Pulmonary Embolism: Causes, Symptoms, Treatment, and Prevention

Definition

Pulmonary embolism (PE) = obstruction of pulmonary artery(s) by thrombus (usually from deep leg veins) or other material (fat, air, amniotic fluid, tumor).

Risk Factors (Virchow's Triad)

• Stasis: Immobility (surgery, travel, paralysis), heart failure, obesity.
• Hypercoagulability: Cancer, pregnancy, estrogen (OCP/HRT), thrombophilia (Factor V Leiden, prothrombin G20210A), antiphospholipid syndrome.
• Endothelial injury: Trauma, surgery, central lines, vasculitis.

Symptoms

• Dyspnea (most common, sudden).
• Pleuritic chest pain.
• Hemoptysis.
• Tachycardia, hypotension, syncope (massive PE).
• Low-grade fever, anxiety.

Diagnosis

• Wells/PESE score → D-dimer (if low prob) → CTPA (gold standard) or V/Q scan.
• ECHO (RV strain), troponin/BNP (risk stratification).

Treatment

• Anticoagulation (DOACs: apixaban, rivaroxaban; or LMWH → warfarin) – immediate, ≥3 months.
• Thrombolysis (alteplase) for massive PE (hemodynamic instability).
• Surgical/percutaneous embolectomy if thrombolysis contraindicated/failed.
• IVC filter if anticoagulation contraindicated + recurrent PE.

Prevention

• Early mobilization, hydration, compression stockings, pharmacologic prophylaxis (LMWH/DOAC) in hospitalized/surgical patients.
• Weight management, smoking cessation, avoid prolonged sitting.

PE is a medical emergency; early recognition saves lives.