Key Points
- Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
- Use system-specific risk tools to guide testing and disposition.
- Order high-yield tests first; escalate imaging when indicated.
- Start evidence-based initial therapy and reassess frequently.
Algorithm
- Primary survey and vitals; IV access and monitors.
- Focused history/physical; identify red flags and likely etiologies.
- Order system-appropriate labs and imaging (see Investigations).
- Initiate guideline-based empiric therapy (see Pharmacology).
- Reassess response; arrange consultation and definitive management.
Clinical Synopsis & Reasoning
DVT should be considered in unilateral limb swelling, pain, and erythema, particularly with recent surgery, immobility, cancer, or prior VTE. Use Wells score to categorize probability and apply D‑dimer in low/intermediate risk; duplex ultrasonography confirms diagnosis. Evaluate for PE symptoms and bleeding risk to plan therapy.
Treatment Strategy & Disposition
Anticoagulate with DOACs for most patients, LMWH for cancer, and heparin/warfarin when DOACs are unsuitable. Consider catheter‑directed therapy for limb‑threatening iliofemoral DVT (phlegmasia). Plan duration based on provoking factors; provide compression for symptom control and counsel on recurrence risks. Outpatient management is appropriate for reliable, low‑risk patients; admit if extensive clot burden, high bleeding risk, or comorbidity.
Epidemiology / Risk Factors
- Cytotoxic chemotherapy, neutropenia; lines
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|---|---|---|
| CBC with diff | Cytopenias/leukocytosis | Abnormal counts | |
| Coags | Bleeding/clotting | Abnormalities | |
| Smear | Morphology | Abnormal cells |
Initial Anticoagulant Choices
| Agent | Initial Dosing | Notes |
|---|---|---|
| Apixaban | 10 mg BID ×7 d, then 5 mg BID | No parenteral lead-in |
| Rivaroxaban | 15 mg BID ×21 d, then 20 mg daily | Take with food for 15/20 mg doses |
| LMWH → warfarin | Therapeutic LMWH bridge until INR 2–3 | Cancer/pregnancy considerations |
Pharmacology
| Medication | Mechanism | Onset | Role in Therapy | Limitations |
|---|---|---|---|---|
| Enoxaparin (LMWH) | Xa>IIa inhibition | Hours | Initial AC | Avoid severe renal failure |
| Apixaban/Rivaroxaban | Factor Xa inhibition | Hours | Outpatient/inpatient therapy | Bleeding; interactions |
| Warfarin (selected) | Vitamin K antagonist | Days | Mechanical valves/antiphospholipid | INR monitoring |
Prognosis / Complications
- Tied to depth/duration of neutropenia and comorbidities
Patient Education / Counseling
- Explain red flags and when to seek emergent care.
- Reinforce medication adherence and follow-up plan.
Notes
Consider cancer screening per guidelines; evaluate for thrombophilia testing only in selected patients where results affect management.