肺栓塞的臨床表現(xiàn)與初步診斷

1、肺栓塞的臨床表現(xiàn)與初步診斷,北京協(xié)和醫(yī)院張抒揚,肺栓塞定義,PE：內源性或外源性栓子堵塞肺動脈或其分支引起的肺循環(huán)障礙的臨床病理生理綜合癥，發(fā)生肺出血或壞死者稱肺梗死。,肺栓塞的特點,發(fā)病率高，在心血管疾病中僅次于冠心病和高血壓病易漏診及誤診，國內對PE的警惕性不高，正確診斷率低，漏診率高達80%以上不經治療死亡率高，達20-30%，死亡率占全死亡率原因的第三位，僅次于腫瘤和心肌梗塞診斷明確并經治療者死亡率明顯下降，可降至2-8

2、%,肺栓塞的發(fā)病誘因,創(chuàng)傷骨折中15%患者發(fā)生PE外科術后的深靜脈血栓形成更重要，有50%以上發(fā)生PE長期臥床或不活動（乘機、乘車）慢性心肺疾病、腎病綜合癥惡性腫瘤、血液病肥胖癥、妊娠及口服避孕藥等,肺栓塞的發(fā)病誘因,吸煙性別年齡（每大10歲，PE發(fā)生可能性增高3倍）遺傳缺陷-抗ATⅢ缺陷、遺傳性凝血異常、纖溶酶原缺乏、有關凝血因子突變等,肺栓塞的臨床類型,PE的臨床譜廣取決于PE的范圍和 心肺功能狀態(tài)1-2個肺段栓

3、塞無癥狀，到十幾個肺段栓塞引起急性肺原性心臟病，甚至猝死,肺栓塞的臨床類型,常見的臨床類型：猝死型急性肺原性心臟病型不能解釋的呼吸困難型肺梗死型慢性栓塞性肺動脈高壓型,肺栓塞的典型臨床表現(xiàn),癥狀（三聯(lián)征）：呼吸困難胸痛咯血患者不到1/3， 多數(shù)僅有一兩個癥狀，以原因不明的勞力性呼吸困難最為常見,肺栓塞的臨床表現(xiàn),體征：（不能忽視）呼吸次數(shù)（>20次/分）心率次數(shù)（>100次/分）頸靜脈充盈、搏動（反

4、映右心室負荷增加）下肢靜脈檢查（患肢淺靜脈擴張、僵硬度增加、腫脹，若一側大腿或小腿周徑較對側大1公分，即有診斷意義）,肺栓塞的診斷,一般講，有癥狀的PE通常會出現(xiàn)某種程度的實驗室檢查改變，如X-線胸片、心電圖、UCG及動脈血氣等，據(jù)此可做出初步的診斷,肺栓塞的心電圖表現(xiàn),非特異性，非診斷性，但卻有價值。急性PE的心電圖變化的病理生理學基礎：急性右心室擴張，其心電圖變化常是一過性的，多變的，需動態(tài)比較觀察。,肺栓塞的心電圖表現(xiàn),常

5、見的心電圖表現(xiàn)：電軸右偏SⅠQⅢTⅢ型（Ⅰ導聯(lián)S波變深，>1.5mm即有意義，Ⅲ導聯(lián)出現(xiàn)q波和T波倒置）右心前導聯(lián)V1-2及Ⅱ、Ⅲ、aVF T波倒置即有意義順鐘向轉位至V5；完全性或不完全性右束枝傳導阻滯，有時僅有V1-V3R-5RS波粗頓、挫折。,肺栓塞的心電圖表現(xiàn),急性PE的心電圖改變是一柄“雙刃劍”，用得好有助與PE的診斷，反之，將誤診為其他心臟病，如冠心病、心肌炎等。應結合臨床加以判斷。,肺栓塞的胸片表現(xiàn),

6、有癥狀的PE患者胸X-線平片可能正常，但多有改變，如區(qū)域性肺血減少或肺血分布不均；肺容積縮小，患側膈肌抬高；肺陰影不多見，對肺部陰影伴或不伴咯血，或伴胸腔積液者，在鑒別診斷中要考慮到肺梗死的可能。,肺栓塞的超聲心動圖表現(xiàn),直接征象：肺動脈主干及其左右分支栓塞間接征象：右室擴大，室間隔左移，左室 變小，呈D字形，右室運動減弱，肺動脈增寬，三尖瓣返流及肺動脈高壓,肺栓塞的V/Q核素檢查,High-probability sc

7、an Nondiagnostic scanIntermediate-probability scanLow-probability scanVery-low-probability scanNormal scan,肺栓塞的V/Q核素檢查,Normal ventilation and perfusion lung scans(V/Q)rule out PE. A normal scan shows no perfusion

8、 defects, with normal lung outlines on the chest x-ray.,肺栓塞的V/Q核素檢查,A high -probability scan is defined as a scan showing the following:>2 large segmental perfusion defects without ventilation or chest x-ray abnorma

9、lities;or one large segmental perfusion defect and >=2 moderate segmental perfusion defects and normal ventilation;or >=4 moderate segmental perfusion defects and normal ventilation.,肺栓塞的V/Q核素檢查,An intermediate-p

10、robability scan is definedas one which has the following:1 moderate or <=2 large segmental perfusion defects with normal ventilationV/Q defects and chest x-ray parenchymal opacity in the lower lung;,肺栓塞的V/Q核素檢查,An

11、intermediate-probability scan is definedas one which has the following:sing moderate matched V/Q defects with normal chest x-ray findings;V/Q defects and small pleural effusions; and scan that is difficult to categori

12、ze as a normal-,low-,or high-probability scan.,肺栓塞的V/Q核素檢查,An low-probability scan is defined as onewhich has the following:multiple matched V/Q defects, regardless of size, with normal chest x-ray findings;correspond

13、ing V/Q defects and chest x-ray parenchymal opacity in upper or middle lung zone; corresponding V/Q defects and large pleural effusion;,肺栓塞的V/Q核素檢查,any perfusion defects with substantially larger chest x-ray abnormality;

14、defects surrounded by normally perfused lung (stripe sign)>3 small (<25% of segment) segmental perfusion defects with a normal chest x-raynonsegmental perfusion defects(cardiomegaly, aortic impression, enlarged

15、hila),肺栓塞的V/Q核素檢查,A very -low-probability scan is defined as having <=3 small (<25% of segment) segmental perfusion defects with a normal chest x-ray.,肺栓塞的可能性,Scan CategoryProbability of PE(%) High87Int

16、ermediate30Low14,JAMA 1990;263:2753-2759,肺栓塞的其他檢查,血氣分析：PaCO2減少，pH升高，伴有或不伴PaO2下降，均有利于PE的診斷。血清D-二聚體測定<5ug/L，有除外急性PE的意義。對下肢深靜脈血栓的檢查（是診斷PE的重要標志）,肺栓塞的其他檢查,對下肢深靜脈血栓的檢查（是診斷PE的重要標志）：靜脈造影血管彩色多普勒放射性核素靜脈造影下肢阻抗容積波