Economy class syndrome
Many people who often take long-distance airplanes or long-distance train hard seats have experience, a dozen or twenty hours of travel down some people not only numb feet, and even swollen feet even shoes can not wear. This situation in our medical has a very image of the name, called “economy class syndrome.
Economy class syndrome refers to blood clotting in the deep veins of the pelvis and lower extremities during or shortly after a long plane trip due to sedentary reasons, namely deep vein thrombosis. Airplane travel itself does not significantly increase the risk of DVT formation; meditation is the culprit. The lack of movement slows down the blood flow, especially in economy class where the seats are narrow and compact, limiting people’s activities, plus many people take the bus and drink less water on purpose, making the blood thicker and more prone to thrombosis.
Why sitting still causes blood clots
There are two sets of venous system in human, usually we can see the “veins” that is the superficial veins, while the deep veins are covered by muscles. When it comes to muscle, it has something to do with “movement”, the contraction of muscle is closely related to the flow of blood in the veins. There are many diaphragms in the veins that open only toward the heart, called venous valves, these diaphragms are like doors, for closed doors, pushing from the outside to the inside will make the door open, people can enter the house, and then pushing from the inside to the outside, it will close; the venous blood flow in the lower extremities is like this, when the muscle contracts, it compresses the vein and makes the blood flow, for the valves above this section of the vein, the blood flow is like the hand that opens the door and rushes the valves to the heart. For the valves below, the blood flow is like the hand that closes the valves, preventing the blood from returning downward due to gravity. At the same time, during exercise, muscle contraction requires more blood and blood flow increases, so that the blood flow in the veins is accelerated. As “flowing water does not rot”, the flow of blood is not easy to clot.
If our lower limbs do not exercise for a long time, there is no muscle contraction pressure to open the venous valve, blood will be stagnant in the blood vessels can not flow smoothly, and gradually coagulate to form a thrombus. And fixed sitting position more than three hours, the risk of thrombosis will be greatly increased than normal people.
Serious consequences of deep vein thrombosis
Although the thrombus in the deep vein will obstruct the blood return, resulting in blood pooling in the lower extremities, manifesting as pain, swelling, redness, increased skin temperature, and obvious exposure of superficial veins or even varicose veins, as many as half of the patients may not experience any discomfort. Pulmonary embolism is a very dangerous disease that can lead to sudden death in severe cases, and is the third leading cause of death in the United States.
Brain death: As we all know the main function of the lungs is to provide oxygen to the whole body and expel carbon dioxide, if the blood flow of the pulmonary artery is blocked because of thrombus, it will lead to lack of oxygen to the whole body. Especially brain tissues, because the brain is relatively more sensitive to the need of oxygen, but the ability to tolerate hypoxia is poor, so a brief lack of oxygen can lead to syncope, and five minutes of hypoxia, even if other organs can continue to work with the help of medical instruments, the damage to the brain is generally considered to be serious and irreversible, which is brain death.
Impaired heart function: Also when there is a blood clot in the pulmonary artery, just like when there is something behind the door, then to open the door you have to push the door harder, and the right ventricle contraction is relatively weak, if you can’t maintain enough blood pumping from the right ventricle, the circulation is interrupted, leading to systemic ischemia; when the right ventricle is contracting at full strength, it will itself be “overworked When the right ventricle is fully contracted, it will itself be damaged by “overwork”, leading to acute heart failure and arrhythmia, both of which can lead to impairment or loss of the heart’s function of driving blood flow, manifesting as chest tightness, palpitations, syncope and even sudden death.
Pulmonary infarction: If the thrombus is large and completely blocks pulmonary artery blood flow to part of the lung tissue, it can lead to severe local ischemia, and this part of the lung can die, leading to pulmonary infarction like the familiar myocardial infarction due to coronary artery occlusion.
However, in order for the narrowed tube to pass the same amount of fluid, the flow rate has to be increased, and the pressure difference between the two ends has to be increased, so the pulmonary artery blood pressure has to be increased, leading to pulmonary hypertension, and in order to maintain this pressure, the workload of the right ventricle increases, which can lead to right ventricular dysfunction.
Who is prone to deep vein thrombosis
It has been found that people with prolonged sitting or lying down, old age, obesity, recent pregnancy or postpartum, serious diseases such as dehydration, heart failure, other diseases, genetic abnormalities or medications such as birth control pills that cause abnormalities in some components of the blood leading to reduced ability to dissolve blood clots, people who have had deep vein thrombosis due to infection, trauma, surgery, old blood clots, certain autoimmune diseases that cause damage to the innermost lining of blood vessels, and people who have had deep vein thrombosis. Although there are many causes, each of them does not significantly increase the risk of getting the disease, which makes it difficult to prevent the disease.
For example, some young people who are addicted to computer games or the Internet have reported sudden death due to pulmonary embolism after sitting still for long periods of time.
Another situation should be mentioned in particular, some patients have deep vein thrombosis on the left side because the right common iliac artery compresses the left common iliac vein, and the venous blood flow of the left foot has to pass through the left common iliac vein. It is called “left iliac vein compression syndrome”.
How to prevent deep vein thrombosis
The three main culprits of intravascular thrombosis are: blood hypercoagulation, slow blood flow, and intimal damage.
Therefore, for us, the easiest way is not to sit or lie still for a long time, but to exercise more to speed up blood circulation.
Inpatients, even just after surgery, are encouraged to get out of bed more often, which not only prevents DVT, but also facilitates the recovery of cardiopulmonary function, increases gastrointestinal motility, and reduces the occurrence of pneumonia and constipation.
Detection and treatment of deep vein thrombosis
First of all, we should be vigilant and seek timely medical attention after finding unexplained lower limb swelling, pain and varicose veins. If deep vein thrombosis can be detected early and treated early, the serious consequence of pulmonary embolism can be avoided. In our experience, the most common symptom is swelling of the lower extremities, and the first department is usually internal medicine or emergency medicine, because it can be caused by heart, kidney, and lower extremity infection.
By analyzing the medical history and the results of the examination, if deep vein thrombosis is suspected, blood may be drawn for D-dimer, and color ultrasound and CT of the blood vessels of the lower extremities will be done. After the diagnosis is confirmed, the next treatment is mainly in three aspects.
1, drug injection to stop the thrombus from continuing to increase in size or even dissolve the thrombus already produced.
2.Preventing the thrombus from dislodging into the pulmonary artery, either by implanting a temporary or permanent inferior vena cava filter.
3, to prevent future recurrence of thrombosis, that is, to continue to take the oral anticoagulant Favarine for a period of time or even for life after discharge from the hospital.
Pulmonary thrombosis is scary, yet preventing it is simple and effective. For urban humans who are sedentary for long periods of time, all we need to do is to move more and drink more water. So the next time you sit for two hours straight, remember to get up and take a few steps and stir your legs to keep your deep veins open.