La Isla Bonita

肺栓塞（pulmonary embolism），急診必須要隨時想到的急症之一！

常見症狀
喘：75％。
胸痛：66％。
咳嗽：33％。
血痰：13％。

常見徵象
呼吸快（RR↑）：70％。
肺鑼音（rales）：50％。
心跳快（HR↑）：30％。
第四心音（fourth heart sound）：25％。

Well's Score For Pulmonary Embolism
Symptoms of DVT (3 points)
No alternative diagnosis better explains the illness (3 points)
Tachycardia with pulse > 100 (1.5 points)
Immobilization (>= 3 days) or surgery in the previous four weeks (1.5 points)
Prior history of DVT or pulmonary embolism (1.5 points)
Presence of hemoptysis (1 point)
Presence of malignancy (1 point)
7-12：high probability
2-6：moderate probability
0-1：low probability

典型CxR表現
Hampton's hump：wedge-shaped lung infarct/atelectasis after PE，pleural base consolidation，CT上較易看到。
Westermark's sign：vasoconstriction。
專一性高而和特異性很低。

典型EKG表現：S1Q3T3，只發生在20％的個案。專一性和特異性皆低。
S Wave in Lead I
Q Wave in Lead III
T Wave Inversion in Lead III

80％的個案為非特異性的表現
最常見的是竇性頻賣（Sinus tachycardia）
其他表現：
Right sided strain pattern
Right bundle branch block
Right axis deviation
Findings that mimic myocardial infarction
ST segment changes
T Wave changes
Newly onset atrial fibrillation

預後不好的EKG表現
Atrial arrhythmias
Right bundle branch block
Inferior Q-waves
Precordial T-wave inversion and ST-segment changes

診斷
D-dimer（D-dimer低可排除肺栓塞）
EKG
CxR
Spiral CT scan
V/Q scan
Pulmonary angiography

D-dimer
good sensitivity
good negative predictive value
poor specificity
poor positive predictive value

治療
Anticoagulation

比較：Well's Score For Deep Vein Thrombosis
Paralysis, paresis or recent orthopedic casting of lower extremity (1 point)
Recently bedridden (more than 3 days) or major surgery within past 4 weeks (1 point)
Localized tenderness in deep vein system (1 point)
Swelling of entire leg (1 point)
Calf swelling 3 cm greater than other leg (measured 10 cm below the tibial tuberosity) (1 point)
Pitting edema greater in the symptomatic leg (1 point)
Collateral non varicose superficial veins (1 point)
Active cancer or cancer treated within 6 months (1 point)
Alternative diagnosis more likely than DVT (Baker's cyst, cellulitis, muscle damage, SVT, post phlebitic syndrome, ingunal lymphadenopathy, external venous compression) (-2 points)
3-8：high probability
1-2：moderate probability
-2-0：low probability


資料來源：
衛生署台中醫院急診醫學科蔡永隆醫師
Rodger (2000) Am J Cardiol 86:807