What is the treatment for pulmonary embolism vs pulmonary infarct?

Treatment of Pulmonary Embolism vs Pulmonary Infarct

The treatment for pulmonary embolism (PE) and pulmonary infarct is fundamentally the same, with anticoagulation being the cornerstone therapy for both conditions, as pulmonary infarct is a complication of PE where tissue death occurs due to lack of blood supply. 1

Understanding the Relationship Between PE and Pulmonary Infarct

• Pulmonary infarct is a complication of PE that occurs when a blood clot causes tissue death in the lung parenchyma due to obstruction of blood flow 2
• Only about 10% of pulmonary emboli lead to pulmonary infarction, making it a less common complication 2
• Pulmonary infarct may occasionally lead to secondary spontaneous pneumothorax, which requires additional management with chest tube drainage 2

Initial Assessment and Risk Stratification

• Assess hemodynamic stability immediately to determine if the patient has massive PE (high-risk) or non-massive PE (intermediate/low-risk) 1
• Signs of massive PE include:
  • Collapse/hypotension
  • Unexplained hypoxia
  • Engorged neck veins
  • Right ventricular gallop (often present) 1
• Echocardiography is crucial for risk stratification, especially to identify right ventricular dysfunction 3, 4
• Clinical probability assessment should be performed using validated criteria:
  • Is another diagnosis unlikely? (chest radiograph and ECG are helpful)
  • Is there a major risk factor (immobility, surgery, trauma, pregnancy, etc.)? 1

Treatment Algorithm Based on Risk Stratification

1. High-Risk/Massive PE (with hemodynamic instability)

• Immediate resuscitation measures and oxygen supplementation 1
• Administer intravenous unfractionated heparin (UFH) bolus of 80 units/kg 1
• Thrombolysis is first-line treatment for massive PE 1:
  • Alteplase 50 mg IV bolus if cardiac arrest is imminent
  • For stable patients with confirmed massive PE: alteplase 100 mg over 90 minutes 1
• After thrombolysis, resume unfractionated heparin after 3 hours, preferably weight-adjusted 1
• Consider invasive approaches (thrombus fragmentation, IVC filter) where facilities and expertise are available 1

2. Intermediate-Risk/Non-Massive PE (hemodynamically stable but with RV dysfunction)

• Anticoagulation with either:
  • Low molecular weight heparin (LMWH) - preferred over UFH due to equal efficacy, safety, and easier use 1
  • Unfractionated heparin (UFH) - consider for patients who may need rapid reversal 1
  • Novel oral anticoagulants (NOACs) like rivaroxaban - preferred over traditional LMWH-VKA regimen unless contraindicated 1, 5
• Monitor closely for signs of deterioration; if deterioration occurs, consider rescue thrombolytic therapy 1
• Thrombolysis is not recommended as first-line treatment in non-massive PE 1

3. Low-Risk PE (hemodynamically stable without RV dysfunction)

• Anticoagulation with either LMWH or NOACs 1
• Consider outpatient treatment if:
  • Patient is not unduly breathless
  • No medical or social contraindications exist
  • An efficient protocol is in place (similar to outpatient DVT management) 1

4. Pulmonary Infarct (specific considerations)

• Same anticoagulation regimen as for PE 1
• Additional management for symptoms:
  • Analgesia for severe pleuritic pain (avoid opiates in patients with incipient cardiovascular collapse) 1
  • If secondary pneumothorax develops, place intercostal drain 2
• Monitor for complications such as cavitation or pneumothorax 2

Duration of Anticoagulation

• Standard duration of oral anticoagulation depends on risk factors 1:
  • 4-6 weeks for temporary risk factors
  • 3 months for first idiopathic event
  • At least 6 months for other cases
• For recurrent events, consider indefinite anticoagulation 1
• Target INR should be 2.0-3.0 for patients on warfarin 1
• When using NOACs like rivaroxaban, follow FDA-approved dosing regimens 5

Follow-up Considerations

• Re-examine the patient after the first 3-6 months of anticoagulation to weigh benefits vs. risks of continuing treatment 1
• Assess for persisting or new-onset dyspnea or functional limitation that might indicate chronic thromboembolic pulmonary hypertension (CTEPH) 1
• Consider testing for thrombophilia in patients under 50 with recurrent PE or those with a strong family history of VTE 1

Common Pitfalls to Avoid

• Do not delay anticoagulation while awaiting diagnostic confirmation in patients with intermediate or high clinical probability 1
• Do not use thrombolysis as first-line treatment in non-massive PE due to bleeding risk 1
• Do not ignore contraindications to thrombolysis except in life-threatening PE where no alternatives exist 1
• Do not routinely use inferior vena cava filters 1
• Do not use NOACs in patients with severe renal impairment or antiphospholipid antibody syndrome 1