Makindo Medical Notes

Related Subjects: | Assessing Breathlessness | Respiratory Failure | Pulmonary Embolism | Deep Vein Thrombosis | DVT/PE in Pregnancy | CTPA

Initial DVT Management Summary

Initial DVT Management Summary

Clinical assessment: If DVT is suspected, use the Wells score: Wells Score ≤ 0: Low/Unlikely Risk Group, DVT Prevalence 5% Wells Score 1-2: Moderate Risk Group, DVT Prevalence 17% Wells Score ≥ 3: High/Likely Risk Group, DVT Prevalence 17-53% Actions: If Wells Score 0-1: Check D-dimer If negative, DVT diagnosis is excluded; seek an alternative cause. If positive, arrange ultrasonography; treat if positive. If Wells Score ≥ 2: Do not check D-dimer; arrange ultrasonography. If negative, repeat ultrasound in one week.

About DVT

• Most pulmonary emboli (PE) originate as DVTs in the pelvic or leg veins.
• Failure to treat DVT can lead to PE and post-thrombotic syndrome.
• Prevention strategies in hospital settings include early mobilization, low molecular weight heparin (LMWH), and TED stockings.

Risk Factors

• General immobility (e.g., illness, stroke, neurological disorders)
• Post-operative state, malignancy
• Pelvic, orthopedic, or gynecological surgery
• Pregnancy, postpartum, and combined oral contraceptive pills (COCP)
• Inherited thrombophilia (Factor V Leiden, Protein C or S deficiency)
• Age > 60 years, smoking, obesity
• Recent travel > 4 hours within the past 2 weeks
• Congestive heart failure, hyperosmolar non-ketotic coma (HONK)

Risks Associated with COCP

• No combined pill: 5 DVT/PE per 100,000
• Second-generation combined pill: 15 DVT/PE per 100,000
• Third-generation combined pill: 25 DVT/PE per 100,000
• Pregnancy: 60 DVT/PE per 100,000

Clinical Presentation

• Calf pain, dilated veins, and erythema
• Homan’s sign – pain on dorsiflexion of the foot
• Positive tibial tap, obvious swelling
• Increase in calf circumference compared to the other leg

Investigations

• D-dimer test (only if low suspicion of DVT)
• Compression ultrasound (useful for proximal DVT, but may miss below-knee DVT)
• Venography (rarely performed now, but considered the gold standard)
• MRI (used in select cases but expensive)
• Thrombophilia screening in selected cases

Differential Diagnoses

• Venous thrombosis
• Calf hematoma
• Ruptured Baker’s cyst
• Cellulitis or soft tissue infection
• Lymphatic obstruction
• Congestive heart failure (CCF)/cor pulmonale
• Rupture of the gastrocnemius muscle
• Low albumin

Wells Score for DVT

• Paralysis, paresis, or recent orthopedic casting of the lower extremity (1 point)
• Recently bedridden (more than 3 days) or major surgery within the past 4 weeks (1 point)
• Localized tenderness along the deep vein system (1 point)
• Swelling of the entire leg (1 point)
• Calf swelling greater than 3 cm compared to the other leg (measured 10 cm below the tibial tuberosity) (1 point)
• Pitting edema greater in the symptomatic leg (1 point)
• Collateral non-varicose superficial veins (1 point)
• Active cancer (treatment within 6 months) (1 point)
• Alternative diagnosis more likely than DVT (e.g., Baker's cyst, cellulitis) (-2 points)

Wells Score Interpretation

• 3-8 Points: High probability of DVT
• 1-2 Points: Moderate probability
• -2-0 Points: Low probability

No decision rule should override clinical judgment. A high suspicion for DVT should prompt imaging, regardless of the Wells score.

Management

• Most ambulatory patients with DVT can be managed as outpatients.
• Start weight-adjusted LMWH (e.g., Enoxaparin 1 mg/kg twice daily) for 5 days if DVT is suspected.
• Once DVT is confirmed by imaging, start Warfarin (3-5 mg daily) along with LMWH until therapeutic INR is reached.
• Streptokinase may be used for large proximal DVTs.
• Below-knee DVT: 6 weeks of Warfarin.
• DVT or PE with no obvious cause: 6-12 months of Warfarin.
• DVT with a one-off cause: 3 months of Warfarin.
• Recurrent DVT/PE may warrant lifelong Warfarin.
• Consider thrombolysis for massive iliofemoral DVT with limb-threatening gangrene risk.

References

• Wells PS, Anderson DR, Bormanis J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997;350(9094):1795-8.