What is the treatment for pulmonary embolism?

Treatment for Pulmonary Embolism

The treatment for pulmonary embolism consists primarily of anticoagulation with low molecular weight heparin (LMWH) as initial therapy, followed by transition to direct oral anticoagulants (DOACs) like rivaroxaban or apixaban for most patients, with thrombolysis reserved for hemodynamically unstable patients with massive PE. 1

Initial Anticoagulation

Standard Approach (Hemodynamically Stable PE)

• LMWH is preferred over unfractionated heparin (UFH) for initial parenteral anticoagulation in hemodynamically stable patients 1
• Administer LMWH according to weight-based dosing
• Monitor for bleeding complications and heparin-induced thrombocytopenia
• No routine aPTT monitoring needed with LMWH (advantage over UFH)

Massive PE (Hemodynamically Unstable)

• UFH is preferred for patients with massive PE requiring possible thrombolysis 1
  • Initial IV bolus: 80 U/kg
  • Continuous infusion: 18 U/kg/hour
  • Target aPTT: 1.5-2.5 times control value
• Monitor aPTT at 4-6 hours after starting treatment, 6-10 hours after dose changes, and daily thereafter 2, 1
• UFH preferred due to its shorter half-life and reversibility with protamine sulfate if bleeding complications occur 1

Thrombolysis

Indications

• First-line treatment for high-risk PE with hemodynamic instability 1
• Consider in patients with:
  • Hypotension
  • Shock
  • Right ventricular dysfunction with clinical deterioration

Approved Regimens

• Alteplase (rtPA): 100 mg over 2 hours or 0.6 mg/kg over 15 minutes (maximum 50 mg) 2, 1
• Streptokinase: 250,000 IU loading dose over 30 minutes, then 100,000 IU/hour for up to 24 hours 2
• Urokinase: Available in some regions

Contraindications to Thrombolysis

• Hemorrhagic stroke (any time)
• Ischemic stroke within 6 months
• Central nervous system damage or neoplasms
• Recent major trauma/surgery/head injury (within 3 weeks)
• Gastrointestinal bleeding within the last month
• Known active bleeding 1

Transition to Long-Term Anticoagulation

Direct Oral Anticoagulants (DOACs)

• Preferred over vitamin K antagonists (warfarin) for most patients 1
• Options include:
  • Rivaroxaban: FDA-approved for PE treatment 3
  • Apixaban: FDA-approved for PE treatment 4
  • Dabigatran and edoxaban (after initial parenteral anticoagulation)

Vitamin K Antagonists (Warfarin)

• Alternative when DOACs are contraindicated
• Overlap with parenteral anticoagulation until INR of 2.0-3.0 is reached for at least 2 consecutive days 1
• Target INR: 2.0-3.0

Duration of Anticoagulation

• First episode with major transient/reversible risk factor: 3 months 1
• Unprovoked PE or ongoing risk factors: Extended anticoagulation (>3 months) 1
• Recurrent VTE: Indefinite anticoagulation 1

Special Populations

Cancer Patients

• LMWH preferred over VKA or DOACs for at least 6 months 1
• Continue treatment as long as cancer is active

Pregnant Patients

• LMWH is the treatment of choice 1
• Avoid warfarin and DOACs due to teratogenicity and placental transfer

Additional Interventions

IVC Filter

• Consider if absolute contraindication to anticoagulation exists
• Consider for recurrent PE despite therapeutic anticoagulation 1
• Retrievable filters preferred when possible

Follow-up and Monitoring

• Re-evaluate patients 3-6 months after acute PE 1
• Assess for:
  • Signs of post-thrombotic syndrome
  • Chronic thromboembolic pulmonary hypertension
  • Drug tolerance and adherence
  • Renal/hepatic function
  • Bleeding risk

Common Pitfalls to Avoid

1. Delaying anticoagulation while awaiting diagnostic confirmation in patients with intermediate/high clinical probability of PE
2. Underdosing LMWH in obese patients (use actual body weight for dosing)
3. Failing to consider thrombolysis in rapidly deteriorating patients with massive PE
4. Not monitoring platelet counts for heparin-induced thrombocytopenia
5. Inappropriate IVC filter placement without clear indication
6. Premature discontinuation of anticoagulation (increases risk of recurrent thrombotic events) 3