VENOUS THROMBOEMBOLISM

 Venous thromboembolism can be classified as: 

• 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.
• Pulmonary embolism (PE): caused by a blood clot dislodging from a vein and travelling to the lungs. This is a serious complication and can be life threatening. The most common feature is sudden onset of dyspnoea. 

Risk factors include

• History of DVT or PE
• Coagulation disorders
• Pregnancy or recent childbirth
• Malignancy
• Heart failure or recent MI 
• Recent surgery/injury  
• One or more significant medical conditions e.g. heart disease, diabetes, respiratory disease, inflammatory conditions, dehydration

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 occur 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.