ClotCare: Blood Clots, Stroke, Heart Attack
Friday, June 14, 2024
Home   |   DVT/PE   |   Blood Clots   |   Coumadin/Warfarin   |   New Patients   |   Self Testing   |   Email List   |   Donate

Pick a Topic:

Find info on a:

We subscribe to the HONcode principles of the HON Foundation. Click to verify.
ClotCare complies with the HONcode standard for trustworthy health
verify here.

ClotCare is a member of the Coalition to Prevent Deep Vein Thrombosis (DVT Coalition)  ClotCare is a member organization of the Coalition to Prevent Deep Vein Thrombosis. Click here to learn more about the Coalition to Prevent Deep Vein Thrombosis and DVT Awareness Month, which is held each March.

Air travel activates clotting more than immobilization alone, especially in patients with factor V Leiden (fVL) and/or oral contraceptive use

Henry I. Bussey, Pharm.D., FCCP, FAHA
April, 2006

Reference: Schreijer AJ, Cannegieter SC, Meijers JC, Middeldorp S, Buller HR, Rosendaal FR. Activation of coagulation system during air travel: a crossover study. Lancet. 2006 Mar 11;367(9513):832-8.

Investigators in the Netherlands evaluated the effects of air travel and prolonged immobilization on the ground on indicators of clotting activation in 71 patients (11 with fVL, 15 using oral contraceptives, 15 who had both fVL and used oral contraceptives, and 30 patients who did not have fVL and did not use oral contraceptives). The indicators of clotting activation that were measured before and after each intervention were thrombin-antithrombin complex (TAT), fragment 1+2 (F 1+2), and d-Dimer. These indicators were measured at base line and before and after 3 interventions: an 8 hr plane flight, an 8 hr movie marathon, and 8 hrs of "daily life situation." TAT was the indicator that exhibited the greatest increase of approximately 30% after the flight vs. decreases of 2% and 7.9% after the movie marathon and daily life situation, respectively. High responders for any of the indicators (defined as those whose indicator levels were at least 3 standard deviations above the mean value for the daily life situation period) were found in 17% of individuals after air travel vs. 3% after the movie marathon and only 1% after daily life situation. Four individuals were high responders for all three indicators after the flight, but no individuals were high responders for all three indicators after the movie marathon or daily life situation. The presence of fVL or oral contraceptive use increased the likelihood of having elevated indicators and the combination of both factors appeared to be at least additive. For example, 6 of 14 (43%) of patients with fVL and oral contraceptive use were found to be high responders after the flight vs.17% for the entire group. The authors suggest that the low air pressure and/or low oxygen level in planes during travel may increase the risk of clotting over that observed with immobilization on the ground. Further, patients with fVL and users of oral contraceptives may be at increased risk. Even so, the absence of fVL and oral contraceptive use does not exempt individuals from this risk as evidenced by the fact that the two women with the highest TAT levels after the flight did not have fVL and were not taking oral contraceptives.

Ask a question about blood clots or anticoagulant medications Have questions? Ask ClotCare. Send questions by email to

ClotCare is a 501(c)(3) non-profit organization generously supported by your tax-deductible donations and grants from our industry supporters.

Blood Clot Activities Calendar

New Postings:

Click here to view full list of new postings
ClotCare Home | New Postings | Patient Postings | Clinician Postings | Join Our Email List | Useful Web Links
CE Opportunities | Training Programs | DVT & PE Stories | Editorial Board | Financial Support
About ClotCare | DVT Coalition | Donate to ClotCare | Contact Us
Key topics discussed on ClotCare include: Blood Clots | Deep Vein Thrombosis (DVT) | Pulmonary Embolism (PE) | Atrial Fibrillation (A. Fib or AF) | Heart Attack | Stroke | Transient Ischemic Attack (TIA) | Mini Stroke | Bleeding Complications | Vascular Surgery | Surgical Blood Clot Removal | Warfarin | Coumadin | Lovenox | Low Molecular Weight Heparin (LMWH) | Heparin | Anticoagulants | Plavix | Aspirin | Antiplatelets | Blood Thinners
Copyright 2000-2018 by ClotCare. All rights reserved.
Terms, Conditions, & Privacy | Image Copyright Information
19260 Stone Oak Parkway, Suite 101 | San Antonio, TX 78258 | 210-860-0487
Send comments to
Friday, June 14, 2024