Following a review by The Lancet of the medical issues associated with commercial air travel, the European Society of Cardiology has reaffirmed its advice about the risks of venous thromboembolism (VTE), whose risk, according to The Lancet, is increased "up to four-fold" by long-haul flight.
Dr Steen Kristensen, Vice-president of the ESC, says: "Long distance flying is associated with an increase in deep venous thrombosis, which in some cases may lead to clotting of the lungs. People who are immobile, pregnant, taking contraceptive pills or have had venous thrombosis in the past are particularly at risk. To minimise the risk it is important to drink plenty of non-alcoholic fluid and to walk (exercise) before and during the flight. The use of compression stockings is for some travelers an important way of preventing deep venous thrombosis."
Studies cited by The Lancet suggest that the risk of VTE increases when flight duration exceeds four hours. This raised risk is related to immobility, dehydration, and reduced oxygen in the cabin, as well as to individual risk factors such as obesity, recent surgery and predispositions to thrombosis (thrombophilias).
On the subject of risk Professor Kurt Huber, ESC spokesperson on Thrombosis, writes: "Prone to thromboembolic risk are those with a history of venous thrombosis or pulmonary embolism, but also those with a history of atherothrombotic diseases (for example, myocardial infarction or stroke) and those with heart failure, atrial fibrillation, and physical immobilisation." Professor Huber adds that even healthy people may develop thrombotic problems on a long-distance flight, notably pregnant women, women taking oral contraceptives (especially if they smoke) and the elderly. Those with concerns, he adds, should ask their doctor about their individual risk and the applicability of preventive measures, including medication.