Deep Venous Thrombosis
Deep Venous Thrombosis (DVT)
Deep Venous Thrombosis (DVT) has been called ‘Economy Class Syndrome’ by the media. This, of course, refers to the possible connection between the risk of developing DVT and the relatively confined space available to the passengers in economy class seating. DVT is not restricted to passengers in economy class. It also occurs in passengers in Business Class and First Class. In fact, DVT can occur in any situation where a person is sitting still for a long time. This could be in the home, at work, on the bus and of course, in an aeroplane.
Under normal circumstances, blood is pushed back from the legs to the heart with the help of what is called the muscle pump action, i.e., when we use the muscles in the legs, these veins contract and push the blood from the legs back up to the heart. Valves in the veins make sure that the blood cannot run backwards.
DVT occurs particularly in situations when the blood is pumped back from the legs too slowly, or when it stops completely. This may be due to sitting completely still without moving the legs. DVT can also occur if there are defects in the valves in the veins, allowing the blood to flow backwards. If the blood is thicker than normal, because of dehydration (lack of fluid) for example, the risk of developing DVT increases. Pregnant women and women on birth control pills have an increased risk of developing DVT.
It is therefore of great importance that passengers constantly use the muscles in the legs by moving toes and feet during the flight, and if possible go for regular, small walks.
Dehydration
The air temperature outside the plane is generally -54 C. This air is then taken into the plane and warmed up. Since cold air does not contain much moisture, the humidity level in the cabin is very low, with most of the humidity coming from the passengers themselves (evaporation and exhaled air).
Cabin humidity is generally around three to five percent, compared with the normal 60% or so in temperate latitudes. Since coffee, tea and, in particular, alcohol have a dehydrating effect, the body may start to suffer from a lack of fluid. Passengers can help prevent dehydration by drinking plenty of water before and during the flight.
Support Hose (support stockings)
It is now possible to buy “medical” support hose/compression hose of a very high quality and which look like normal tights. They are available in several colours, including black for men. These supports hose squeeze the leg, mainly at the ankle and then decreasing up the calf, so that there is a graduate level of pressure is exerted on the veins. The blood is thus pushed in the right direction, towards the heart. Passengers with an increased risk of developing DVT are advised to use such support stockings during flight.
Junior Aspirin
Unless Individuals have known allergies, a low dose of Acetylsalicylic acid (i.e. Junior Aspirin) is recommended on the day of departure. This will reduce the propensity of the blood to clot (same mechanism as when aspirin is used for prevention of thrombosis).
If you are on regular medication, always bring this on board in your hand luggage. When travelling alone, you should inform the cabin crew about this when boarding.
If in doubt about possible health risks if travelling by air, passengers are always advised to consult their General Practitioner for assessment and advice.