Treatment of Pulmonary Embolism
Immediate Risk Stratification Determines Treatment Intensity
Treatment of pulmonary embolism must be immediately stratified by hemodynamic status: high-risk PE (shock/hypotension) requires systemic thrombolysis plus anticoagulation; intermediate-risk PE (stable with RV dysfunction) receives anticoagulation alone with rescue thrombolysis if deterioration occurs; and low-risk PE (stable without RV dysfunction) is treated with anticoagulation preferably using NOACs over warfarin. 1, 2
High-Risk PE: Aggressive Reperfusion Required
High-risk PE is defined by the presence of shock or persistent hypotension and carries the highest mortality risk. 1, 2
Immediate Management Protocol
Initiate unfractionated heparin (UFH) immediately with a weight-adjusted bolus of 80 U/kg (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. 1, 3, 4
Administer systemic thrombolytic therapy immediately unless absolute contraindications exist—this is the first-line treatment for high-risk PE. 1, 2
Provide supplemental oxygen to correct hypoxemia. 3
Use vasopressors (norepinephrine and/or dobutamine) to correct hypotension and support hemodynamics. 1, 3
When Thrombolysis Fails or Is Contraindicated
Surgical pulmonary embolectomy is recommended via median sternotomy with cardiopulmonary bypass when thrombolysis is contraindicated or has failed. 1, 5
Percutaneous catheter-directed treatment should be considered as an alternative to surgery. 1, 2
ECMO may be considered in combination with surgical embolectomy or catheter-directed treatment in patients with refractory circulatory collapse or cardiac arrest. 1
Intermediate-Risk and Low-Risk PE: Anticoagulation Strategy
For hemodynamically stable patients (intermediate- or low-risk), anticoagulation is the cornerstone of treatment. 1
Initiation of Anticoagulation
Begin anticoagulation immediately without delay, even while diagnostic workup is in progress if clinical probability is high or intermediate. 1
For parenteral anticoagulation, prefer LMWH or fondaparinux over UFH in most patients without hemodynamic instability. 1, 6, 7
UFH is reserved for specific situations: severe renal impairment, high bleeding risk, hemodynamic instability, or morbid obesity. 3, 6
Transition to Oral Anticoagulation
When initiating oral anticoagulation, prefer a NOAC (apixaban, dabigatran, edoxaban, or rivaroxaban) over vitamin K antagonists (VKAs). 1, 2
Specific NOAC dosing: Rivaroxaban 15 mg PO twice daily with food for 21 days, then 20 mg once daily; or apixaban 10 mg PO twice daily for 7 days, then 5 mg twice daily. 5
If using VKA (warfarin), overlap with parenteral anticoagulation until INR reaches 2.5 (range 2.0-3.0) for 24 hours. 1, 5
NOAC Contraindications
NOACs are contraindicated in: severe renal impairment, pregnancy and lactation, and antiphospholipid antibody syndrome—use VKA or LMWH instead. 1, 3
Rescue Therapy for Deterioration
Administer rescue thrombolytic therapy if hemodynamic deterioration occurs despite anticoagulation. 1
Surgical embolectomy or catheter-directed treatment should be considered as alternatives to rescue thrombolysis. 1
Duration of Anticoagulation
Discontinue after 3 months for first PE secondary to a major transient/reversible risk factor (provoked PE). 1, 2
Continue indefinitely for recurrent VTE (at least one previous episode) not related to a major transient or reversible risk factor (unprovoked PE). 1, 2
Cancer-associated PE requires LMWH for at least 6 months, then continue as long as cancer is active. 2
Antiphospholipid antibody syndrome requires indefinite VKA therapy. 1
Special Populations
Pregnancy
Fixed-dose LMWH based on early pregnancy weight is the treatment of choice. 1, 5
Do not insert spinal/epidural needle within 24 hours of last LMWH dose. 1
Do not administer LMWH within 4 hours of epidural catheter removal. 1
NOACs are absolutely contraindicated during pregnancy and lactation. 1, 3
Inferior Vena Cava Filters
IVC filters should be considered only in patients with absolute contraindications to anticoagulation or PE recurrence despite therapeutic anticoagulation. 1, 5
Routine use of IVC filters is not recommended. 1
Early Discharge and Outpatient Management
- Carefully selected low-risk PE patients should be considered for early discharge and home treatment if proper outpatient care and anticoagulant treatment can be provided. 1, 3
Post-PE Follow-Up
Routinely reassess patients at 3-6 months post-PE to evaluate for persistent dyspnea, functional limitation, or chronic thromboembolic pulmonary hypertension (CTEPH). 1, 2, 5
Refer symptomatic patients with mismatched perfusion defects on V/Q scan beyond 3 months to a pulmonary hypertension/CTEPH expert center. 1, 5
Implement an integrated care model to ensure optimal transition from hospital to ambulatory care. 1, 5
Critical Pitfalls to Avoid
Do not measure D-dimers in high clinical probability patients—a normal result does not safely exclude PE. 1
Do not routinely use systemic thrombolysis in intermediate- or low-risk PE. 1
Do not confuse heparin vial strengths—ensure the correct concentration is selected to avoid fatal dosing errors. 4
Avoid intramuscular injections due to frequent hematoma formation. 4