Venous thrombosis after travel

August 22, 2006

Several types of travel increase risk of venous thrombosis

Traveling for more than 4 hours by air, car, bus or train is associated with an increased risk of venous thrombosis. In a large study (the MEGA study) of nearly 2000 people with a first thrombosis in the Netherlands, Dr Suzanne Cannegieter and colleagues from the Leiden University Medical Center looked at the risk factors for thrombosis compared with their partners, who did not have thrombosis. The results, published in the international open-access medical journal PLoS Medicine, showed that 233 of the people with thrombosis had traveled for more than 4 h in the 8 weeks preceding the event. Although the overall risk of developing thrombosis is still low, traveling in general was found to increase the risk of venous thrombosis 2-fold. The risk was highest in the first week after traveling, and the overall risk of flying was largely similar to the risks of traveling by car, bus, or train.

In particular groups of people the risk was increased. For example, the risk was up to 8-fold in people who also had a specific mutation in one of the genes involved in clotting (factor V Leiden); almost 10-fold in those who had a body mass index of more than 30 kg/m2; 4-fold in those who were more than 1.90 m tall; and more than 20-fold in those who used oral contraceptives. For air travel these findings of risk in particular groups were more apparent than for other modes of travel, and in addition, people shorter than 1.60 m had an almost 5-fold risk of thrombosis after air travel. However, the numbers of people in each of these groups was small and hence the estimates of risk must be interpreted carefully.

The authors conclude that the risk of venous thrombosis is moderately increased for all these modes of travel, and that in particular groups of people the risk is highly increased. The study could not show the mechanism of the increased risk, although the association of thrombosis with all types of travel, not just air travel, suggests that immobility is a key factor. Other mechanisms, such as reduced oxygen levels triggering clotting, may be involved in the particularly increased risk seen in air travel in some groups.

For those who have an increased risk, such as oral contraceptive users and individuals with factor V Leiden, the authors say that preventative measure such as exercises may be warranted. However, the study's results apply only to people younger than 70 y of age and it is likely that other characteristics exist that also increase the risk. These characteristics are being investigated in an ongoing study - the World Health Organization Research Initiative into the Global Hazards of Travel (WRIGHT).

