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Safety Alert 27 : Dangers of Deep Vein Thrombosis

What happened?

It has come to the attention of NOPSA that a number of expatriate workers travelling on long haul flights to facilities in Australia have been diagnosed with Deep Vein Thrombosis (DVT) soon after reporting to work on a facility.

What could go wrong?

DVT is a blood clot in one of the deep veins usually in the calf or thigh. In this part of the body, blood moves quite slowly and when a clot occurs, it can get stuck in the vein blocking the blood supply. Symptoms aren't always immediately obvious and a blood clot is not necessarily fatal. However, these blood clots can become dislodged and travel to the lungs or other areas, causing strokes, severe organ damage, or death.

When you sit for a long time without contracting the muscles in your legs, blood can pool in the veins resulting in DVT. Tightly packed seating, such as that found in the economy section of airlines, can restrict movement. However, it is the lack of movement rather than the lack of space that is the probable cause of DVT. Hence, business/first class travel need not necessarily provide the solution to the problem.

Doctors suspect that keeping legs stationary combined with dehydration interrupts the blood flow which causes clots, cutting off the supply of oxygen to various parts of the body.

Although DVT can affect anyone, certain groups are more at risk. Anyone who has any of the following can be considered to be at an increased risk of DVT:

• Previous personal history of DVT;
• Family history of DVT;
• Recent surgery or injury, particularly involving the legs;
• Active cancer;
• Overweight or obese;
• Women on hormone replacement therapy;
• Smoker;
• Older age; and
• Chronic disease, especially heart or lung disease and diabetes.

If you have multiple risk factors noted above you should take extreme care while travelling and possibly seek medical advice.

Key Lessons:

There are a few simple steps that can greatly reduce the chances of getting DVT. These are:

• Periodically stretch out and move your legs and ankles and massage your calves while seated to stimulate blood circulation, don't cross your legs;
• Remain hydrated, drink plenty of water or other non alcoholic fluids during your flight;
• Restrict excessive alcohol and coffee consumption during travel as it may cause dehydration;
• Avoid taking strong sleeping tablets or sedatives which may result in sitting without moving for long periods;
• Wear loose, non restrictive clothing during air travel; and
• If safe to do so, get up and walk around a least once an hour.

Most important, if after arriving to a facility or returning home you feel in any way unwell report immediately to a medic or medical practitioner.

Contact

For further information email:

alerts [at] nopsa.gov.au

and quote Alert 27.

Disclaimer: This safety alert is based on publicly available information and was written for general information only. The safety alert does not purport to be definitive and is not a substitute for advice from a general practitioner, qualified physician or counsellor.

Acknowledgements

Part of this information was originally published on CSIRO Minerals OHSE website http://www.minerals.csiro.au/safety/ecs.htm

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