What is the initial management and workup for a patient suspected of having Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE)?

Initial Management and Workup for Suspected DVT/PE

Immediate Clinical Assessment and Risk Stratification

For patients with suspected DVT or PE, initiate anticoagulation immediately while awaiting diagnostic confirmation if clinical suspicion is high, and proceed with same-day imaging whenever reasonably practical. 1

Clinical Prediction Rules and Initial Triage

• Apply Wells' Criteria or Revised Geneva Score to stratify pretest probability before ordering diagnostic tests 1, 2
• For high clinical suspicion of PE, start parenteral anticoagulation immediately while awaiting diagnostic test results 1
• For intermediate clinical suspicion of PE, initiate parenteral anticoagulation if diagnostic results will be delayed more than 4 hours 1
• For low clinical suspicion of PE, anticoagulation can be withheld if test results are expected within 24 hours 1
• For suspected DVT with high clinical suspicion, treat with anticoagulants while awaiting imaging results 3

Hemodynamic Assessment for PE

• Immediately assess for signs of massive PE: systolic blood pressure <90 mm Hg, heart rate >110 bpm, oxygen saturation <90% on room air, or requirement for inotropes 1, 4
• Check for engorged neck veins and right ventricular gallop as additional indicators of hemodynamic compromise 4
• Hemodynamically unstable patients require immediate thrombolysis consideration and should not be delayed for additional imaging 4

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Initial Diagnostic Workup

Laboratory Testing

• Obtain complete blood count with platelet count, PT, aPTT, liver and kidney function tests as part of initial workup 1, 5
• Measure N-terminal pro-BNP and troponin for PE cases to assess right ventricular strain 1
• D-dimer testing should be used only in low-risk DVT patients or moderate-risk PE patients to rule out disease 2
• Do not rely on D-dimer in high clinical probability cases or probable massive PE 4

Imaging for DVT

• Venous compression ultrasonography is the preferred initial imaging modality for suspected DVT 5, 6
• If initial ultrasound is negative but clinical suspicion remains high, repeat venous ultrasound within 5-7 days or proceed to CT venogram or MR venogram 5
• Do not repeat ultrasound routinely—only when symptoms persist or worsen despite previous negative results 5

Imaging for PE

• CT pulmonary angiography (CTA) is the preferred diagnostic test for suspected PE 1, 2
• Ventilation-perfusion (VQ) scan is the alternative when CTA is contraindicated (renal insufficiency, contrast allergy, pregnancy) 1
• Chest x-ray may be omitted if CTA is planned 1
• Do not delay transfer of unstable patients for additional imaging studies 4

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Initial Anticoagulation Management

Parenteral Anticoagulation for PE

• Initiate parenteral anticoagulation immediately with LMWH, fondaparinux, IV UFH, or SC UFH for confirmed PE 1
• LMWH or fondaparinux is preferred over IV UFH for most patients with acute PE 1
• IV UFH is preferred when concern exists about subcutaneous absorption adequacy or when thrombolytic therapy is being considered 1

Direct Oral Anticoagulants (DOACs) as First-Line

• Apixaban or rivaroxaban can be initiated immediately without parenteral bridging for both DVT and PE 1, 7, 8, 2
• Apixaban dosing: 10 mg twice daily for 7 days, then 5 mg twice daily 7
• Rivaroxaban dosing: 15 mg twice daily for 3 weeks, then 20 mg once daily 8
• Edoxaban or dabigatran require initial LMWH bridging for at least 5 days before starting 1

Vitamin K Antagonist (VKA) Approach

• If using warfarin, start on the same day as parenteral anticoagulation at the estimated patient-specific daily dose without loading 1, 9
• Continue parenteral anticoagulation for minimum 5 days and until INR is 2.0 or above for at least 24 hours 1
• Target INR range is 2.0-3.0 for all VTE treatment 1, 3

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Outpatient vs Inpatient Management

Criteria for Outpatient DVT Management

• Most patients with acute uncomplicated DVT can be treated as outpatients 2
• Outpatient management is appropriate when home circumstances are adequate and patient meets low-risk criteria 1

Criteria for Outpatient PE Management

• Use PESI (Pulmonary Embolism Severity Index) or sPESI to identify low-risk patients eligible for outpatient care 1
• Apply exclusion criteria before outpatient management: hemodynamic instability, oxygen saturation <90%, active bleeding risk, severe pain requiring opiates, severe kidney disease (eGFR <30 mL/min), inadequate home support 1
• RV dilatation on imaging with elevated cardiac biomarkers should prompt inpatient admission for observation 1

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Special Considerations

Thrombolysis Indications

• Systemic thrombolysis is recommended for massive PE with hemodynamic instability 1, 4
• For most patients with nonmassive PE, do not use systemic thrombolytic therapy 3
• In life-threatening PE, contraindications to thrombolysis should be ignored 4
• Catheter-directed thrombolysis may be considered in centers with appropriate expertise, especially for patients at intermediate-to-high bleeding risk 1

IVC Filter Placement

• IVC filters are not recommended when anticoagulation is possible 1
• Consider retrievable IVC filter only when absolute contraindication to anticoagulation exists, with retrieval as soon as anticoagulation becomes feasible 1

Cancer Patients

• Cancer patients should receive LMWH over warfarin for long-term DVT/PE treatment 5
• More frequent clinical assessment is needed due to higher recurrence and bleeding risk 5

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Common Pitfalls to Avoid

• Do not withhold anticoagulation in high-risk patients while awaiting imaging—treat empirically 1
• Do not use compression stockings routinely—evidence shows they do not reduce post-thrombotic syndrome 1
• Do not perform routine thrombophilia testing—it does not change acute management 6
• Do not miss bilateral edema from other causes by focusing solely on DVT 5
• Do not use high-intensity warfarin (INR 3.1-4.0) or low-intensity warfarin (INR 1.5-1.9)—both are inferior to standard INR 2.0-3.0 1, 3