As Travel Season Approaches, Physiotherapists Offer Tips On Preventing Deep Vein Thrombosis

The travel season is here and with it might come sitting in a stationary position for long car travel, extended flights or train rides. As travel becomes more popular and affordable, public concern has increased about the possible connection between long-haul travel and developing potentially-fatal deep vein thromboses (DVT) — formation of blood clots in the veins. Community concern regarding air travel and the potential increased risk of DVT is not a new subject. The first case reported in 1954 in the New England Journal of Medicine occurred in a doctor after a 14-hour flight.

Air travel has been linked with the development of DVT since the 1950s with a number of plausible explanations as causation; however, the risk associated with DVT might have been overlooked or underemphasized, as the incidence could happen up to several weeks after air travel. In a study published in BMJ 2003; 327:1072, the risk of venous thromboembolism was reported to be highest within two weeks of a long-haul flight. The study concluded that the annual risk of venous thromboembolism was increased by 12 percent if one long-haul flight (traveling more than 10,000 km) is taken yearly.Contribution of immobility to development of DVT already has been established. A number of factors in aircraft cabins have been reported to increase the risk of air travelers developing DVT or PE (clots passing to the lungs where they may obstruct the blood flow and could result in death). These include immobility due to cramped seating positions, possible dehydration due to consumption of alcoholic drinks and other diuretics such as tea and coffee, and the low humidity of the aircraft cabin, relative hypoxia and reduced barometric pressure.The overall risk of thrombosis after a long-haul flight is estimated to be about one in 2,000. For people with known risk factors the risk may be higher, but for those without other risk factors, it is likely to be very low and should be kept in perspective. The combination of immobility and personal risk factors potentially could be the reason for long-travel-associated DVT in some but not all travelers.Six to 20 percent of the total population is thought to have some degree of increased clotting tendency, in other words has risk factors for developing DVT (BMC Cardiovascular Disorders 2004, 4:7). This indicates there might be a “natural” underlying incidence of DVT in the general population associated with their personal factors, which put them at higher risk.The good news is there are preventative measures that potentially could reduce this risk. In health care, prevention often has been associated with having prophylaxis measures in place. Movement and exercise intervention, which oppose one of the major contributing factors to DVT (immobility), is a “prophylactic” measure in this situation.”As physical therapists and experts in movement, we have been able to guide and provide movement interventions and exercises as prophylactic measures in prevention of this potentially killer condition,” says Zahra Ghasemi, PT, MS, physical therapy supervisor at Cedars Sinai Medical Center. This intervention is more critical in individuals considered at risk for DVT including those:

Over 40 years old
Who have already experienced blood clots
With a family history of blood clots
Who have/had cancer
With certain blood diseases
Being treated for circulation problems or heart failure
Recovering from recent surgery (especially hips or knees)
With an inherited clotting tendency
Who are pregnant
Who are new mothers
Taking the contraceptive pill
On hormone replacement therapy (HRT)

Reducing the riskConsider the following risk-reduction strategies before traveling if you have any of the listed risk factors:

Wear loose clothing.
Find a comfortable position in your seat and recline if possible.
Do not cross your legs when sitting (doing so compresses blood vessels).
At stopovers and refueling points, leave the plane and walk as much as possible.
Move at regular intervals to increase blood flow through the veins.
Walk around on long flights (when permitted).
Drink plenty of water.
Avoid excessive alcohol, as it has dehydrating effects.
Postpone long-haul flights for three months after hip or knee replacement surgery.
Learn and apply in-seat exercises to ensure circulation is kept active with no blood stasis.
Use of elastic/compression stockings has been recommended.
Women taking contraceptive pills or hormone replacement therapy should regularly do the exercises described on APTA’s Web site to help reduce the risk, as well as consider the use of elastic/compression stockings.
Obtain additional information from your physical therapist or gynecologist if pregnant or nursing.
Take along current prescriptions for all essential medicines.
Ensure that there is adequate medical insurance for your trip.(Source: Cedars Sinai Medical Centre : April 2007.)