One of the biggest concerns about a long flight, apart from boredom, a screaming baby in the seat behind you and a meal that tastes like yesterday, is the fear of the health damage that can be caused by long flights.
The most famous of them is the fear of the formation of a blood clot, which can create a situation where the clot breaks off and drifts towards the lungs, which can cause serious health problems and even, in extreme cases, death.
When it comes to people with a high risk or a history of clot formation, the fear is understandable, but in many cases it is also normal people who do not have an increased risk of clots anymore, or who are heterozygous mutation carriers (a condition in which only one gene carries the mutation), who fear before long flights.
The web is full of contradictory, misleading and even incorrect information, and the initial recommendation is of course to consult the family doctor regarding the health condition and if any treatment is necessary before a long flight.
Many doctors advise non-high-risk patients to inject Claxan before the flight, a drug that causes blood thinning, but is it really necessary?
We checked.
Don't sit still too long.
Passengers on a flight (those photographed have no relation to the article), photo: Moshe Shay
"Let's start by breaking the myth," declares Dr. Anat Rabinovitch, director of the Blood Coagulation Unit, Hematology Institute, Soroka University Medical Center. "There is a risk of a deep blood clot in the deep veins of the legs or its complication, a pulmonary embolism.
The risk increases on a flight that lasts more than 4 hours, and even when you get off the flight the risk still remains high for the first two weeks after it.
But in how many cases does a blood clot actually form?
The numbers are very low.
In other words, less than 0.05% of people who board a flight will develop a significant venous coagulation event."
Who is more likely to get a clot?
"Most people in this group are those who have risk factors. It is very rare for other people to develop a blood clot in flight. Risk groups include those who have had a previous venous thromboembolic event or those who have active malignancy (cancer), malignancy of the pancreas or stomach, lungs, or Under chemotherapy treatments, pregnant women mainly in the third semester, people over 80 years old, people with significant obesity - BMI over 35, women who use the pill or hormone replacement therapy, those who have undergone surgery - including hip or knee replacement - in the first six weeks after surgery. But you have to understand that each of these risks is different. Those who only take a pill increase the risk a little, and to develop the event you need a combination of several factors, not just one, and of course - within all of this the matter of genetic or acquired hypercoagulability also comes into play."
So what are the mutations related to this?
"Factor 5 (Leiden), and the factor 2 mutation, are the most common mutations in the population, but there are other types of acquired hypercoagulability that are more dangerous than these mutations - between 10 and 20 percent are carriers of the factor 5 mutation, and between 5-10 percent are carriers of the factor 2 mutation, but most people will not express any coagulation event in their lifetime - the risk of developing a coagulation event in carriers of factor 5 Leiden or prothrombin is 5-10 percent during the entire lifetime (lifetime risk). There are entire families in which the mutation is inherited, and no one Family members don't pronounce it."
When is there a higher risk for carriers?
"If a first-degree relative expressed the mutation - he had a coagulopathy event, in such a situation there is more risk that the person himself will also develop a coagulopathy event. A second situation is that the mutation may manifest itself in a coagulopathy event - when added to the genetic basis of the person there is also an external stimulus, a combined pill to prevent A pregnancy that contains estrogen, the pregnant woman, after surgery, had a trauma, and even on a flight the risk may increase. But of all these things, the flight is the risk factor that increases relatively low."
It is important to check if you are at increased risk.
Flight (illustration), photo: Getty Images
As mentioned, the recommendations are different and varied, but there are some rules that the general population and people with increased risk in particular should follow during a flight.
"There are recommendations from the American and British Association of Hematology - and for most flights there is no recommendation for giving prophylactic anticoagulants," explains Dr. Rabinovitch, "there are recommendations for general precautions, such as getting up from the chair and walking on the plane once every two hours, moving the legs, bending and straightening of the foot and ankle joint and bending and straightening the knee, and there are things that have not been studied but are considered precautionary measures, such as drinking lots of water and reducing alcohol consumption.
"Another measure recommended for people in risk groups only is compression socks in flight, but not all compression socks sold in every store are for flying. The recommended compression socks are up to the knee, with a rated pressure of 15-30 mm Hg in the ankle.
These are socks that have been researched and shown to reduce the risk of venous hypertension on a flight."
What about the recommended shot, Claxan?
"It is not recommended for the entire population and not blindly. It is given on a case-by-case basis, each case is examined individually and is given only to those who are assessed to be at a particularly high risk of developing a coagulopathy on a flight, and that the benefit of giving an anticoagulant outweighs the risk - or that the person is in a special risk group, from those we mentioned , when there is a combination of several risk factors, or when there is someone with hypercoagulability that we perceive as high risk. In this situation, when there is a recommendation from the hematologist to receive prophylactic antidote on the flight, one injection of Claxan is given in different doses that depend on weight, one injection before the outbound flight and one injection before the flight return".
And what about the side effects?
Flight (illustration), photo: Getty Images
What about those who are already treated with anticoagulants regularly?
"They should continue to take blood thinners on the flight as usual, and there is no need for the addition of a drug or an injection. Research-wise, the only product that has been tested is Claxan, and all other oral treatments such as aspirin, coumadin, and more - have only been tested when they are given long-term when there is a need for long-term administration, and there is no Studies that tested the effectiveness of the drugs when they are given in a single dose to cover a short term."
Does the injection have side effects?
"It thins the blood, so there is a risk of bleeding. With a one-time administration of a blood thinner in a small prophylactic dose, the risk is not high - but the risk of developing a coagulopathy is not high either."
How do you recognize if clotting develops during a flight?
"The common condition is called DVT, a blood clot in the deep veins of the leg, which can be manifested by pain in the leg, swelling, redness, these are the signs. It can also appear up to two or three weeks after the flight. When a clot breaks off and is carried to the lungs, a pulmonary embolism is formed that causes shortness of breath, a cough that can having blood, chest pains and fainting."
In conclusion - it is always recommended to consult a hematologist if you are in a risk group, and not to be automatically alarmed by any advertisement you see regarding the risk of developing a blood clot on flights.
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