Economy class syndrome and blood clots in travelers

“Economy class syndrome” is an old concept that sitting in tight, cramped seats in the back of an airplane can lead to DVTs or blood clots in the legs. The idea of travelers and blood clots/DVTs is an important concept and all travelers need to know about this illness along with how to prevent it. Before we look at a new piece of medical literature on the subject, I think it is important to define a few terms.

DVT = Deep Vein Thrombosis which is basically a blood clot in the larger veins of the legs or pelvis and rarely the arms or torso. Signs of this condition include swelling of the leg compared to the other, a history of immobility and pain in the calf.

PE = Pulmonary Embolism or a blood clot in the lungs. This occurs when the DVT migrates through the veins up to the lungs. This can causes chest pain, shortness of breath and be a life threatening emergency!

Hypercoagulatory state = A condition that makes your blood clot more than normal and some of these conditions include cancer, pregnancy using birth control pills or genetic disorders that change how your blood clots

DVTs and Travelers

The concept of DVTs and travelers began to be linked years ago by noticing travelers on “long-haul” intercontinental flights, who were previously healthy and began developing blood clots. Some of these young and healthy travelers even died from the PEs. Researchers began to link together what they had in common and immobility was the common link. Basically, sitting still for hours and hours caused the blood to pool in the legs and sludge a bit resulting in clots. Although extremely rare the condition is possible and not just limited to airline travel. Minimizing risk is what doctors began to focus on.

Preventing DVTs

Generally, travel medicine doctors have generally avoided the concept of giving “blood thinners” to protect people from DVTs on long flights, car rides, etc. unless they were at very high risk. A good guideline for this comes from the CDC Yellow Book and their chapter on DVT/PE in Travelers. Educating travelers on the importance of in-flight exercises, walking around the plane every few hours and in-chair exercises every few hours has been the mainstay of prevention for most travelers. The CDC article heavily references the wonderful work done by the American College of Chest Physicians and their reports on DVT prevention. The College has recently published a new article specifically aimed at travelers.

 The following conditions are considered risk factors for long distance travelers

  • Previous DVT/PE or known thrombophilic disorder
  • Malignancy
  • Recent surgery or trauma
  • Immobility
  • Advanced age
  • Estrogen use, including oral contraceptives
  • Pregnancy
  • Sitting in a window seat
  • Obesity

Old vs. New Data

What is new about this article is the data now shows there is no increased risk from alcohol intake, flying in economy class versus business class or being dehydrated. These conditions were all previously considered to be risks and things to be avoided by travelers on flights or sitting for greater than 4 hours. In fact, the new guidelines have upgraded a long-haul flight to be 6 hours or longer and most DVT/PE are associated with flights 10 hours or longer. Compression stockings continue to be advised only for patients at high risk and to be avoided for “normal risk” travelers. As expected, stretching and exercises involving the calf muscles are first line for prevention.

Overall, the American College of Chest Physicians continues to lead the world in research and advice on DVT/PE prevention and treatment. This article should be read by all travelers and especially those who travel long-distances!

Flying samaritans crash and clinic suspension

Just received this email about our Tucson chapter of Flying Sam’s service to baja Mexico! Best wishes to the families of the providers who went down providing free medical care to those in baja Mexico!

“Our Chapter suspended clinic related flight operations on November 9, 2010 and canceled the November El Rosario Clinic, thereby honoring the decision of Vic Jones, the President of the International Board of Directors of the Flying Samaritans (the “IBOD”). Mr. Jones’ decision follows the loss of four FS members in a private plane crash near Ensenada, BCN, Mexico on October 15, 2010.”

Read more about the Sams volunteers who crashed here

The Flying Samaritans serve the poorer people of Baja, Mexico who cannot get access to medical care through their privately funded and staffed medical clinics.  Learn more about the Flying Sams and their work at their main website:

Travel medicine video updates from Greece and North Africa

Everything is going quite well from Greece and we are prepping/packing for the upcoming trip to North Africa in 2 days.  We have already been shooting a lot of video on our Adventure Doc Talks video series and hopefully have some usable footage…we will see when we start the editing process.

After a few days in the southern Greek mainland, in the area of Sunio and the port town of Lavrio we started shooting video.  Marine life envenomations were the first topic we started with and we were lucky enough to find some sea urchins and jelly fish very quickly.

