What is the treatment for pulmonary embolism?

Treatment of Pulmonary Embolism

For patients with pulmonary embolism who are eligible for oral anticoagulation, a non-vitamin K antagonist oral anticoagulant (NOAC) such as apixaban, rivaroxaban, edoxaban, or dabigatran is the recommended first-line anticoagulant treatment. 1

Risk Stratification Determines Treatment Intensity

Treatment must be immediately tailored based on hemodynamic status, which directly impacts mortality risk:

High-Risk PE (Hemodynamically Unstable with Shock or Hypotension)

Immediate systemic thrombolytic therapy is the standard of care and should be administered without delay unless contraindicated. 1, 2

• Start unfractionated heparin (UFH) immediately with an 80 U/kg bolus (or 5,000-10,000 units) followed by continuous infusion at 18 U/kg/h, adjusted to maintain aPTT 1.5-2.5 times control 3, 2
• Provide supplemental oxygen to correct hypoxemia (target SaO2 >90%) 4, 3
• Use vasopressors (norepinephrine and/or dobutamine) to correct hypotension and prevent right ventricular failure progression 1, 3, 2
• Avoid aggressive fluid challenges as this worsens right ventricular dysfunction 4, 2
• If thrombolysis is contraindicated or fails, surgical pulmonary embolectomy or catheter-directed treatment should be considered as alternatives (upgraded from Class IIb to IIa in 2019) 1, 2
• ECMO may be considered in combination with surgical embolectomy or catheter-directed treatment for refractory circulatory collapse or cardiac arrest 1

Intermediate-Risk PE (Hemodynamically Stable with Right Ventricular Dysfunction)

• Initiate low molecular weight heparin (LMWH) or fondaparinux over UFH for initial parenteral anticoagulation 3, 2
• Do not routinely administer systemic thrombolysis as primary treatment 2
• Rescue thrombolytic therapy is now recommended (Class I) if the patient deteriorates hemodynamically despite anticoagulation (upgraded from Class IIa in 2014) 1, 2
• Multidisciplinary team management should be considered for selected intermediate-risk cases 1
• Assessment of right ventricular function by imaging or laboratory biomarkers should be performed even in patients with low PESI scores 1

Low-Risk PE (Hemodynamically Stable without Right Ventricular Dysfunction)

• Use LMWH or fondaparinux for initial parenteral anticoagulation 3, 2
• Early discharge and home treatment should be considered for carefully selected patients with proper outpatient care arrangements 3, 2

Transition to Oral Anticoagulation

When initiating oral anticoagulation, NOACs (apixaban, dabigatran, edoxaban, or rivaroxaban) are the recommended form of treatment over vitamin K antagonists (VKAs). 1, 2

• Apixaban and rivaroxaban are FDA-approved for treatment of PE 5, 6
• After the first 6 months, a reduced dose of apixaban or rivaroxaban should be considered for extended therapy 1

Duration of Anticoagulation

• All patients require therapeutic anticoagulation for at least 3 months 2
• Discontinue after 3 months if first PE was secondary to a major transient/reversible risk factor 2
• Extended anticoagulation should be considered for patients with:
  • No identifiable risk factor for the index PE event 1
  • Persistent risk factors other than antiphospholipid antibody syndrome 1
  • Minor transient/reversible risk factors 1
• Indefinite treatment with a VKA is required for patients with antiphospholipid antibody syndrome 1

Special Populations

Cancer-Associated PE

• Edoxaban or rivaroxaban should be considered as alternatives to LMWH, except in patients with gastrointestinal cancer 1

Pregnancy and Lactation

• Use therapeutic fixed doses of LMWH based on early pregnancy weight 2
• Thrombolysis or surgical embolectomy should be considered for pregnant women with high-risk PE 1
• NOACs are contraindicated during pregnancy or lactation 1, 3, 2

Severe Renal Impairment

• NOACs are contraindicated; use UFH instead 3, 2

Management of Hypoxemia

Escalate oxygen delivery sequentially based on response 4, 2:

1. Conventional supplemental oxygen for SaO2 <90% 4
2. High-flow oxygen via nasal cannula if conventional oxygen insufficient 4
3. Non-invasive ventilation if high-flow oxygen fails 4
4. Invasive mechanical ventilation only for extreme instability (positive pressure may worsen right ventricular failure) 4, 2

If intubation becomes necessary:

• Use tidal volumes of approximately 6 mL/kg lean body weight 4
• Keep end-inspiratory plateau pressure <30 cm H2O 4
• Apply positive end-expiratory pressure cautiously 4
• Avoid anesthetic drugs that cause hypotension 4

Post-PE Follow-Up

• Routine clinical evaluation is required 3-6 months after acute PE 1, 2
• An integrated model of care is recommended to ensure optimal transition from hospital to ambulatory care 1, 2
• Symptomatic patients with mismatched perfusion defects on V/Q scan >3 months after acute PE should be referred to a pulmonary hypertension/CTEPH expert center 1

Critical Pitfalls to Avoid

• Do not delay anticoagulation while awaiting diagnostic imaging in high-probability cases 2
• Do not use aggressive fluid challenges in PE patients with right ventricular dysfunction 4, 2
• Do not routinely use inferior vena cava filters; reserve only for absolute contraindications to anticoagulation or PE recurrence despite therapeutic anticoagulation 3, 2
• Do not overlook right-to-left shunting through a patent foramen ovale as a cause of refractory hypoxemia 4
• Do not fail to consider rescue thrombolysis in patients with worsening hypoxemia and hemodynamic deterioration despite anticoagulation 4
• Do not use NOACs in severe renal impairment, pregnancy/lactation, or antiphospholipid antibody syndrome 1, 3, 2