Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New DVT guidelines: No evidence to support 'economy class syndrome'

Oral contraceptives, sitting in a window seat, advanced age, and pregnancy increase DVT risk in long-distance travelers

New evidence-based guidelines from the American College of Chest Physicians (ACCP) address the many risk factors for developing a deep vein thrombosis (DVT), or blood clot, as the result of long-distance travel.

These risk factors include the use of oral contraceptives, sitting in a window seat, advanced age, and pregnancy. The Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, published in the February issue of the journal CHEST, also suggest there is no definitive evidence to support that traveling in economy class can lead to the development of a DVT, therefore, dispelling the myth of the so-called "economy class syndrome."

"Traveling in economy class does not increase your risk for developing a blood clot, even during long-distance travel; however, remaining immobile for long periods of time will," said guideline co-author Mark Crowther, MD, Department of Medicine, McMaster University, Hamilton, Ontario, Canada. "Long-distance travelers sitting in a window seat tend to have limited mobility, which increases their risk for DVT. This risk increases as other factors are present." DVT is a serious condition that can lead to a potentially fatal blockage in the lung known as a pulmonary embolism (PE).


Although developing a DVT/PE as the result of long-distance travel is unlikely in most cases, the guidelines note that for long-distance flights, the following factors may increase your risk of developing a DVT/PE and related complications:

Previous DVT/PE or known thrombophilic disorder
Recent surgery or trauma
Advanced age
Estrogen use, including oral contraceptives
Sitting in a window seat
Conversely, the guidelines suggest there is no definitive evidence to support that dehydration, alcohol intake, or sitting in economy class (compared with sitting in business class) increases your risk for developing a DVT/PE resulting from long-distance flights.


For travelers on flights of 6 hours or more who have an increased risk for DVT/PE, the ACCP recommends frequent ambulation, calf muscle stretching, sitting in an aisle seat if possible, or the use of below-knee graduated compression stockings (GCS). For long-distance travelers who are not at increased risk for DVT/PE, the guidelines suggest against the use of GCS. In addition, the guidelines suggest against the use of aspirin or anticoagulant therapy to prevent DVT/PE in long-distance travelers. For travelers who are considered to be at particularly high risk for DVT/PE, the use of antithrombotic agents should be considered on an individual basis because the adverse effects may outweigh the benefits.

"Symptomatic DVT/PE is rare in passengers who have returned from long flights; however the association between air travel and DVT/PE is strongest for flights longer than 8 to 10 hours," said Dr. Crowther. "Most passengers who do develop a DVT/PE after long-distance travel have one or more risk factors."


In addition to long-distance travel, the ACCP guidelines include more than 600 recommendations for the prevention, diagnosis, and treatment of thrombosis, addressing a comprehensive list of clinical conditions. These clinical conditions include medical, surgery, orthopedic surgery, atrial fibrillation, stroke, cardiovascular disease, pregnancy, and neonates and children, among others. Key advances in this edition of the guidelines include a stronger focus on risk stratification of patients, which suggests clinicians should consider a patient's risk for DVT/PE before administering or prescribing a prevention therapy.

"There has been a significant push in health care to administer DVT prevention for every patient, regardless of risk. As a result, many patients are receiving unnecessary therapies that provide little benefit and could have adverse effects," said Guidelines Panel Chair Gordon Guyatt, MD, FCCP. "The decision to administer DVT prevention therapy should be based on the patients' risk and the benefits of prevention or treatment." The new guidelines also take a more patient-focused approach by considering patient values and preferences regarding antithrombotic therapy and prevention.

The guidelines are endorsed by the following medical associations: the American Association for Clinical Chemistry, American College of Clinical Pharmacy, American Society of Health-System Pharmacists, American Society of Hematology, International Society of Thrombosis and Hemostasis, and the American College of Obstetrics and Gynecology (pregnancy article only).

For more information about the guidelines and accompanying clinician resources, visit and follow #AT9 on Twitter. Patient resources related to the guidelines are available through OneBreath, an initiative of The CHEST Foundation, the philanthropic arm of the ACCP.


The ACCP represents 18,400 members who provide patient care in the areas of pulmonary, critical care, and sleep medicine in the United States and more than 100 countries throughout the world. The mission of the ACCP is to promote the prevention, diagnosis, and treatment of chest diseases through education, communication, and research. CHEST is the official peer-reviewed publication of the ACCP. More than 30,000 readers worldwide turn to CHEST in print and 400,000 people view CHEST online each month for the latest in chest-related medicine. For more information about the ACCP, visit or follow the ACCP via social media at and @accpchest.

Jennifer Stawarz | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>