀肺栓塞的病理生理肺血管阻塞，神經(jīng)體液因素或肺動(dòng)脈壓力感受器的作用，引起肺血管阻力增加；肺血管阻塞肺泡死腔氣體交換肺泡通氣低氧血癥V/Q單位氣體交換面積二氧化碳刺激性受體反射性興奮（過(guò)度換氣）支氣管收縮，氣道阻力增加肺水腫、肺出血、肺泡表面活性物質(zhì)減少，肺順應(yīng)性降低。肺栓

5、塞后右心功能不全的病生肺栓塞冠狀動(dòng)脈灌注右心室氧需右心室壁張力右心室排血量右心室氧供左心室排血量肺動(dòng)脈壓力右心室后負(fù)荷解剖阻塞 神經(jīng)體液作用右心室擴(kuò)張/功能不全 右心室缺血室間隔移向左心室低血壓體循環(huán)灌注左心室前負(fù)荷肺栓塞后肺血流動(dòng)力學(xué)變化 前毛細(xì)血管高壓 血管床減少 支氣管收縮 小動(dòng)脈血管收縮 側(cè)支血管的形成支氣管-肺動(dòng)脈吻合形成 肺內(nèi)動(dòng)靜脈分流 血流改變： 血流重分布 Westermark征呼吸動(dòng)力學(xué)改變 過(guò)度通氣： 肺動(dòng)脈高壓 順應(yīng)性下降 肺不張 氣道阻力增加 ： 局限性低碳酸血癥 化學(xué)介質(zhì) 臨床分型大面積PE(massive PE)：休克和低血壓；動(dòng)脈收縮壓 3 8.5C體溫 3 8.

6、5C喘息喘息Homans征Homans征右室抬舉右室抬舉胸膜磨擦音胸膜磨擦音第三心音第三心音紫紺紫紺D-二聚體分析檢驗(yàn)方法病人數(shù)PE發(fā)生率% 敏感性 特異性ELISA1579349843快速 ELISA6352410044傳統(tǒng)乳膠試驗(yàn)364469255血乳膠試驗(yàn)140259763Adapted from Bounameaux et al, 1997 肺栓塞胸片檢查0 01010202030304040505060607070發(fā)生率%發(fā)生率%正常正常肺不張或?qū)嵶兎尾粡埢驅(qū)嵶冃厍环e液胸腔積液胸膜肥厚胸膜肥厚縱隔上抬縱隔上抬肺動(dòng)脈搏增寬肺動(dòng)脈搏增寬Westermark征Westermark征心臟增大

7、心臟增大肺水腫肺水腫Peer Review Status: Externally Peer Reviewed by the AMAX-RAY FOR CHESTAtelectasis and parenchymal densities are quite common. The areas of atelectasis are more common in the lower lobe as are the areas of parenchymal densityMost of these densities are caused by pulmonary hemorrhage and ede

8、ma and can be confused with infectious infiltrates or malignant massesPleural effusions are common and most often unilateral despite the fact that most clots are bilateral. These effusions are usually visible when the patient seeks medical attention. They are almost always small, occupying less than

9、 15% of a hemithorax and rarely increase in size after 3 days. Any increase in size after 3 or 4 days should raise the suspicion of a pulmonary infection or re-embolization. Pleural based opacities with convex medial margins are also known as a Hamptons Hump. This may be an indication of lung infarc

10、tion. However, that rate of resolution of these densities is the best way to judge if lung tissue has been infarcted. Areas of pulmonary hemorrhage and edema resolve in a few days to one week. The density caused by an area of infarcted lung will decrease slowly over a few weeks to months and may lea

11、ve a linear scar. A diaphragm may be elevated, reflecting volume loss in the affected lung. The central pulmonary arteries may be prominent either from pulmonary hypertension or the presence of clot in those arteries. Cardiomegally is a non-specific finding but may imply an enlarged right ventricle

12、as seen in the patient who presented with large bilateral pulmonary emboli. A Westermarks sign implies an area of decreased vascularity and perfusion accompanied by an enlarged central pulmonary artery on the affected side. 肺栓塞的心動(dòng)超聲征象直接看到血栓右室擴(kuò)張右室活動(dòng)減弱室間隔異?；顒?dòng)三尖瓣反流速度增快肺動(dòng)脈擴(kuò)張無(wú)吸氣性下腔靜脈塌陷減弱Br.Heart.J.1994,7

