Air Travel-Associated Venous Thromboembolism

Abstract

Long-distance air travel is increasing and cases of venous thromboembolism (VTE) following air travel have attracted both considerable public attention and legal claims against airlines. VTE is a common disorder worldwide with a notably high incidence in older individuals. Many biochemical factors that lead to, or accentuate, thrombus formation are associated with increased risk of VTE. These factors include thrombophilia, activated protein C resistance and factor V Leiden, prothrombin gene mutation, antiphospholipid antibodies, protein S and protein C deficiencies, and methylene tetrahydrofolate reductase polymorphism and homocysteinemia. Individual physical characteristics including age, weight and height are significant for personal risk of VTE as are other factors such as use of oral contraceptives in women. In the case of air travel-related venous thrombosis, superimposed upon these individual factors are the environmental factors directly related to air travel. Travel-related factors include stasis associated with prolonged periods of immobility, physiological stresses resulting from exposure to the cabin environment (low humidity and hypoxia) in long-haul flight and other in-flight factors. It is suggested that passenger behavior (movement, avoidance of dehydration and of alcohol) and appropriate pharmacological prophylaxis for high-risk travelers can reduce the likelihood of VTE. Physical prophylaxis (use of compression stockings or in-flight exercise devices) may also be of general benefit to passengers. It is recommended that airlines become more proactive in educating passengers concerning the dangers of VTE and in promoting passenger actions that can reduce risk. Airlines should also work to avoid cramped seating conditions (seat size and pitch) that contribute to prolonged immobility. Governments and regulatory authorities should mandate the provision of adequate seating conditions and a good cabin environment and should support studies that will define risks and determine the efficacy of protocols to minimize dangers of VTE. Increased long-haul air traffic and an aging population suggest that travel-related VTE may present a growing healthcare threat and has highlighted a need for additional biomedical research into the causes and potential solutions to this problem.

Increased frequency of cardioembolism and patent foramen ovale in patients with stroke and a positive travel history suggesting economy class stroke syndrome

“…2 6 Venous thrombosis and consequent pulmonary embolism after long-distance travel has been widely recognised and reported in the literature. [6][7][8][9] Recently, some reports described a possible association between long travelling and stroke through paradoxical embolism and designated this condition ''economy class stroke syndrome'' (ECSS). [10][11][12][13][14][15][16][17] On the basis of these reports, we questioned whether this clinical stroke condition can be relevant in the care of patients in a European stroke care centre.…”

Perioperative Care of Tourist-Patients

“…Recently we observed two tourist-patients with Factor V Leiden, one of them developed PE after surgery [50]. The physical factors related to these events are prolonged venous stasis associated with long periods of immobility, exposure to cabins with low humidity, and low concentrations of oxygen [51]. During the process of establishing a medical program for this patients it is important to instruct them to stick to the prophylactic guides to prevent DVT and PE that airlines recommend like performing exercises with their feet and legs, walk frequently through the cabin alleys, as well as using adequate elastic compression stockings, avoid alcohol and dehydration during the flight.…”

Effects of 6-h exposure to low relative humidity and low air pressure on body fluid loss and blood viscosity

“…Iqbal et al. () reported that individual factors (e.g., age, weight, oral contraceptives, medical history) and in‐flight factors contribute to air travel–related VTE. Flight factors related to VTE include immobility and the cabin environment, which is characterized by low relative humidity (RH), hypobaria, and hypoxia.…”

“…Increased incidence of venous thromboembolic events (VTE) following long-haul flights is now well documented (Boccalon et al, 2005), and the link between VTE and air travel has been discussed (Gavish and Brenner, 2011;Morio et al, 2005;Nicholson et al, 2003). Iqbal et al (2003) reported that individual factors (e.g., age, weight, oral contraceptives, medical history) and in-flight factors contribute to air travel-related VTE. Flight factors related to VTE include immobility and the cabin environment, which is characterized by low relative humidity (RH), hypobaria, and hypoxia.…”