What is the management of pulmonary embolism?

Management of Pulmonary Embolism

Immediate anticoagulation should be initiated in all patients with suspected PE while diagnostic workup proceeds, with treatment stratified by hemodynamic stability: high-risk PE requires systemic thrombolysis, intermediate-risk PE is managed with anticoagulation alone (with rescue thrombolysis if deterioration occurs), and low-risk PE is treated with anticoagulation preferably using NOACs over warfarin. 1

Risk Stratification

Risk stratification is the critical first step that determines the entire treatment pathway 1:

• High-risk PE: Presence of shock (systolic BP <90 mmHg or drop ≥40 mmHg for >15 minutes) or persistent hypotension 1
• Intermediate-risk PE: Hemodynamically stable but with evidence of right ventricular dysfunction on echocardiography or CT, and/or elevated cardiac biomarkers (troponin, BNP/NT-proBNP) 1
• Low-risk PE: Hemodynamically stable without right ventricular dysfunction or myocardial injury 1

High-Risk (Massive) PE Management

Immediate Resuscitation

For patients with high-risk PE presenting with shock or cardiac arrest 2:

• Cardiac arrest: Administer 50 mg alteplase IV bolus immediately during CPR 2, 1
• Hemodynamically unstable but not arrested: Give unfractionated heparin 80 U/kg IV bolus (or 5,000-10,000 units) followed by 18 U/kg/h continuous infusion 2, 3
• Provide oxygen to correct hypoxemia 2, 3
• Use vasopressors (norepinephrine and/or dobutamine) to maintain systemic blood pressure and prevent right ventricular failure progression 3

Systemic Thrombolysis

Thrombolytic therapy is the first-line treatment for high-risk PE unless absolutely contraindicated 1:

• Stable high-risk patients: Alteplase 100 mg IV over 90 minutes (accelerated MI regimen) 2, 1
• Follow thrombolysis with unfractionated heparin after 3 hours, preferably weight-adjusted 2
• Critical caveat: In life-threatening PE, contraindications to thrombolysis should be ignored 2

Surgical and Catheter-Based Interventions

When thrombolysis is contraindicated or has failed 1:

• Surgical pulmonary embolectomy is recommended via median sternotomy with normothermic cardiopulmonary bypass 2
• Optimal surgical candidates have subtotal obstruction of main pulmonary artery or major branches without fixed pulmonary hypertension 2
• Operative mortality ranges 20-50%, but long-term survival is acceptable (71% at 8 years) 2
• Consider IVC filter insertion at time of surgery, though this remains controversial if no DVT is present and anticoagulation is not contraindicated 2
• Percutaneous catheter embolectomy may be considered in select patients not requiring CPR 2

Intermediate-Risk PE Management

Routine primary thrombolysis is NOT recommended for intermediate-risk PE 1:

• Initiate anticoagulation immediately with LMWH or fondaparinux (preferred over UFH) 1, 3
• Rescue thrombolytic therapy is recommended if hemodynamic deterioration occurs on anticoagulation 1
• Close monitoring is essential to detect early signs of decompensation 1

Low-Risk PE Management

Initial Anticoagulation

Anticoagulation should be initiated without delay 1:

• Preferred initial therapy: LMWH or fondaparinux over unfractionated heparin 1, 3
• UFH is reserved for patients with severe renal impairment (CrCl <30 mL/min) or high bleeding risk requiring rapid reversibility 3

Long-Term Anticoagulation

NOACs are recommended over vitamin K antagonists for most patients 1:

• Rivaroxaban: 15 mg PO twice daily with food for 21 days, then 20 mg once daily with food 4
• Apixaban: 10 mg PO twice daily for 7 days, then 5 mg twice daily 5
• Warfarin alternative: Target INR 2.5 (range 2.0-3.0) if NOACs contraindicated 2, 3

NOAC Contraindications

NOACs should NOT be used in 2, 3:

• Severe renal impairment (CrCl <15-30 mL/min depending on agent)
• Pregnancy and lactation
• Antiphospholipid antibody syndrome (use warfarin indefinitely) 2

Early Discharge Considerations

Carefully selected low-risk PE patients may be considered for early discharge and home treatment 1:

• Patient must not be unduly breathless 2
• No medical or social contraindications present 2
• Efficient outpatient protocol in place 2

Duration of Anticoagulation

Treatment duration depends on risk factor profile 2:

• Temporary/reversible risk factors: 4-6 weeks minimum 2
• First idiopathic PE: 3 months 2
• Recurrent VTE or persistent risk factors: At least 6 months, consider extended therapy 2, 1
• Extended anticoagulation: Reassess drug tolerance, adherence, hepatic/renal function, and bleeding risk at regular intervals 2

Special Considerations

Pregnancy

Fixed-dose LMWH based on early pregnancy weight is the treatment of choice 2:

• Do not insert spinal/epidural needle within 24 hours of last LMWH dose 2
• Do not administer LMWH within 4 hours of epidural catheter removal 2
• NOACs are absolutely contraindicated during pregnancy and lactation 2

IVC Filters

Routine IVC filter use is NOT recommended 1:

• Consider only for: absolute contraindications to anticoagulation, or PE recurrence despite therapeutic anticoagulation 1, 3
• Retrievable filters may be removed after 10-14 days if venography shows no distal thrombi 2

Post-PE Follow-Up

Routine re-evaluation at 3-6 months after acute PE is essential 2, 1:

• Implement integrated care model to ensure optimal transition from hospital to ambulatory care 2
• Refer symptomatic patients with mismatched perfusion defects on V/Q scan beyond 3 months to a pulmonary hypertension/CTEPH expert center 2
• Consider echocardiography, natriuretic peptides, and/or cardiopulmonary exercise testing to guide referral 2

Common Pitfalls

• Never delay anticoagulation while awaiting diagnostic confirmation in patients with high clinical probability 1
• Do not use D-dimer in high clinical probability or probable massive PE 2
• Avoid premature discontinuation of anticoagulation, as this significantly increases thrombotic event risk 4
• Monitor closely for neuraxial hematoma in patients receiving spinal/epidural procedures while on anticoagulation 4
• Adjust heparin dosing using weight-based nomograms to maintain aPTT 1.5-2.5 times control 2, 3