What exactly is economy class syndrome, and what can do to avoid getting it?
There has been a lot of press about air travelers confined in tiny economy class seats on very long flights who wind up developing pulmonary emboli. A recent article estimated that economy class syndrome occurrs 30,000 times world wide in an average year, and that many people have died from their emboli. The problem is certainly going to become more common as more planes travel very long distances without refueling, making non-stop flights of 10-to-12 hours routine.
Pulmonary emboli are caused by blood clots that form in the veins, usually the deep veins of the legs, but occasionally veins in the pelvis. These clots then break loose and travel through the veins to the heart, where they are pumped out to the lungs. Small emboli are rarely noticed, although if they occur in large numbers they can cause problems. Medium-sized emboli will block a branch of the pulmonary artery, and cut off the blood supply to a segment of the lung. This may cause the death of some lung tissue, termed a pulmonary infarct, and although this may be painful, it is rarely fatal. Large emboli can block all the blood flow to both lungs and are rapidly fatal.
Over the years, we have learned more about the formation of such emboli, and forced inactivity in a sitting position is one of them. It’s unfortunately all too common in economy class with the crowded seats, narrow aisles, and limited opportunities to move about. It’s also significant that we don’t hear about this problem occurring in business or first class seats, where passengers legs can be raised higher, and the wider aisles allow people to stretch.
There are a number of factors that will increase the risk of this happening on a long flight:
- An increase in the tendency of the blood to clot, a condition called hypercoagulability, can be seen in people who have genetic conditions called protein C or protein S deficiencies. Other conditions including some cancers can also lead to a hypercoagulable state.
- Orthopedic surgery, especially on the hips or legs can increase the risk of thrombosis for several months. Chest, abdominal and bladder surgery can also do so, although less frequently.
- Pregnancy, and the use of estrogens either in birth control pills or as hormone replacement can lead to increased coagulability.
- A history of a previous deep vein thrombosis is also a risk factor.
- Personal factors that can play a role in the formation of deep vein thrombosis include: being very overweight, wearing constrictive clothing that squeezes the upper thighs, and drinking alcohol. Liquor tends to lead to dehydration, which in turn increases the coagulability of the blood.
- Varicose veins, which are very common enlargements of the surface veins of the legs, are rarely the source of pulmonary emboli. One can form clots in varicose veins, a condition called thrombophlebitis, meaning inflammation of a vein with thrombosis, but these rarely give rise to pulmonary emboli.
Since most of us never get tested to see if we have Protein C or S deficiency, don’t often fly after serious orthopedic or other surgeries, and have never had a previous deep vein thrombosis we don’t really know if we are at increased risk.
There are two important things we can we do to protect ourselves from this possibly fatal condition during long flights:
- Prevent stasis, the pooling of blood in the legs because of inactivity, or constricting clothing. To prevent stasis, don’t wear constricting clothing, and move the legs regularly, preferably by getting up and walking in the aisles for a couple of minutes. Nobody wants to annoy the people sitting between them and the aisle by getting up frequently, but consider that you are actually doing them a favor by forcing them to stand and move into the aisle, thereby preventing stasis in their legs. If you absolutely can’t get up and out of your seat, make a point of alternately contracting and relaxing the muscles in both your lower and upper legs for a couple of minutes every hour. This duplicates the pumping action on the veins which we use when we walk. Elastic stockings which constrict the lower legs are also helpful in preventing stasis. Many people already wear them to control varicose veins, and they will help prevent deep vein stasis as well.
- Decrease the coagulability of the blood. Drink lots of fluids to prevent dehydration, and watch the alcohol. Fluids will also force you up and out of your seat to the toilet frequently thus reducing stasis. People who are not taking regular aspirin should consider taking one regular aspirin per day for the week before they are going to fly, and I would certainly suggest this tactic for women taking birth control pills or estrogen to reduce the increased coagulability that these drugs confer. Acetaminophen (Tylenol) will not reduce coagulability. You must use good old aspirin, unless you have some contraindication to taking it.
Of course it’s best if you can combine: aspirin, pushing fluids and walking frequently to prevent stasis. Doing as many of these as possible will provide the best protection against deep vein thrombosis during long plane flights.