What are the symptoms and treatment of pulmonary embolism?

Pulmonary Embolism: Symptoms and Treatment

Pulmonary embolism (PE) presents most commonly with dyspnea (80% of cases), chest pain (52%), and syncope (19%), and requires prompt anticoagulation with heparin or direct oral anticoagulants as the mainstay of treatment to reduce mortality and morbidity. 1, 2

Clinical Presentation

Common Symptoms

• Dyspnea: Most frequent symptom (80% of cases)
  • May be acute and severe in central PE
  • Can be mild and transient in peripheral PE 1
• Chest pain (52% of cases)
  • Pleuritic pain: Usually indicates peripheral emboli causing pulmonary infarction
  • Angina-like substernal pain: May reflect right ventricular ischemia in central PE 1, 3
• Syncope (19% of cases): Important warning sign that may indicate central PE with severe hemodynamic compromise 1
• Hemoptysis (5-7% of cases): Associated with pulmonary infarction 4

Common Signs

• Tachypnea (respiratory rate >20/min): Present in 70% of cases
• Tachycardia (heart rate >100/min): Present in 26% of cases
• Fever (>38.5°C): Present in 7% of cases
• Cyanosis: Present in 11% of cases 1
• Signs of hemodynamic instability: Hypotension, oliguria, cold extremities (in severe cases) 3

Important Clinical Considerations

• No single symptom or sign can reliably confirm or exclude PE 1
• Normal oxygen saturation does not rule out PE (up to 40% of patients have normal arterial oxygen saturation) 1
• In patients with pre-existing cardiopulmonary disease, PE may present only as worsening of baseline dyspnea 1
• Approximately 10% of PE cases are "silent" and discovered incidentally 1, 4
• The combination of sudden onset dyspnea, chest pain, syncope, or hemoptysis is reported in 94% of PE cases 4

Classification of PE Severity

High-Risk PE (Massive)

• Characterized by hemodynamic instability
• Presents with shock or persistent arterial hypotension
• Requires immediate aggressive intervention 3

Non-High-Risk PE

• Further stratified by assessing:
  • Right ventricular dysfunction
  • Myocardial injury markers 3
• Includes intermediate-risk (submassive) and low-risk categories 5

Treatment

Anticoagulation

• Mainstay of treatment for all objectively confirmed PE cases 2, 6
• Initial options:
  • Heparin (intravenous or subcutaneous)
    • Initial dose: 5,000 units IV, followed by 10,000-20,000 units subcutaneously every 8-12 hours
    • Adjust dosage to maintain aPTT at 1.5-2 times normal 2
  • Direct Oral Anticoagulants (DOACs)
    • Preferred for most patients due to safety profile 6

Duration of Treatment

• Minimum 3 months of anticoagulation for all PE cases
• Consider indefinite anticoagulation for:
  • Unprovoked PE
  • Recurrent PE
  • Ongoing risk factors
  • Patients with acceptable bleeding risk 6

Additional Treatments for High-Risk PE

• Thrombolytic therapy: For patients with hemodynamic instability
• Mechanical thrombectomy: When thrombolytics are contraindicated 3

Long-Term Complications

• Chronic thromboembolic pulmonary hypertension (CTEPH):
  • Rare but associated with significant morbidity and mortality
  • Consider in patients with persistent dyspnea after PE 3, 6
• Post-PE syndrome:
  • Persistent dyspnea and exercise limitation
  • Affects up to 47% of patients at 1-year follow-up 3

Follow-Up Recommendations

• Routine clinical evaluation 3-6 months after acute PE episode
• Further diagnostic evaluation for patients with:
  • Persistent or new-onset dyspnea
  • Exercise limitation
  • Risk factors for CTEPH 3

Clinical Pitfalls to Avoid

• Misdiagnosis: PE symptoms can mimic other cardiopulmonary conditions
• Overlooking PE in patients with normal oxygen saturation
• Failing to consider PE in patients with pre-existing cardiopulmonary disease
• Delaying treatment: Prompt anticoagulation is essential to reduce mortality
• Inadequate follow-up: Monitor for recurrence and long-term complications 3, 1