After the beaches on the Greek mainland we made our way to the island of  Crete.  On the ferry boat (8 hours) we managed to video sea sickness problems.  The old port of Xania was epic and very amazing…our hotel (Balmondo) was in the perfect location.  We hiked the Samaria gorge and shot our video on lower extremity injuries.  This was the perfect location to hurt your knees and ankles, fortunately none of us did!  We saw some great jellyfish and got some good information on dehydration treatment and prevention.

We are now back in Athens and plowing through a lot of video and completing our transfers onto hard-drive.  Lots of laundry to finish and we are packing for the next leg of the trip…Egypt and North Africa!  We are leaving in a few days and will be working down there for 12 days.  Pyramids, hummus, dehydration, the Nile river and heat stroke are all on the agenda!

Uploading pictures and video, to the web, from this location is difficult so we have to wait until we are back home to share the good stuff!

Travelers, Disease Spread and Responsibility

Cvander photo

The world is a big place and most travelers want to see it all.  The double edged sword of travel is that by going to that unique place, you are contaminating it with your culture, ideas and mere presence.  Having a great time somewhere makes you want to go back and tell your friends.  This means more people will be there, when you re-visit.  The “original” place will have adapted to the influx of travelers.  Thus, you’ve helped ruin your own favorite place.

Responsible Travel

There is the concept of “responsible travel”, although I have yet to hear a good definition.  This, to me, is lessening the impact of travel and tourism on a location and local people.  Responsible travel can mean not staying in a hotel that was made by clear cutting rain forest and using services that protect the environment.  I am all for this concept and applaud those who practice it!  I would like to submit another item to the list of “responsible travel”…reduction of disease spread.

Debarka Banik photoInternational travel has increased from 25 million in 1950 to 898 million in 2007.  2% of the world population (more than 200 million) lives outside their country of birth.  Specific reasons for travel also show interesting statistics.  Business travel, VFR (visit friends/relatives), pilgrimage and health care are increasing reasons for crossing borders.

Obviously, as travel methods improve, more people travel.  Larger and faster methods of travel, think jets and boats, now carry more people.  Studies have shown that the risk for a travel acquired infection increases four times, when the aircraft size doubles.  Larger ships carry more ballast water over long distances, transporting water-borne bacteria to new ecosystems.

Photo Mr. ThomasCruise ships are increasing in popularity, with 11.5 million travelers in 2005.  In the past, cruise ships have served as excellent sources of  infection transportation, as well  as source outbreaks.  For more information on cruise ship specific health, visit here.

Recent examples of disease spread has clearly made use of the international traveler as a method of carrying disease.  Legionella outbreaks on cruise ships, Dengue in Hawaii, Meningitis and the Hajj, SARS and Hong Kong, Tuberculosis and the list goes on.  But this idea of travelers spreading diseases is not new, by any means.

Measles is a very old illness and one of the best examples of travelers carrying disease.  As European explorers traveled to the New World, they also brought measles and small pox.  This decimated local people and expedited the collapse of their civilization.  Attempts at measles eradication are working, as is the ability to better track cases and outbreaks.  This ability allows for comparison of different strains and following effects, globally.  For example, in 2008 a Swiss visitor was hospitalized in Arizona for measles.  The traveler acquired the infection in their home country and subsequently infected nine other people through their voyage. 

Photo AugapfelResponsible travel means not harming the place you are going to.  Carrying disease from one place to another can harm others.  One thing I keep reminding myself is that travel is not “point A to point B”.  There is a return trip in there, eventually.  Nobody wants to bring an infection back with them and spread it around town.  If everybody you have been showing your Safari pics to is sick with a rare African virus a few days later, you will have some angry friends.

Practicing Responsible Travel Health

  • The first way travelers can begin practicing responsible travel health is to realize that they are capable of carrying illness to any of their destinations, including back home. 
  • Second should be basic precautions to prevent disease spread, not only for your sake, but others.  This is hand washing and knowing their immunization status. 
  • Third, research your destination (s) and plan ahead for any potential health issues. 
  • Lastly, take a hard look at immunizations and medicines you might need for your trip.  This often involves a re-check of your childhood vaccines, as well.

Vaccine Preventable Infections 

Several infectious diseases are vaccine preventable.  A traveler who is at risk for contracting these “preventable” illnesses can also carry that disease around the world, infecting many others.  By having the traveler properly immunized, the traveler never gets the infection and cannot carry it to others.  Prime examples of these vaccine preventable diseases include Hepatitis A, Influenza, Measles, Mumps and Polio.  These are “childhood immunizations” commonly given in industrialized nations.

