Economy Class Syndrome (or Travellers' Thrombosis [1] ) is the occurrence of deep vein thrombosis in air travellers.[2] The term was first coined in the late 1980s[3] when it turned out that people who had traveled long distances by airplane were at an increased risk of thrombosis, especially deep venous thrombosis and its main complication, pulmonary embolism. Although all these diseases had been recognised for a long time [4] [5], the possibility of litigation against airline companies brought them into the limelight when this "syndrome" was reported.
Contents |
[edit] Cause
The mechanism for thrombosis in travellers is probably due to a combination of immobilisation, dehydration and underlying risk factors. Additional environmental factors during air travel may also play a role. [6] [1] Although the problem has been specifically related to air travel it would appear that the problem is linked to immobility and that all travellers, including travellers by bus, train and car, are equally at risk.[7]
Patients with diseases that predispose them to thrombosis, such as antiphospholipid syndrome or cancer, are at a much greater risk. The highest risk groups include the elderly, pregnant women, those suffering serious medical conditions such as cancer and those with recent orthopedic surgery (legs or knees). [8]
The WRIGHT (World Health Organisation Research Into Global Hazards of Travel) project has investigated the association between travel and venous thromboembolism (VTE), a term which covers deep vein thrombosis (DVT) and/or pulmonary embolism (PE). [9] This has reported that the risk of VTE approximately doubles after a long–haul flight (>4 hours) and also with other forms of travel where travellers are exposed to prolonged seated immobility. Risk increases with the duration of the travel and also in passengers having other known risk factors of VTE.
[edit] Prevention
Prevention consists of adequate hydration[2](drinking, abstaining from alcoholic beverages and caffeine), moving around and calf muscle exercises[2]. Any traveller with significant risk factors should seek medical advice and be considered for prophylaxis. Aspirin is not recomended.[8] Severe risk for thrombosis can prompt a physician to prescribe injections with low molecular weight heparin (LMWH), a form of prophylaxis already in common use in hospital patients.[8]
There is clinical evidence to suggest that wearing compression socks whilst traveling also reduces the incidence of thrombosis in people on long haul flights. A randomised study in 2001 compared two sets of long haul airline passengers over the age of 50; one set wore MediUK mediven travel compression hosiery the other did not. The passengers were all scanned and blood tested to check for the incidence of DVT. The results showed that asymptomatic DVT occurred in 10% of the passengers who did not wear compression socks, whilst the group wearing compression had no DVTs. The authors concluded that wearing elastic compression hosiery reduces the incidence of DVT in long haul airline passengers. However it is worth noting that an asymptomatic DVT incidence of 10% is much higher than the expected symptomatic rate (alternatively estimated at less than 0.25% [10]) and wearing compression stocking was also associated with symptomatic superficial thrombophlebitis in 4%. [11]
A Cochrane review in 2006 concluded that passengers can expect a substantial reduction in the incidence of symptomless DVT and leg oedema if they wear compression stockings.[12]
[edit] See also
[edit] References
- ^ Bagshaw M (2001). Traveller's thrombosis: a review of deep vein thrombosis associated with travel. The Air Transport Medicine Committee, Aerospace Medical Association.. 72. pp. 848–851. PMID 11565823.
- ^ a b c Philbrick JT, Shumate R, Siadaty MS, Becker DM (2007). "Air travel and venous thromboembolism: a systematic review". Journal of general internal medicine : official journal of the Society for Research and Education in Primary Care Internal Medicine 22 (1): 107–14. doi:. PMID 17351849.
- ^ Cruickshank JM, Gorlin R, Jennett B. Air travel and thrombotic episodes: the economy class syndrome. Lancet 1988;2(8609):497-8. PMID 2900413.
- ^ Homans J (1954). "Thrombosis of the deep leg veins due to prolonged sitting". N Engl J Med 250 (4): 148–149. PMID 13119864.
- ^ Symington IS, Stack BH (1977). "Pulmonary thromboembolism after travel". Br J Dis Chest 71 (2): 138–140. PMID 861157.
- ^ Bendz B, Rostrup M, Sevre K, Andersen TO, Sandset PM (2000). "Association between acute hypobaric hypoxia and activation of coagulation in human beings". Lancet 356 (9242): 1657–8. doi:. PMID 11089830.
- ^ Ferrari E, Chevallier T, Chapelier A, Baudouy M (1999). "Travel as a risk factor for venous thromboembolic disease: a case-control study". Chest 115: 440-4. PMID 10027445.
- ^ a b c Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, Colwell CW; American College of Chest Physicians (2008). "Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)". Chest 133: 381S-453S. PMID 18574271.
- ^ World health organization (2007). WHO Research Into Global Hazards of Travel (WRIGHT) Project : final report of phase I.
- ^ Hirsh J, O'Donnell MJ (2001). "Venous thromboembolism after long flights: are airlines to blame?". Lancet 357 (9267): 1461-2. PMID 11377591.
- ^ Scurr JH, Machin SJ, Bailey-King S, Mackie IJ, McDonald S, Smith PD (2001). "Frequency and prevention of symptomless deep-vein thrombosis in long-haul flights: a randomised trial". Lancet 357 (9267): 1485–9. doi:. PMID 11377600.
- ^ Clarke MJ, Hopewell S, Juszczak E, Eisinga A, Kjeldstrøm M (2006). "Compression stockings for preventing deep vein thrombosis in airline passengers". Cochrane Database Syst Rev (2): CD004002. doi:.
[edit] External links
All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.)
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.
Privacy policy - About Wikipedia - Disclaimers - Fundraising
