pulmonary embolism

•Name: 門XX   F/53 

•Present illness：Left chest pain 5 days\No other systemic disease

•Risk factor: Ovarian cyst s/p  operation one year

•Chest CT scan:

Filling defects in Lt pulmonary

trunk, Lt inferior pulmonary

artery & branches 

Hampton sign(+)

•Diagnosis:  

      Pulmonary embolism with Lt

       pleuris and pleural effusion

定義：

1. Pulmonary embolism refers to obstruction of the pulmonary artery or one of its branches by material (eg, thrombus, tumor, air, or fat) that originated elsewhere in the body.

2. Acute vs chronic

3. Massive vs submassive

4. It should be suspected anytime there is hypotension ＋elevated central venous pressure (or neck vein distension), which is not otherwise explained by acute myocardial infarction, tension pneumothorax, pericardial tamponade, or a new arrhythmia.

特別注意：低血壓合併CVP升高（排除掉acute MI, tension PT, pericardiac tamponade時）

機轉：

ØPulmonary arterial obstruction --> platelets release vasoactive agents as serotonin -->­ vascular resistance上升

Ø­alveolar dead space 上升--> V/Q mismatch --> gas exchange下降

ØStimulate irritant receptor -->alveolar hyperventilation(過度換氣！）

ØReflex bronchoconstriction -->airway resistance(氣道阻力又上升）

ØLung edema -->pulmonary compliance下降

Ø ­ RV afterload 上升--> RV dilatation, dysfunction, ischemia

ØIf ASD presence --> prardoxical embolism ® Rt to Lt shunt ® severe arterial hypoxemia

大部份死因：進行性又心衰竭-->cardiac output 下降

血流下降因素：梗塞 休克 懷孕 骨盆腔腫瘤 手術前後靜脈阻塞

易形成血栓：凝血因素 sickle cell diz, protein C, S 缺乏 癌症(adenocarcinoma) 口服避孕藥 , nephrotic syndrome, IBD, antithrombin III deficiency

預測ＰＥ的可能性：

包含的項目：DVT的有無、其他可能診斷、心跳、不動、之前有過DVT or PE、癌症

另外一個發表於內科學期刊的Geneva score

這一分數表多加了年齡、開刀、症狀來預測：症狀有：單側下肢痛、單側下肢靜脈觸痛及單側水腫 此外心跳大於74下就越來越差了

診斷：

Clinical symptoms and signs–Dyspnea, pleuritic pain, tachypnea (R.R.³ 20/min),cough, hemoptysis, tachycardia, rales, phlebitis, increased P2

呼吸困難、肋膜痛、呼吸急促、咳、吐血、心跳快、溼羅音、靜脈炎、P2聲音增強

Laboratory data

–D-dimer

Electrocardiogram：Right ventricular strain with an S1Q3T3

–Nonspecific ST-T wave change

＊＊＊影像診斷：

•Normal radiographic appearances

•Regional oligemia: Westermark sign

•Increase in size of a proximal pulmonary artery: knuckle sign

•Elevated hemidiaphragm

  Associated linear atelectasis

•Focal consolidation (infarcts)

  Usually basal, rarely cavitate

•Pleural effusion

白箭頭間：westermark sign(focal vasoconstriction)