What is the approach to managing a patient with pulmonary embolism?

Approach to Pulmonary Embolism

Immediate Actions Upon Suspicion

Start anticoagulation immediately when PE is suspected based on clinical probability, even before diagnostic confirmation, unless active bleeding or absolute contraindications exist. 1

• Administer weight-adjusted IV heparin with an initial bolus of 80 IU/kg, followed by continuous infusion of 18 IU/kg/hour, targeting aPTT 1.5-2.5 times control (45-75 seconds). 1, 2
• Check first aPTT 4-6 hours after initial bolus, then daily once therapeutic. 2
• Perform bedside transthoracic echocardiography immediately in hemodynamically unstable patients to differentiate high-risk PE from other acute life-threatening conditions. 1

Risk Stratification

High-risk PE is defined by systemic hypotension (systolic BP <90 mmHg), cardiogenic shock, or sudden collapse with elevated jugular venous pressure. 1, 2

• Most PE patients present with breathlessness and/or tachypnea (respiratory rate >20/min). 1, 2
• PE is rare in patients under age 40 without risk factors. 2
• High-risk populations include elderly patients, those with severe pre-existing cardiorespiratory disease, and patients with isolated dyspnea. 2

Diagnostic Algorithm

• Normal D-dimer excludes PE in patients with low to intermediate clinical probability. 1
• Proceed to CT pulmonary angiography (CTPA) for patients with high clinical probability or elevated D-dimer. 1
• If CTPA shows single subsegmental PE, consider false-positive findings and obtain radiology second opinion before committing to anticoagulation. 1
• D-dimer testing is useless in hemodynamically unstable patients; rely on clinical probability and bedside echocardiography instead. 3

Treatment Based on Risk Category

High-Risk (Hemodynamically Unstable) PE

Systemic thrombolysis is indicated for patients with systemic hypotension or cardiogenic shock. 1, 2

• Thrombolytic regimens include rtPA, streptokinase, or urokinase. 2
• Consider surgical embolectomy if thrombolysis is contraindicated or fails to produce clinical improvement within one hour. 1
• Supportive care includes oxygen, fluid loading, and inotropes. 3
• Avoid transferring unstable patients to radiology; use bedside diagnostics. 3

Hemodynamically Stable PE

Prefer novel oral anticoagulants (NOACs) over traditional LMWH-warfarin regimen unless contraindications exist. 1

• Continue heparin for 7-10 days, overlapping with oral anticoagulants during the last 4-5 days. 1, 2
• Rivaroxaban (XARELTO) is FDA-approved for PE treatment and can be used as monotherapy without initial heparin bridging in stable patients. 4

Special Population Considerations

Cancer-Associated PE

Low molecular weight heparin (LMWH) is superior to NOACs and should be continued indefinitely while cancer is active. 1

Antiphospholipid Syndrome

• Test for antiphospholipid antibodies in unprovoked or recurrent PE. 1
• NOACs are contraindicated in triple-positive APS; use warfarin (INR 2.0-3.0) instead. 1, 5

Renal Impairment

• Rivaroxaban can be used with CrCl ≥15 mL/min for PE treatment, though patients with CrCl <30 mL/min were not studied. 4
• Avoid rivaroxaban when CrCl <15 mL/min. 4

Duration of Anticoagulation

Minimum 3 months anticoagulation for all confirmed PE. 1, 2

• Discontinue after 3 months: First episode with strong transient/reversible risk factor (e.g., recent surgery, immobilization). 1, 2
• Continue indefinitely: Unprovoked PE, recurrent VTE, or active cancer. 1, 2
• Re-examine patient after initial 3-6 months to weigh benefits versus bleeding risks for extended anticoagulation. 1

IVC Filter Placement

Place IVC filter only in patients with absolute contraindication to anticoagulation or recurrent PE despite adequate anticoagulation. 1

Follow-Up Protocol

• Initial follow-up within 1-2 weeks of discharge. 1, 5
• Comprehensive assessment at 6-12 weeks. 1, 5
• Yearly examinations for patients on extended anticoagulation. 1
• Ask about persistent or new-onset dyspnea or functional limitation at every visit. 1
• If symptomatic after 3 months, implement staged diagnostic workup to exclude chronic thromboembolic pulmonary hypertension (CTEPH). 1, 5

Critical Safety Warnings

Premature Discontinuation

Premature discontinuation of any oral anticoagulant increases the risk of thrombotic events; consider coverage with another anticoagulant if stopping for reasons other than bleeding or treatment completion. 4

Neuraxial Procedures

• Epidural or spinal hematomas can occur with rivaroxaban during neuraxial anesthesia or spinal puncture, potentially causing permanent paralysis. 4
• Risk factors include indwelling epidural catheters, concomitant NSAIDs or antiplatelet agents, history of spinal trauma/surgery, and spinal deformity. 4
• Monitor frequently for neurological impairment; urgent treatment is necessary if compromise occurs. 4

Patient Education on Anticoagulation

• Patients on warfarin must maintain INR 2.0-3.0 with regular monitoring. 5
• Patients on DOACs should take medication exactly as prescribed and review potential drug interactions. 5
• Seek immediate care for worsening dyspnea, chest pain, hemoptysis, dizziness/syncope, or bleeding complications. 5
• Avoid high-risk trauma activities and inform all healthcare providers about anticoagulant use. 5