SAQ 211 – Vascular – D-dimer, superficial thrombophlebitis, and distal DVT

Question 9. D-dimer, superficial thrombophlebitis, and distal DVT.

a. Age-adjusted D-dimer

• It can be used when pre-test risk is not high.
• The cut-off is age in years multiplied by 10, giving 650 ng/mL for this patient.
• A result below the age-adjusted cut-off can safely exclude VTE in a low- or intermediate-risk patient.
• Evidence supports its safety and improves specificity in older patients.

b. Ultrasound indications in superficial thrombophlebitis

• Involvement of the upper third of the thigh.
• Clinical evidence of extension or a segment longer than 5 cm.
• Lower-limb swelling greater than expected from superficial phlebitis alone.
• Uncertain diagnosis.

c. Anticoagulation for superficial thrombophlebitis

• Affected segment longer than 5 cm.
• Thrombosis within 5 cm of the saphenofemoral or saphenopopliteal junction.
• A major ongoing thrombosis risk factor.

d. Anticoagulation for isolated distal DVT

• Leg immobilised in a cylindrical plaster or fibreglass cast.
• Prothrombotic haematological disorder or another continuing major thrombosis risk.

e. Anticoagulation options

• Enoxaparin.
• Dabigatran after initial parenteral anticoagulation.
• Rivaroxaban.
• Apixaban.

f. Ongoing management without anticoagulation

• Aspirin.
• Anti-embolic stocking.
• Repeat ultrasound in 3-7 days.
• Provide clear advice for urgent representation.