Economy class syndrome: what is it and who are the individuals at risk?

Abstract

The term ‘economy class syndrome’ refers to the occurrence of thrombotic events during long-haul flights that mainly occur in passengers in the economy class of the aircraft. This syndrome results from several factors related to the aircraft cabin (immobilization, hypobaric hypoxia and low humidity) and the passenger (body mass index, thrombophilia, oral contraceptives or hormone replacement therapy, cancer), acting together to predispose to excessive blood coagulation, which can result in venous thromboembolism. Several risk factors, both genetic and acquired, are associated with venous thromboembolism. The most important genetic risk factors are natural anticoagulant deficiencies (antithrombin, protein C and protein S), factor V Leiden, prothrombin and fibrinogen gene mutations and non-O blood group individuals. Acquired risk factors include age, pregnancy, surgery, obesity, cancer, hormonal contraceptives and hormone replacement therapy, antiphospholipid syndrome, infections, immobilization and smoking. People who have these risk factors are predisposed to hypercoagulability and are more susceptible to suffer venous thromboembolism during air travel. For these individuals, a suitable outfit for the trip, frequent walks, calf muscle exercises, elastic compression stockings and hydration are important preventive measures. Hence, it is essential to inform about economic class syndrome in an attempt to encourage Brazilian health and transport authorities to adopt measures, in partnership with the pharmaceutical industry, to prevent venous thromboembolism.

COVID-19, long flights, and deep vein thrombosis: What we know so far

“…Other. According to the literature, non-O blood groups have higher plasma levels of von Willebrand factor and factor VIII, which may lead to an elevated risk for thrombosis [13].…”

The secret enemy during a flight: Economy class syndrome

“…This syndrome results from several factors related to the aircraft cabin (immobilization, hypobaric hypoxia, and low humidity) and to the passenger (such as obesity, thrombophilia, oral contraceptive use, hormone replacement therapy, and cancer) that act together, predisposing an individual to excessive blood coagulation, which can result in VTE (10,21). Several risk factors, both genetic and acquired, are associated with VTE.…”

The Awareness of Airline Passengers About the Risk of Deep Venous Thrombosis During an Aeroplane Flight

“…The common name in the past as the economy-class band is now rarely used, inter alia due to the fact that the occurrence of thrombosis is not only related to air travel in less convenient economy-class conditions. The term was first used in 1977 by Semington and Stack [1]. Venous thromboembolism, clinically manifested as deep vein thrombosis and pulmonary embolism, is still the third cause of death among vascular diseases.…”

“…Hypoxia reduces the fibrinolytic activity of endothelial cells and damages platelets, which causes hypercoagulability and leads to the release of vascular relaxing factors, which slow down the flow. Air humidity in aircraft cabins is only 10-20% (comparable to desert conditions) and promotes rapid dehydration by evaporation [1,6]. In addition, long-term immobilization reduces the flow in the lower limbs by up to 2/3, leading to blood stagnation.…”

“…The presence of individual risk factors significantly influences the overall risk of long-term immobilization during travel. The global assessment of the risk of venous thromboembolism in this population allows us to distinguish patients with a low, moderate, or high risk of thrombosis (Table 1) [1,[9][10][11].…”