- Lower extremities DVT found in 70% of patients with PE
- PE is life-threatening in critically ill patients with a 30% mortality rate
Modified Geneva Score
|Surgery/fracture within 1 month||2|
|Previous DVT or PE||3|
|Unilateral lower limb pain||3|
|Pain on deep palpation of lower limb, unilateral edema||4|
|Probability of PE:
- 0–3 points: low probability (8%)
- 4–10 points: intermediate probability (28%)
- ≥11 points: high probability (74%)
- High index of suspicion: Any patient with immobilization with above symptoms should be evaluated
- Intraoperative or postoperative: long bone fracture repair with unexplained symptoms should be evaluated for fat emboli
- Complicated vaginal or Cesarean delivery patients evaluated for amniotic fluid embolization
- EKG: classic signs of right heart strain demonstrated by an S1–Q3–T3 pattern (Figure 206-1) are observed in only 20% of patients with proven PE
- Arterial blood gas shows slight alkalosis and raised alveolar–arterial oxygen gradient
- Increased cardiac markers (BNP, troponin T and I): suggest RV strain; perform echo; discuss thrombolysis
Figure 206-1. Classic EKG Pattern in PE
S wave is apparent in lead I (blue arrowhead), Q wave in lead III (black arrowhead), and inverted T wave in lead III (blue arrow). Reproduced from Knoop KJ, Stack LB, Storrow AB, Thurman RJ. The Atlas of Emergency Medicine. 3rd ed. Figure 23-47B. Available at: http://www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.
- Chest x-ray: usually normal in PE, occasional atelectasis, consolidation, and elevated hemidiaphragm with lung infarcts seen
- CT angiography (CTA) is the initial imaging modality of choice for stable patients, sensitivity 96–100%, specificity 89–98%
- Ventilation–perfusion (V/Q) scans should be used only when CT is not available or if the patient has a contraindication to intravenous contrast; only useful if normal chest x-ray. Preferable if pregnancy (controversial)
- Lower extremities Doppler ultrasound to rule out DVT
- Echocardiography: may demonstrate right ventricular dysfunction in acute PE, predicting a higher mortality and possible benefit from thrombolytic therapy. TEE can visualize large thrombus in pulmonary artery
Figure 206-2. Algorithm If Clinical Suspicion of PE
Initial (O2, Vasopressors If Needed)
- Anticoagulation (AC) reduces mortality and is considered a primary therapy for PE:
- Empiric AC is considered if index of suspicion is high and no contraindication, IV heparin, SC LMWH, or SC fondaparinux can be started before diagnosis is confirmed
- AC reduces the mortality rate of PE because it slows or prevents clot progression and reduces the risk of further ...
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