Public Library of Science

---

---

	Extensive Venous Thrombosis in a Runner (The Physician and Sportsmedicine) by JTE Multimedia Although usually considered a disease of sedentary people, deep venous thrombosis can occur in active patients. Physical findings may be difficult to differentiate from those of muscle trauma, a Baker's cyst, or hematoma. A high index of suspicion must be maintained, because delay in making the diagnosis and initiating anticoagulation may have fatal consequences. Doppler flow studies are required in all cases of limb pain or swelling in runners when deep venous thrombosis is even remotely suspected, as in this case of a 40-year-old man who developed ankle and lower-leg pain 1 month after a 10-km run. If promptly treated, patients can make a safe return to training without adverse consequences. Family physicians are frequently consulted to evaluate running-related injuries. Leg...
	Diagnosing Deep Vein Thrombosis (Postgraduate Medicine) by JTE Multimedia Abstract: In this article, we discuss the approach for diagnosing deep vein thrombosis (DVT) in different patient populations. Clinical features and probability assessment guide further diagnostic tests. D-dimer testing is used as screening test; however, duplex ultrasound remains the primary confirmatory test. Computed tomography and magnetic resonance imaging are used only in select patient populations, such as when ultrasound results are equivocal, in patients suspected of central venous DVT, or as a part of combined protocol for diagnosis of pulmonary embolism. Contrast phlebography and plethysmography do not have much of a role during routine diagnosis of DVT. Original Publication Date: March 2010
	Venous Thromboembolism Following Vigorous Deep Tissue Massage (The Physician and Sportsmedicine) by JTE Multimedia Venous thromboembolism (VTE) is an increasing public health concern, in part because of lack of awareness among patients and physicians. Nonpenetrating trauma to the legs may be an under-recognized potential risk factor for VTE. We report a case of VTE following vigorous deep tissue massage in a previously healthy 67-year-old man with no other identifiable risk factors. The etiology, risk factors, and implications for the prevention and detection of VTE are reviewed. There are few other published reports of VTE associated with massage, but under-reporting seems likely. Vigorous massage or any equivalent trauma to the legs should be considered and evaluated as a possible risk factor for VTE, especially in older adults. Additional research is needed to clarify the risks associated with...
	IMPROVING DETECTION OF VENOUS THROMBOEMBOLISM: New technology holds promise for early, precise diagnosis (Postgraduate Medicine) by JTE Multimedia Deep venous thrombosis and pulmonary embolism represent disorders of hemostasis that fall within the larger classification labeled venous thromboembolism. The mortality rate for these disorders is about 15%, and death is often linked with missed or delayed diagnosis, which points to the importance of clinical suspicion in successful management. During the last decade, new technology has greatly enhanced the accuracy of diagnosis. This article discusses some of the new diagnostic modalities and explains when and why they might be helpful in clinical practice. Gill P, Nahum A. Improving detection of venous thromboembolism: new technology holds promise for early, precise diagnosis. Original Publication Date: September 2000
	Improving Venous Thromboembolism Performance: A Comprehensive Guide for Physicians and Hospitalists (Hospital Practice) by JTE Multimedia Venous thromboembolism (VTE) is a major potentially preventable cause of hospital deaths and is associated with a substantial clinical and economic burden in the United States. Despite the availability of effective thromboprophylactic agents and evidence-based management guidelines, VTE prophylaxis is commonly underused and inappropriately prescribed in real-world practice. Several US organizations have developed quality-improvement initiatives to close the gap between guideline recommendations and clinical practice, and thus reduce VTE-associated morbidity and mortality. The Surgical Care Improvement Project and the National Quality Forum, in collaboration with The Joint Commission, have developed performance measures to allow assessment of the quality and appropriateness of VTE...
	Venous Thromboembolism: A Clinical Review (Postgraduate Medicine) by JTE Multimedia Abstract: Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism, represents a significant source of morbidity and mortality. It is readily diagnosed with noninvasive modalities when there is a clinical suspicion. Most patients presenting with signs and symptoms of DVT have well-known risk factors, such as a history of VTE, malignancy, recent illness, or immobilization. A subset of individuals with idiopathic VTE have no readily identifiable risk factors. Therapeutic anticoagulation is the cornerstone of management in all patients with VTE. Adjunctive measures, such as thrombolysis and the use of vena cava filters, are indicated in select cases. The ideal duration of anticoagulation is unknown, but is often maintained long-term in patients with acquired...
	Handbook on Cerebral Venous Thrombosis (Frontiers of Neurology and Neuroscience) by V. Caso (Editor), G Agnelli (Editor), M. Paciaroni (Editor) Cerebral veins contain about 70 per cent of the total cerebral blood volume, but cerebral venous thrombosis (CVT) occurs about a thousand times less often than arterial stroke. CVT affects mostly young adults and children, and in about one quarter of cases the cause remains unknown. Written by international experts, this publication is dealing with epidemiology, risk factors, coagulation disorders, clinical presentation - especially focusing on headache, current neuroradiological treatment, complications and long-term prognosis of CVT. The book covers the full spectrum of CVT pathogenesis and offers a new and effective approach to improve earlier diagnosis, recognize new risk factors and to identify the most severe manifestations, which require more aggressive treatments.Neurologists,...
	The Aetiology of Deep Venous Thrombosis: A Critical, Historical and Epistemological Survey by P. Colm Malone (Author), Paul S. Agutter (Author) What we now call ‘deep venous thrombosis’ (DVT) has been elucidated by a diversity of investigative approaches during the past four centuries. The authors of this book survey the history of the field and ask: why has one of these perspectives – the haematological/biochemical – come to dominate research into the causation of DVT during the past 50 years and to exclude alternatives? In answering this question, the authors show that the current consensus model is conceptually flawed.
	Venous Thrombosis: From Genes to Clinical Medicine: The Molecular Genetics of an Archetypal Multigene Disorder (Human Molecular Genetics) by Dermot M.F. Cooper (Author), M. Krawczak (Author) Thrombotic disease is a major cause of death and disablement in Western society. The most common cause is an inherited defect in one of the many genes encoding a protein which is involved in clotting, its regulation or the process of clot dissolution, fibrinolysis. Venous Thrombosis: From Genes to Clinical Medicine presents our current knowledge of potential prothrombotic protein abnormalities, together with a clear and concise views of the roles these proteins play in haemostasis, and the use of molecular techniques in the analysis and diagnosis of inherited defects. Each chapter describes a specific protein deficiency, with information on protein structure, function and biochemistry, gene structure and expression, as well as epidemiological and molecular genetic aspects of the...
	Venous Thrombosis and Pulmonary Embolism: Diagnostic Methods (Methods in Haematology) by Jack Hirsh (Editor)