DVT is a condition of clotting in the deep veins of the legs. This can cause swelling of the legs. Pieces of the clots can break off and go past through the legs and into the lungs (pulmonary embolism, PE) and cause shortness of breath, heart failure, and even death. This has been recognised in association with international airline travel. DVT is more common with hospital admissions, after surgery and after trauma. There are things that you could consider to minimise the risk of DVT during travel:

General things to do

1. Most airline magazines now have leg and arm exercises you can do in the seat.
2. Keep well hydrated with water.
3. Minimise alcohol consumption.
4. Avoid sedatives.
5. Walk around the plane reasonably frequently, e.g. once every couple of hours. This is what everyone advises, although I am not sure how practical it is.

Stockings
Wear support stockings on all international travel. A Class 2 (20mm to 30mm of mercury) below knee sock for men and women, or a Class 1 (10mm-20mm of mercury) pantyhose for women is recommended. It is not clear that this will be cost effective for young people on a population basis, but individually it is my current recommendation.

Aspirin
I do not recommend taking Aspirin to prevent deep venous thrombosis. It’s effectiveness is low for this indication and there is a small, but definite risk of complications from Aspirin. Patients who are on Aspirin for other reasons should continue taking Aspirin.

Heparin
Heparin injections are available, e.g. Clexane 40 mg SC @ 24 hours, in preloaded syringes and are easy for the patient to administer. Treatment on the day before, day of, and day after travel is recommended. Your local general practitioner can prescribe these. You will need a letter indicated that you are taking these for a medical reason. With security issues, you need only carry on board 1-2 syringes for international and none for domestic air travel. On board injections need to be declared (in named plastic bag).

Warfarin
This deserves a special mention because it is probably the most effective way of preventing deep venous thrombosis. It is not our practice currently to recommend standard or low dose Warfarin prophylaxis for airline travel in the absence of another medical indication.

Types of travel
The above comments apply mainly to international airline travel or transcontinental, i.e. Melbourne to Perth (greater than 3 hours travel). If you are happy to wear support stockings on any airline flight, I think this is quite reasonable. Prolonged car or bus travel can also cause a deep venous thrombosis. The risk seems to be a lot less. I suppose this is because people stop and get out of the mode of transport for a couple of hours.

Risk factors for an increased risk of DVT when travelling:

1. Over 60 year old
2. Cardiac failure
3. Cancer
4. Previous DVT/PE
5. 5. Thrombophilia
6. Recent surgery
7. Varicose veins

Please remember:

1. The risk of driving to the airport is probably an order of magnitude greater than the risk of DVT on the plane for most patients.
2. The full story on DVT/PE, “Economy Class Syndrome” is far from clear.
3. These comments are general in nature and are not meant as specific medical advice for any particular patient.
4. Your usual medical practitioner may have other advice.