DVT - Deep Vein Thrombosis
First recognised back in 1946, travel related DVT
is an added potential problem for 'at risk' travellers who are immobile
for extended periods of time. While the problem is often associated
with air travel, the risk is equally reported among those travelling
by car, coach and train.
What is Travel Related DVT?
A Deep Vein Thrombosis (DVT) is a clotting of the
blood in any of the deep veins - usually in the calf. If a clot
develops, it usually makes its presence known by an intense pain
in the affected calf. Medical attention should be sought immediately
if this occurs, especially after a long journey. In some cases this
can be fatal, if the clot breaks off and makes its way to the lungs
where it can then affect the lung's ability to take in oxygen.
What are the symptoms How will I know it is a DVT?
A DVT can occur some days or even weeks after a
trip. In most situations the person will have no symptoms and through
normal movement the clot will break up.
If the clot is larger it can cause an obstruction
and prevent the blood flowing through the veins. When this happens
a person might experience pain, redness and swelling in the calf
this pain is made worse when walking or standing. If these
symptoms are experienced you should seek medical help immediately.
Complications can occur if the cot breaks off and
travels to the lungs, blocking the flow of blood. Breathlessness
and chest pain can occur hours or days after the clot formation
in the calf. This is a potentially fatal condition and urgent medical
attention is required.
Who is at risk?
Most cases have at least 3 predisposing risk factors
- the risk increases as risk factors increase.
Very little established research exists in relation
to travel. However we do have a wealth of information from hospital
research specific to DVT. We already know that immobility for an
extended period of time can increase the risk of DVT with the following
factors being added risk factors:
- Travel for more than 3 hours in the four weeks
before and after surgery
- A personal or family history of DVT
- Active cancer or cancer treatment
- Recent surgery or leg surgery
- Existing clotting abnormality
- Obesity (BMI of above 30)
- Chronic or acute medical illnesses
- Hormones or the oral contraceptive pill
- Inflammatory bowel disease
- Varicose veins
- Pregnancy or 2 months post-partum
- Existing Cardiac problems or a history of cardiac
problems or stroke
- Severe infection
- Aged over 60
How many people are affected?
It is hard to establish just how many people are
affected by DVT after travel related activities, as no official
records are kept. However it is important to be aware that it is
a potential problem for those with risk factors, due to the evidence
we already have.
How can I reduce my risk?
Those in a high-risk category should see their travel
health advisor before they travel and discuss prevention.
Those at risk should try to exercise at least every
hour on long journeys. Exercise the calf muscles by rotating your
ankles, or making use of the commercially available exercise equipment.
The risk applies to any form of travel where you are routed to one
place for hours at the time.
Good hosiery will encourage circulation. However
it is important that you do not wear clothing that will cause a
restriction of circulation. Any hosiery should be measured properly
to ensure a suitable fit.
For long flights wear loose clothing. Due to the
change in atmospheric pressure in a plane, parts of your body can
expand due to increased gas! In the dry environment of a plane,
it is a well-documented fact that too much alcohol, tea and coffee
on flights can add to the problem of dehydration. It is therefore
very important to remain hydrated during a long flight by drinking
plenty of water and fruit juices.
In-Flight Stockings and DVT Socks
With much attention given over the potential risks
associated with Travel Related Deep Vein Thrombosis, it is not surprising
that many people are looking for products, which will offer protection.
Research has shown that correctly fitting anti-thrombosis stockings or DVT socks
increase blood flow, thus lowering the risk of DVT in those at risk.
Advice related to stocking/socks should apply to all forms of travel
when a passenger is sitting still for a long period of time.
- Before buying any products it is essential that
you assess your personal risk factors and obtain advice
from your own doctor regarding fitness to fly, if you are in any
doubt. If you are in a very high-risk category you should seek
advice from your doctor and consider postponing your travel plans.
- There are many different brands on the market
at the moment, each expressing their own unique qualities. It
is important that any DVT stocking/sock purchased be fitted properly
by a professional. A stocking that is too tight and worn by a
traveller with existing circulation problems can do more harm
than good -- cutting into the skin on a long flight and potentially
causing ulceration and increased risk of DVT.
- Never guess the size stocking or sock you require
- ask to be measured properly. A good flight sock will come
in a variety of sizes allowing for measurement from the knee to
the ankle as well as the foot size. If a stocking is too tight
around the knee it will prevent essential venous return causing
the blood to pool around the knee.
- When buying your DVT socks make sure they
are comfortable with your chosen footwear for travelling. Some
flight stockings can be slightly thicker than normal leg covering and
can be potentially restrictive with tight foot wear.
- Do not think that if you wear tight knee-highs
during a flight you will save some money. Any clothing or tight
shoes cutting into the skin around will prevent normal blood flow
and increase the risk of travel related DVT.
- Wear your stockings around the house prior to
travel to ensure you have a good, comfortable fitting. On the
morning of your travel put them on when you get dressed, especially
if you are travelling a distance to the airport. Hurriedly put
on stockings in the airport lounge can cause no end of travel
- Flight socks and stockings are just one-way to help prevent travel
related DVT - take advice from your doctor as well as preventative
advice related to travel.
What can your Health professional do to help?
Your Health professionals will be able to help you
determine your risk factors and provide you with both advice and
written information. They will also be able to guide you as to the
best time to travel after an illness or operation.