Putting it Together

Travelers are some of the most effective ways to share and communicate new ideas, cultures, opinions and understanding.  As a traveler, you are becoming a participant in Global Health, like it or not.  The responsible thing to do is ensure that you are not traveling the world as “typhoid mary“, spreading illness as you go.  This, to me, is responsible travel.

Winter Car Travel

As the temperatures start dropping and I am getting ready for the “white stuff” to hit the ground, we are starting to plan out holidays.  Most people I know are looking forward to getting together with their family, whom they may not see too often, and will be driving to the gatherings.

Having a “winter travel car kit” that you can put in the back seat or trunk is important and here are some things that you may want to include, and why:

  • Extra jacket, pants, gloves and hat to keep you warm

Keeping warm, especially if you are having to sit out a blizzard is vital.  Remember that you will be sitting in a car and moving to help generate body heat is vital.  Extra layers can not only add some comfort, but also save a life.

  • Several long burning candles

Candles can help generate heat in the car, provide some light and help you melt snow for drinking water

  •  Matches

Lighters may not work in very cold environments. 

  • Headlamp or flashlight with spare batteries

Unfortunately, you may have to sit out bad weather or wait for help overnight.  A light can do wonders to help signal others, boost morale and assist in finding items in your vehicle.  I am a fan of petzl headlamps.

  • Food such as jerky, hard candy, chocolate, nuts and raisins

Extra calories help you stay warm and a little “comfort food” can go along way

  • A metal cup

Any flame-proof object can be filled with snow and, using your candle, drinking water can be melted.  A metal cup is best because it transfers heat from your candle to the snow inside, faster.  To avoid dehydration, remember to drink before you are thirsty.  All that snow trapping you in your car can at least help you stay hydrated!

  • Mobile phone with charger

Call for help and communicate with others about your position, direction of travel, type/make of car, number of people with you and their condition.  Ideally, a portable battery type charger will keep you from needing to run the car engine and charge your phone.

  • Self-powered radio with weather channels

Get up to date information on road conditions, weather status and something to help pass the time.  The Red Cross has a very nice product that features phone charger, light and several power options.

  • 50 feet of cord

This can be used to tie a “umbilical cord” between you and your vehicle if you have to leave the vehicle.  During a severe “white out” condition, even trying to get from your seat to the trunk and back can be difficult.  Tying a line will allow you to safely reach you vehicle if you have to go outside.  I like to use spectra cord for this purpose.

  • Whistle

Signal for help, alert others to your presence

  • Carbon monoxide detector

There is some danger that keeping your car running helps carbon monoxide build up in the passenger areas, and CO poisoning can kill.  This is not a problem when you are moving, because there is generally adequate ventilation of the inside.  However, a car that is not moving and receiving heavy enough snowfall to block the tail-pipe is at risk for CO poisoning.  Some suggest running your car at intervals (running 5 minutes every 15-20 minutes) to help keep passengers warm.  Still, one should attempt to clear the tail-pipe from snow or debris, allowing better ventilation of the CO gas.  If you do have to leave the car to dig your exhaust pipe out, make sure to use your cord as a tie off around your waist and the vehicle. 

  • Two large plastic garbage bags

Unfortunately, you may need to use the bathroom during your wait and there are about a million uses for garbage bags, including emergency rain jacket

  • Sleeping bag

Help keep everybody warm and cozy

  • Toilet tissue

Can be used as intended, for bathroom breaks, also makes a great fire starter

  • Leatherman multi-tool or swiss knife

Everybody who goes anywhere should carry one of these.

  • Basic first aid kit

An assortment of bandages, pain/fever control such as tylenol, antihistamine, etc.

  • Three days supply of personal medications

If you take medication on a regular basis, you need to have an small supply to last you while you are waiting for the weather to clear and help to arrive.

  • Surveyor’s tape

This can be tied to your antennae, hung out a window or wrapped around anything you want people to notice, especially in bad weather.  Here’s what it looks like and it can be found at most home repair stores.

  • Signal flares

Place these around your care, to help others see your car.  This can help in getting rescuers to see you need help and help other motorists from driving into your stopped vehicle.

