Deep Vein Thrombosis

Introduction

There have been individual case reports of deep vein thrombosis (DVT) and deaths from pulmonary emboli following air travel but the problem has also been noted following prolonged periods of immobility during long bus, train and car journeys.

Aggravating factors could be pressure from the edge of seats on the back of the leg, dehydration aggravated by caffeine, alcohol and sedation which may encourage immobility.

Predisposing Factors

Those with the following conditions may be at greater risk of DVT and should be assessed by their General Practitioner prior to travel.

  • A history of DVT within the last 5 years or if the likely reason for this DVT is still present.
  • Malignant disease or chronic debilitating illness especially those causing mobility problems.
  • Recent surgery or deep injuries (e.g. hip fractures).
  • Age over 60 years.
  • Pregnancy or less than 2 months after delivery.
  • Cardio-respiratory disease.
  • Oestrogen therapy (contraceptive and/or hormone replacement).
  • Raloxifene or tamoxifen therapy.
  • Varicose veins.
  • Obesity.
  • Thrombophilia especially when due to the presence of factor V Leiden mutation.

Preventive Measures

Awareness and general advice

There is general agreement that there should be greater public awareness of the risk and preliminary advice for those at low risk include, stretch and exercise the legs when possible, keep well hydrated, avoid excess alcohol and limit caffeine consumption.

Aspirin therapy

It is now generally accepted that there is no place for aspirin in the prevention of travel related thrombosis and the risks outweigh any possible benefits.

Compression stockings

The use of graded elastic compression stockings may reduce the risk of DVT. Travellers should ensure that they buy the correct type and size of stocking and know how to wear them correctly. There may be a small increase in the risk of superficial thrombophlebitis in those with varicose veins.

Low molecular weight heparin

Low molecular weight heparin should be considered for those with several risk factors (see above) such as long-distance travel, previous thrombosis, malignant disease, plaster cast or recent surgery. This preventive measure must be prescribed by the traveller's General Practitioner or hospital Specialist and used under their direction. It should be given as a single injection shortly before travel.