13、2:52室間隔異?；顒?dòng)舒張期收縮期Color-Flow-Doppler-ultrasound非擠壓性充盈缺損心電圖表現(xiàn)不完全性或完全性右束支傳導(dǎo)阻滯、avL的S波1.5mm、avF有Qs波，但無(wú)Qs波QRS軸900或不確定肢導(dǎo)聯(lián)低電壓、avF的T波倒置或V1V4T波倒置圖12000年8月27日（急診）ECG大致正常2000年8月29日（門診）ECG示IRBBB SQTV1V2T波倒置V3V4T波雙向Ventilation/Perfusion Lung ScanPIOPED：肺掃描分類與肺動(dòng)脈造影結(jié)果的比較肺掃描肺栓塞肺動(dòng)脈造影陰性總數(shù)有無(wú)不肯定高度可疑1021417124中度可疑1052179

14、33364低度可疑391991262312接近正常/正常550274131總計(jì)25148024176931J Nucl Med 1993; 34: 1119懷疑PE的患者約25可因肺灌注正常而否定診斷，而且不用抗凝治療可能是安全的懷疑PE的患者約25具有高度的肺掃描結(jié)果，他們可能需要行抗凝治療其余的患者需要進(jìn)一步的診斷性檢查，而這些檢查是更廣泛的診斷策略典型肺栓塞 不典型肺栓塞It is high sensitivity but low specificity The differential diagnosis for a ventilation perfusion mismatch inc

15、ludes: 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

16、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 author

17、s. 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 ar

18、row, this study has subsequently been called normal by a number of experienced readersConclusionLung 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 pa

19、tients with non-diagnostic studies require further diagnostic investigation. CT of Pulmonary EmbolismPulmonary 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 th

20、e 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 l

21、obule 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

22、and edemaSince 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 h

23、as 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 lar

24、ge calcified clot in the right pulmonary artery. 肺動(dòng)脈造影正常肺動(dòng)脈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 certa

25、inty. The most reliable signs of pulmonary embolus are: vAn Intraluminal filling defect vAn Abrupt termination of a branch vessel ConclusionAngiography is most accurate in segmental and larger sized arteries. The reproducibility of readings is subsegmental and smaller vessels is poor. Angiography is

26、 a safe procedure that is most accurate when imaging emboli that lodge in segmental or larger arteries. The Diagnosis Algorithm Plasma D-Dimer AssayNormal to Near-NormalLow or Intermediate ProbabilityHigh ProbabilityClinical AssessmentLow ProbabilityIntermediate or High ProbabilityAngiographyPositiv

27、eNegative 500mg/L 500mg/LUltrasonogramNo DVTDVTLung ScanInterpretation CriteriaHigh 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

28、% 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 h

29、igh. 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 abnormali

30、ty was 14% (low probability). J Nucl Med 1995; 36: 2380-2387Low 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

31、 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: 2380-2387Diagnostic Criteria for Clinically Suspected Pulmonary

32、 EmbolismPulmonary embolism absentNegative pulmonary angiogranNormal or near-normal lung scanD-dimer level50女女/男比例男比例4：11：1臨床經(jīng)過(guò)臨床經(jīng)過(guò)進(jìn)行性惡化進(jìn)行性惡化穩(wěn)定一段時(shí)間后惡化穩(wěn)定一段時(shí)間后惡化肺灌注掃描肺灌注掃描無(wú)節(jié)段性灌注缺損無(wú)節(jié)段性灌注缺損節(jié)段性或大片灌注缺損節(jié)段性或大片灌注缺損肺動(dòng)脈收縮壓肺動(dòng)脈收縮壓60mmHg60mmHg肺動(dòng)脈造影肺動(dòng)脈造影“修剪修剪”征征管腔內(nèi)充盈缺損管腔內(nèi)充盈缺損肺動(dòng)脈造影混淆肺動(dòng)脈造影混淆的問(wèn)題的問(wèn)題血栓血栓“修剪修剪”征也提示征也提示PE確診確診肺活檢肺活檢肺血管鏡肺血管鏡治療治療抗凝；大劑量硝苯地平及靜抗凝；大劑量硝苯地平及靜注前列環(huán)素注前列環(huán)素抗凝；抗凝；IVC中斷；血栓中斷；血栓動(dòng)脈內(nèi)膜切除術(shù)動(dòng)脈內(nèi)膜切除術(shù)急性PE的治療一般處理：送入監(jiān)護(hù)病房，加強(qiáng)生命體征的監(jiān)護(hù)防止栓子脫落，絕對(duì)臥床情感支持對(duì)癥治療：如咳嗽、發(fā)熱等急性急性PE呼吸循環(huán)支持