While sitting on an international flight, ever wonder what your risks are for a blood clot?

 

General Background:

It is estimated that the risk for a deep venous thrombosis (DVT) is 3-12% on a long-haul flight. However, the real incidence is difficult to evaluate, due in part to the lack of consensus about 1) diagnostic tests, and 2) the appropriate time frame to relate a venous thromboembolic event (VTE) to travel.

 

Risks Factors for VTEs on long-haul flights:

• General:
  • stasis: prolonged sitting & crowded conditions
  • relative hypoxia
  • dehydration

 

• Patient specific:
  • Age >40
  • Female gender
  • Use of estrogen-containing contraceptives/hormone replacement therapy
  • Obesity
  • Varicose veins in the legs
  • Family/personal history of prior VTEs
  • Active cancer/recent cancer treatment

 

Bottom Line:

• Even healthy individuals are at risk on long-haul (>8 hour) flights.
• The risk increases the longer the flight
• Current data does not appear to show a risk difference between economy and business class.
• Avoid dehydration and immobility
  • Exercise your legs/calf muscles
  • Drink plenty of fluid

References

http://www.cdc.gov/ncbddd/dvt/travel.html

 

Gavish I, Brenner B.  Air travel and the risk of thromboembolism.  Intern Emerg Med 2011 Apr;6(2):113-6.