There are many web-based resources to learn more about safe car travel, during winter months and especially in bad weather conditions.  Here are a few I liked:

Road Accidents and Travel

When I think of an adventure trip, such as a week climbing, kayaking or mountain biking, I try to be prepared for all the problems that I might encounter.  A careful pre-check of my gear, a first aid kit and plan of what to do if something bad happens are all ways I decrease my risks, during my outdoor activities.  Wearing a seat belt and making sure I drive safely to my destination are some other things that help reduce one of the biggest risks to international and adventure travelers.

International Travelers often face a hidden risk that is not often though of, when they travel by road. Road Traffic Injuries are the leading cause of injury related deaths, worldwide. According to the US State Department, road traffic crashes are the leading cause of injury death in American Citizens when traveling internationally. Many travelers take steps to ensure a safe trip by preparing with vaccines, a health kit and some knowledge about their destination. Unfortunately, little though is given to safely traveling from one potentially risky and exciting event, to another.

A wonderful page at the CDC Yellow Book, about injury prevention, discusses tips for safe surface travel, internationally. Most of it seems to be common sense, but I admit that I am not always thinking about these things, when I am traveling.

  • Use safety belts and child safety seats when traveling.  These simple measures save lives.
  • Try to rent a larger vehicle for increased protection
  • Ride only in licensed and marked taxis and sit in the rear seat.  Consider offering the driver a tip if they drive in a manner you feel safe with.
  • Look both ways when you cross a street, anytime, anywhere
  • Wear a helmet when riding a motorcycle, all the time
  • Don’t drink and drive.
  • Avoid driving at night, especially in unfamiliar areas
  • Check websites such as Association for Safe International Road Travel(ASIRT) for road conditions

The NaTHNaC (National Travel Health Network and Centre)also has a very good article about car crashes and the international traveler.  Hopefully, there will be a brief moment, when you are about to travel by road, when you think about your safety.  Nobody wants a car crash to ruin their trip, or worse.

Sea and Motion Sickness

Image IlectrologosI have survived the majority of my time in Greece.  I also learned a lot and realized how little I do know.  Overall, an amazing experience and I have a lot of new topics to discuss!  A common problem I saw was motion or seasickness.  Ferry boats are very common inter-island travel and a source of a lot of problems for those who suffer from this “trip ruining” condition.

If you are one fo the unlucky people who get car, boat or air sick…there are some things you can do to help minimize the discomfort. First, one should realize the problem is not in the stomach, at all. The issue is primarily a confusion of signals being sent from the eyes, inner ear and the brain. Even though your stomach seems to be the effected spot, the problem is literally in your head.

Image JimG944One of the few studies done on sea-sickness was mentioned in the Travel and Tropical Medicine Manual. This study looked at travelers in the English Channel and Irish Sea. Involving more than 20,000 participants, the study concluded several important things:

  • Women are more likely to get seasick than men
  • The older you are, the less likely you are to suffer from seasickness
  • Nearly one-third of passengers reports feeling motions sickness symptoms including nausea, cold-sweats and weakness.


So now we know who is likely to get it, how common it is and what it feels like. How to prevent it? First, where you sit and what you focus your eyes on play a large part in basic prevention and help decrease the symptoms. Finding a comfortable seat with a smooth ride is, perhaps, most important. Avoid reading or focusing your eyes on near objects. This is because the nearer the object, the more exaggerated the movement is noticed by your brain. Try to focus on the horizon or a distant object, which will be moving less than the closer objects. Closing your eyes may also help. One interesting article looked at location of cruise ship cabins and found no association with feelings of seasickness. The study did confirm age and sex relationships.


For those that may require a bit more help that closing your eyes, there are several medications commonly used. One is scopolamine and the other type are anti-histamines. Scopolamine is famously know as the “patch” that is apparently a common fashion accessory on a cruise ship. Anti-histamines such as Benadryl and meclizine (Antivert) are also alternatives to scopolamine.

Alternative Treatments

Image tomeppyAnother option that is actually a very old method is the use of pressure bracelets or pressure bands. These use the premise of chinese accupressure and apply gentle pressure to the P6 Neiguan pressure point. Several studies have shown anti-emetic effects in pregnancy induced nausea and during medical procedures. There are no decent studies, I know of, that look at sea sickness, specifically. A few natural remedies include ginger and there are actually some interesting articles about this as an anti-emetic for pregnancy and chemotherapy.

Seasickness is something I have never experienced but I have seen it ruin many people’s trips. Most I know who have this problem actually begin to worry about the trip, days before the boat is boarded. Hopefully, this will give people a few options to combat that nasty feeling. For some more info try: CDC Yellow Book: Motion Sickness