The risk factors that the experts addressed include sitting in a window seat, being old, pregnancy, and using oral contraceptives.
The new guidelines are called Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines".
Guideline co-author Mark Crowther, MD, Department of Medicine, McMaster University, Hamilton, Ontario, Canada, said:
"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. 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).
The swelling on the patient's right leg is a sign of deep vein thrombosis (DVT)
Some factors that may increase DVT risk in long distance air travelThe authors stress that the chances of developing DVT/PE (deep vein thrombosis, pulmonary embolism) during long-distance flights very small in the majority of cases. However, the following factors may contribute towards a higher risk if you are considering a long trip:
- Being immobile
- Being obese
- Being pregnant
- Having a history of DVT/PE, or a known thrombophilic disorder
- Having experienced a recent trauma
- Having some type of malignant cancer
- Having undergone a recent surgical intervention
- Sitting by the window
- Using oral contraceptives (estrogen use)
Tips for passengers at high risk of DVT/PEIf you are already at high risk of DVT/PE, the following recommendations are made by ACCP if you are on a long-haul flight (over six hours long):
- do calf stretching exercises
- get up and walk around frequently
- if you can, sit on an aisle seat
- use compression stockings, the below-knee graduated compression ones
Antithrombotic agents - their usage on long haul flights by people at high risk of DVT/PE should be considered on an individual basis. These types of medications have adverse effects, and the doctor needs to decide whether the benefits are greater than the risks.
Dr. Crowther said:
"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. Most passengers who do develop a DVT/PE after long-distance travel have one or more risk factors."
Non-flight issues covered in the new guidelinesThe guidelines include over 600 recommendations regarding the treatment, diagnosis and prevention of thrombosis. It covers issues concerned with pregnancy, cardiovascular disease, stroke, atrial fibrillation, orthopedic surgery, surgery in general, neonates and children.
The authors stress that doctors need to carefully assess a patient for DVT/PE risk before prescribing or administering prevention therapies.
Guidelines Panel Chair Gordon Guyatt, MD, FCCP, said:
"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. The decision to administer DVT prevention therapy should be based on the patients' risk and the benefits of prevention or treatment."
ACCP Antithrombotic Guidelines, 9th edition
Written by Christian Nordqvist