What is the management of pulmonary embolism?

Management of Pulmonary Embolism

All patients with confirmed PE require immediate risk stratification based on hemodynamic stability, followed by anticoagulation with NOACs preferred over warfarin in eligible patients, systemic thrombolysis for high-risk PE, and at least 3 months of therapeutic anticoagulation. 1

Initial Risk Stratification

• Immediately assess for hemodynamic instability (shock, hypotension with systolic BP <90 mmHg) to identify high-risk PE patients with early mortality risk 1
• Patients without hemodynamic instability should be further stratified into intermediate-risk and low-risk categories based on clinical parameters 1
• In hemodynamically unstable patients when CT is unavailable, perform bedside echocardiography to assess for right ventricular overload 2

Acute Phase Management Algorithm

High-Risk PE (Hemodynamically Unstable)

• Administer systemic thrombolytic therapy immediately as the primary treatment for high-risk PE 1, 3
• Initiate unfractionated heparin (UFH) without delay while arranging thrombolysis 3
• Provide supplemental oxygen to correct hypoxemia (target SaO2 >90%) 4
• Use vasopressors (dobutamine and/or norepinephrine) to correct systemic hypotension and prevent right ventricular failure progression 3, 4
• Avoid aggressive fluid challenges as this worsens right ventricular dysfunction 4
• Perform surgical pulmonary embolectomy if thrombolysis is contraindicated or has failed 1, 3

Intermediate-Risk and Low-Risk PE (Hemodynamically Stable)

• Prefer LMWH or fondaparinux over UFH for initial parenteral anticoagulation 1
• Do not routinely administer systemic thrombolysis as primary treatment 1
• Consider rescue thrombolytic therapy only if hemodynamic deterioration occurs despite anticoagulation 1, 3

Oral Anticoagulation Selection

When initiating oral anticoagulation in PE patients eligible for NOACs, prefer a NOAC (apixaban, dabigatran, edoxaban, or rivaroxaban) over warfarin. 1

NOAC Therapy

• Rivaroxaban is FDA-approved for PE treatment and can be initiated without parenteral bridging 5
• Apixaban is FDA-approved for PE treatment 6
• Critical contraindications to NOACs: severe renal impairment (CrCl <15 mL/min for rivaroxaban) and antiphospholipid antibody syndrome 1, 5

Warfarin Alternative

• If using a vitamin K antagonist (VKA), overlap with parenteral anticoagulation until INR reaches 2.5 (range 2.0-3.0) 1
• Continue VKA indefinitely in patients with antiphospholipid antibody syndrome 1

Duration of Anticoagulation

• All patients require therapeutic anticoagulation for at least 3 months 1
• Discontinue after 3 months in patients with first PE secondary to a major transient/reversible risk factor 1
• Continue indefinitely in patients with recurrent VTE (at least one previous PE or DVT episode) not related to a major transient/reversible risk factor 1
• For extended anticoagulation, reassess drug tolerance, adherence, hepatic/renal function, and bleeding risk at regular intervals 1

Special Populations

Pregnancy and Postpartum

• Use therapeutic fixed doses of LMWH based on early pregnancy weight in pregnant women without hemodynamic instability 1
• Never use NOACs during pregnancy or lactation 1
• 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

Renal Impairment

• Avoid rivaroxaban in patients with CrCl <15 mL/min 5
• Calculate CrCl based on actual body weight when determining NOAC dosing 5

Management of Hypoxemia

• Escalate oxygen delivery sequentially: conventional oxygen → high-flow nasal cannula → non-invasive ventilation → invasive mechanical ventilation 4
• Reserve invasive mechanical ventilation for extreme instability, as positive pressure ventilation may worsen right ventricular failure 4
• If intubation is necessary, use lung-protective ventilation (tidal volumes ~6 mL/kg, plateau pressure <30 cm H2O, cautious PEEP) 4
• Consider right-to-left shunting through patent foramen ovale as a cause of refractory hypoxemia 4

Post-PE Follow-Up

• Routinely re-evaluate all patients 3-6 months after acute PE 1, 3
• Implement integrated care models to ensure optimal transition from hospital to ambulatory care 1, 3
• Refer symptomatic patients with mismatched perfusion defects on V/Q scan beyond 3 months to a pulmonary hypertension/CTEPH expert center 1, 3

Critical Pitfalls to Avoid

• Do not routinely use inferior vena cava filters 1
• Do not delay anticoagulation while awaiting diagnostic imaging in high-probability cases 2
• Do not use NOACs in severe renal impairment or antiphospholipid antibody syndrome 1
• Avoid premature discontinuation of anticoagulation without considering alternative coverage, as this increases thrombotic event risk 5
• Do not perform neuraxial procedures without careful timing considerations in anticoagulated patients due to spinal/epidural hematoma risk 5