VENOUS THROMBOSIS

Two forms of venous thrombosis are recognised:

• Thrombophlebitis: thrombosis in a superficial vein with an inflammatory reaction. Usually benign and self-limiting, but can be difficult to treat and slow to resolve. Diagnosis is usually obvious.
• Deep-vein thrombosis (DVT): primary thrombosis in an otherwise normal vein, with higher risk of pulmonary embolism. Causes pain, swelling, reddening, tenderness and superficial venous distension. Diagnosis is notoriously difficult.

Risk factors include pregnancy, sluggish peripheral circulation (e.g. immobility, hip replacement surgery), increased viscosity of blood, damage to vein.

Risk reduction

Preoperatively, consider stopping oral contraception 6 weeks before; weight loss, use of appropriate VTE prophylaxis (Do not regard aspirin or other antiplatelet agents as adequate).

All travellers intending to take long haul flights or other forms of travel where they will be seated for more than 4 hours should be advised to

• Avoid dehydration and excessive alcohol consumption
• Not to wear constrictive clothing around the waist or lower extremities
• Walk around the cabin regularly and as frequently as practical
• Regularly flex and extend ankles to encourage blood flow
• Seek medical advice if calf pain/ swelling/discomfort or respiratory problems during or after travel.

Travellers at increased risk of VTE should consider properly fitted, below the knee, graduated compression stockings. Aspirin is not recommended for the prevention of travel related VTE; for high-risk patients consider prophylaxis with low molecular weight heparin.