Economy class syndrome
Deep Vein Thrombosis (DVT) is a well-known and severe condition, and the leading cause of death from pulmonary embolism.
The annual incidence of Thrombo Embolic Disease in the Caucasian population is 1 to 2 per 1000.
Cases of DVT have been described during air travel without attracting the attention of the medical profession or airlines, until the death of a 27-year-old woman at Heathrow airport after a flight from Australia.
Risk factors associated with air travel include immobilization, reduced local pressure and dehydration [1].
According to the conclusions of the Geneva meeting, long-haul air travel is unquestionably a risk factor for venous thrombosis in predisposed individuals.
Prevention
No systematic prevention should be proposed for flights of less than 4 hours, apart from the possible wearing of elastic medical compression socks, which is always recommended to avoid oedema.
For flights longer than 4 hours (8 hours according to the recommendations of the American College of Chest Physicians) [2] :
In patients with no personal history of DVT or known familial thrombophilia, it is recommended to (grade 1C) :
- Avoid wearing tight-fitting clothes.
- Do not consume alcoholic beverages.
- Avoid hypnotics (and the combination of alcohol and hypnotics).
- Wear elastic medical compression socks of 15 to 20 mm Hg.
- Regularly rotate and dorsi-flex both feet, avoiding crossing the legs.
- Make forced inspiratory and expiratory movements.
- Drink a glass of water every hour.
- Getting up every 2 or 3 hours to take a few steps in the corridor.
In patients with a history of recent or recurrent DVT, known and documented familial thrombophilia, advanced post-thrombotic disease, reduced mobility (gonarthrosis, coxarthrosis, disabling neurological disease) or progressive cancer, we recommend the same healthy lifestyle rules as described above, in combination with :
- Medical elastic compression with socks of 20 to 30 mmHg.
- A prescription for a preventive dose of Low Molecular Weight Heparin (LMWH). The subcutaneous injection should be given 1 to 2 hours before departure and repeated 1 to 2 hours before return (grade 2C).
- According to coagulation experts, aspirin has no preventive action on the venous system (grade 1B).
In the LONFILT study [2], of 467 subjects at risk of DVT, no thrombosis was observed during prophylaxis with LMWH (1,000 IU per 10 kg), whereas a thrombotic episode occurred in 3.6% of cases with aspirin and 4.8% in the absence of prophylaxis.
In patients with recent DVT, air travel will only be authorized after 10 days of anticoagulation with effective doses of LMWH or VKA, with 2 consecutive INR values between 2 and 3.
In patients who have had a semi-recent thromboembolic episode and are still taking VKAs, it is recommended to check the INR the week before the flight, and to prescribe elastic medical compression socks of 20 to 30 mmHg.
Bibliography
- F.Clheir, thromboembolic disease of air travel. ELSEVIER MASSON 20122.
- KEARON C, KAHN S, AGNELLI G et al. Antithrombotic therapy forvenous thromboembolic disease. American College of ChestPhysician (8e édition). Chest, 2008 ; 133 : 454S-545S.
- CEASARONE M. R, BELCARO G, NICOLAIDES A et al. Venous thrombis from Air Travel : The Lonflit study. Angiology, 2002 ; 53 : 1-6.