Incidence, clinical characteristics, and long-term prognosis of travel-associated pulmonary embolism.
ABSTRACT Prolonged air travel is considered a risk factor for pulmonary embolism (PE). The clinical characteristics as well as the long-term prognosis of patients suffering from travel-associated PE ('economy-class syndrome', ECS) remain largely unknown. Owing to its proximity, our hospital is the primary referral centre for Frankfurt Airport, Europe's third-largest airport. The goal of our study was to follow-up all patients with ECS, who were admitted to our hospital between 1997 and 2006.
We systematically reviewed all medical charts from patients presenting with acute PE to our emergency room or intensive care unit (ICU) and performed a telephone follow-up on patients discharged alive. Together with the data provided from the statistics department of Fraport Inc., the operating company of the Frankfurt International Airport, we were also able to put the medical data in context with the corresponding number of passengers and flight distances. A total of 257 patients with acute PE were admitted to our emergency and ICU between 1997 and 2006. Out of these, 62 patients suffered from ECS (45 flight-associated PE and 17 from other travel-associated PE). ECS patients were prone to more haemodynamic relevant acute events, reflected by a higher rate of initial cardiopulmonary resuscitation (4.8% vs. 1.5%; P = 0.153) and higher percentage of massive PE (8% vs. 3%; P = 0.064). Nevertheless, intrahospital mortality was similar in both groups (ECS 4.8%, others 4.1%; P = 0.730). Interestingly, the long-term outcome of ECS patients was excellent (Kaplan-Meier analysis; P log-rank: 0.008 vs. other entities). In general, ECS was a rare event (one event/5 million passengers), where long-haul flights over 5000 km lead to a 17-fold risk increase compared with shorter flights.
Travel-associated PE was a common cause of PE in our hospital, with patients showing excellent long-term prognosis after discharge. The risk of ECS is rather low and strictly dependent on the flight distance.
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ABSTRACT: The true frequency of deep-vein thrombosis (DVT) during long-haul air travel is unknown. We sought to determine the frequency of DVT in the lower limb during long-haul economy-class air travel and the efficacy of graduated elastic compression stockings in its prevention. We recruited 89 male and 142 female passengers over 50 years of age with no history of thromboembolic problems. Passengers were randomly allocated to one of two groups: one group wore class-I below-knee graduated elastic compression stockings, the other group did not. All the passengers made journeys lasting more than 8 h per flight (median total duration 24 h), returning to the UK within 6 weeks. Duplex ultrasonography was used to assess the deep veins before and after travel. Blood samples were analysed for two specific common gene mutations, factor V Leiden (FVL) and prothrombin G20210A (PGM), which predispose to venous thromboembolism. Asensitive D-dimer assay was used to screen for the development of recent thrombosis. 12/116 passengers (10%; 95% CI 4.8-16.0%) developed symptomless DVT in the calf (five men, seven women). None of these passengers wore elastic compression stockings, and two were heterozygous for FVL. Four further patients who wore elastic compression stockings, had varicose veins and developed superficial thrombophlebitis. One of these passengers was heterozygous for both FVL and PGM. None of the passengers who wore class-I compression stockings developed DVT (95% CI 0-3.2%). We conclude that symptomless DVT might occur in up to 10% of long-haul airline travellers. Wearing of elastic compression stockings during long-haul air travel is associated with a reduction in symptomless DVT.The Lancet 06/2001; 357(9267):1485-9. · 39.06 Impact Factor
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ABSTRACT: To study risk factors for the development of air travel-related acute venous thromboembolism. A retrospective study of 254 patients admitted from 1988 to 1993 under the diagnosis of deep vein thrombosis (DVT) and/or pulmonary embolism (PE) identified 44 patients who developed symptoms during or after air flight. There were 24 males and 20 females with a mean age of 63 years. Flight times were 5-17 hours. Twenty-eight patients (63.6%) had DVT only, five patients (11.4%) PE only, and 11 patients (25%) DVT and PE. Ninety-five percent had extension of the thrombus above the calf: popliteal vein, 10 patients; superficial femoral vein, 13 patients; common femoral vein, six patients; and iliac vein, eight patients. Five patient-related risk factors were identified: history of previous DVT (34%), presence of chronic disease or malignancy (25%), hormone therapy (16%), recent lower limb injury (11%), and recent surgery or femoral catheterization (9%). We can speculate about the role of seven cabin-related risk factors: low humidity, hypoxia, diuretic effect of alcohol, insufficient fluid intake, smoking, "coach" position, and immobilization. In travelers with patient-related risk factors, the cabin-related risk factors are superimposed and may increase the risks for air travel-related acute venous thromboembolism. Active prophylaxis is recommended.Dermatologic Surgery 08/1996; 22(7):637-41. · 1.87 Impact Factor
Article: Thromboembolism and air travel.The Lancet 12/1988; 2(8626-8627):1501. · 39.06 Impact Factor