Wellness Letter: Medical News

Travel: Avoiding Sticky Situations (in Your Circulation)
By Dr. Jannet Huang, MD, FRCPC, FACE

Being immobile for prolonged period of time is a well documented risk factor for deep vein thrombosis (blood clot in deep leg vein). Deep vein thrombosis (DVT) can lead to pulmonary embolism (blood clot traveling to the lungs) which is a serious complication. So the best approach to take is being proactive in preventing DVTs! Until the time when transporters depicted in Star Trek become reality, unfortunately traveling means being immobile in an aircraft or motor vehicle for some period of time.

Another risk factor for DVT is combined oral contraceptives (OCP -- birth control pills containing both estrogen and progestin) or oral hormone replacement therapy (HRT). One can argue that the only really proven increased risk from HRT is venous thromboembolism* (see below for more info on HRT). So for women who are taking either oral contraceptives or oral HRT, the tips provided below are that much more important. And guess what, smoking significantly increases a woman’s risk of DVT while on OCP or HRT. Yet another reason not to smoke!! Family history of blood clots also increases a person’s risk of developing venous thrombosis, but we are not able to modify the gene pool from which we originate…so we should focus on the modifiable risk factors and keep them to a minimum.

TRAVEL TIPS

1. Get up and walk around every hour.
   
   
2. If you are not able to get up, then exercise your feet and lower legs.
   
   
3. Use compression stockings (for those with significant edema, i.e., swelling of the lower limbs).
   
   
4. For prolonged flights (e.g. transatlantic or transpacific), holding off oral HRT for the day of travel can be considered.*
   
   
5. Take aspirin or other anti-clotting agents (coumadin, heparin, low molecular weight heparins etc)** as directed by your personal physician for specific conditions.

To read more about menopause and hormone replacement therapy, click here.

*HRT and venous thromboembolism…
Oral route of administration of estrogen raises the risk of venous thromboembolism due to the first pass effect through the liver. When estrogen is absorbed in the gastrointestinal tract, it travels to the liver via the portal circulation. Estrogen is extensively metabolized in the liver, and therefore larger doses are required orally when compared to transdermal administration to achieve the same blood levels. The liver increases its production of clotting proteins in the presence of this high level of estrogen associated with the oral route of administration. I therefore recommend the transdermal route for estrogen administration for most women seeking estrogen therapy. Options for the transdermal route include FDA approved patches, lotion and gels in addition to custom-compounded preparations (creams and gels). I will also take this opportunity to remind women on oral estrogen therapy to check with their physicians regarding the need to hold estrogen therapy around the time of certain elective surgical procedures when prolonged immobilization is anticipated. Usually other DVT prophylaxis strategies are implemented as well in the hospital.

**Any modification (addition, omission) of medications or treatments must be discussed with your own personal physician to determine whether these changes are appropriate for you as an individual.

—July 2005