What is the management approach for pulmonary embolism?

Management of Pulmonary Embolism

Direct oral anticoagulants (DOACs) are the first-line treatment for most patients with low to intermediate-risk pulmonary embolism (PE), with anticoagulation duration of at least 3 months and extended treatment for unprovoked PE or persistent risk factors. 1

Initial Assessment and Risk Stratification

• Assess clinical probability of PE based on:

  • Sudden collapse with raised jugular venous pressure
  • Pulmonary hemorrhage syndrome (pleuritic pain/hemoptysis)
  • Isolated dyspnea without cough/sputum/chest pain 2
  • Major risk factors (recent immobility, surgery, trauma, pregnancy, medical illness, previous VTE) 2

• Classify severity:

  • Massive/high-risk PE: Hypotension, shock, or cardiac arrest
  • Submassive/intermediate-risk PE: Normotensive with right ventricular dysfunction
  • Low-risk PE: Normotensive without right ventricular dysfunction

Diagnostic Workup

• D-dimer testing:

  • Only useful when negative and clinical probability is low/intermediate
  • Not recommended when alternative diagnosis is likely, clinical probability is high, or in suspected massive PE 2

• Imaging:

  • CT pulmonary angiography (CTPA) is the gold standard
  • Echocardiography is the most useful initial test in unstable patients 1
  • V/Q scan is an alternative when CTPA is contraindicated
  • Leg ultrasound is an alternative in those with clinical DVT 2

Treatment Algorithm

1. Massive PE (Hemodynamically unstable)

• Resuscitation if cardiac arrest
• Immediate anticoagulation with unfractionated heparin (UFH) 80 units/kg IV bolus
• Thrombolysis with alteplase:
  • 50 mg IV bolus if cardiac arrest is imminent
  • 100 mg over 90 minutes in stable patients with confirmed massive PE 2, 1
  • Contraindications to thrombolysis should be ignored in life-threatening PE 1

2. Submassive and Low-risk PE

• Anticoagulation:
  • Start immediately in patients with intermediate or high clinical probability, even before imaging confirmation 1
  • DOACs are first-line treatment:
    • Apixaban: 10 mg twice daily for 7 days, then 5 mg twice daily 1, 3
    • Rivaroxaban: 15 mg twice daily for 21 days, then 20 mg once daily 1, 4
  • If DOACs contraindicated, use LMWH or fondaparinux followed by warfarin (target INR 2.0-3.0) 1

3. Special Populations

• Pregnancy: LMWH is treatment of choice (DOACs contraindicated) 1
• Active cancer: LMWH for at least 6 months, then continuous anticoagulation while cancer is active 1
• Antiphospholipid syndrome: Vitamin K antagonists (not DOACs) indefinitely 1
• Renal impairment (CrCl <30 mL/min): Adjust LMWH dose 1

Duration of Anticoagulation

• Provoked PE (transient/reversible risk factors): 3 months 1
• Unprovoked PE or persistent risk factors: Extended treatment (>3 months) 1
• Recurrent PE: Indefinite anticoagulation 1

Vena Cava Filters

• Only indicated when:
  • Anticoagulation is contraindicated in high-risk patients
  • Recurrent PE despite adequate anticoagulation 2, 1
• Associated with increased risk of recurrent DVT (21% vs 12% at 2 years) 1
• If filter is placed, anticoagulation should be resumed once contraindications resolve 1
• Consider filter retrieval when no longer needed to reduce long-term complications 1

Outpatient Management

• Consider for patients who:
  • Are hemodynamically stable
  • Have no need for thrombolysis
  • Have oxygen saturation >90% on room air
  • Don't require IV analgesia
  • Have no high bleeding risk
  • Have adequate social support and follow-up 1

Follow-up

• Clinical follow-up at 3-6 months to assess:
  • Medication adherence
  • Bleeding complications
  • Signs of chronic thromboembolic pulmonary hypertension (CTEPH)
  • Need for extended anticoagulation 1
• Consider compression stockings within 1 month of DVT diagnosis and continue for at least 1 year to prevent post-thrombotic syndrome 1

Common Pitfalls

• Delaying anticoagulation while awaiting confirmatory testing in high-risk patients
• Inappropriate use of D-dimer as a screening test in high-probability cases
• Failure to consider thrombolysis in massive PE
• Premature discontinuation of anticoagulation in unprovoked PE
• Overuse of IVC filters when anticoagulation is possible

The management of PE has evolved significantly with the introduction of DOACs, which have simplified treatment while maintaining efficacy. Risk stratification is crucial to determine the appropriate treatment intensity and setting, while the duration of anticoagulation should be tailored based on whether the PE was provoked or unprovoked.