Pulmonary Embolism

What is the definition of pulmonary embolism?

Obstruction of pulmonary arterial blood flow, most commonly due to a thrombus from the deep veins, causing impaired oxygenation and hemodynamic instability.

What is the pathophysiology of PE?

DVT embolizes to pulmonary arteries → ventilation-perfusion mismatch → increased pulmonary vascular resistance → possible right heart strain and shock.

What are major risk factors for PE?

• Recent surgery

• Immobilization

• Cancer

• Pregnancy

• OCPs

• Smoking

• Prior DVT/PE

• Hypercoagulable disorders

What are high-yield differentials for PE?

• MI

• Pericarditis

• Aortic dissection

• Arrhythmias

• Pneumothorax

• Pneumonia

• Asthma exacerbation

• Musculoskeletal pain/pleurisy

What are classic symptoms of PE?

• Hemoptysis

• Dyspnea

• Chest pain

• Sudden cough

• Mild fever

• Tachycardia

• Tachypnea

• Hypotension

• Syncope

• +/- signs of DVT

What physical exam findings may suggest PE?

• Tachycardia

• Hypoxia

• Unilateral leg swelling

• Calf tenderness

What ECG findings may occur in PE?

• S1Q3T3 (rare)

• Sinus tachycardia (most common)

• Right heart strain patterns

What laboratory studies are used in PE evaluation?

• CBC

• CMP

• D-dimer

• Troponin

• BNP

Why is D-dimer useful in PE?

High sensitivity

What imaging study is preferred to confirm PE?

CT pulmonary angiogram (CTPA)

What is an alternative imaging study for PE?

V/Q scan (useful if contrast contraindicated).

What additional imaging may be used in PE evaluation?

Doppler ultrasound for DVT.

What cardiac tests evaluate for right heart strain?

• Troponin

• BNP

• Echocardiogram

What is the management disposition for PE?

Admit

What is first-line anticoagulation for PE?

IV heparin to initiate treatment.

What long-term anticoagulation is preferred?

DOAC (apixaban, rivaroxaban).

What is the INR goal if using warfarin?

2.0–3.0

When is embolectomy considered?

High risk for deterioration, substantial clot burden, or significant right ventricular strain.

When are thrombolytics indicated in PE?

Massive PE with cardiopulmonary collapse or severe hemodynamic instability.

What complications can occur from PE?

• Right heart failure

• Shock

• Death

• Recurrent PE

• Pulmonary infarction

What monitoring is required in PE?

Telemetry, oxygenation, hemodynamics, repeat imaging if worsening.

What prevention strategies reduce PE risk?

• Early ambulation

• DVT prophylaxis

• Compression devices

• Anticoagulation when indicated

What is the classic presentation of PE?

Sudden dyspnea, pleuritic chest pain, tachycardia

What condition most closely mimics PE chest pain?

Pneumothorax