It is important that arterial and venous system should work properly without causing the problem to blood circulation around the body. Pureblood flows from the hearts to legs through arteries taking oxygen and food to the muscles, skin and other tissues. Blood then flows back to heart carrying away waste products through veins.
The valves in veins are unidirectional which means that they allow the venous blood to flow in an upward direction only. If the valves do not work properly or if there is not enough pressure in veins to push back the venous blood towards the heart, this will lead to pooling of blood in veins and this leads to higher pressure on the skin. Because of high pressure and lack of availability of oxygen and food, the skin deteriorates and eventually, ulcer occurs .
The Causes Of Venous Leg Ulcer
- The inefficient or non-function of valves in veins.
- Inefficient or non-functioning of calf muscles.
- Pooling of various blood in veins.
- Damaged or swollen veins (varicose vein).
- Blood clots in veins (DU thrombosis).
- Lack of movement (traveling, flight).
Venous Leg Ulcer Treatment
Venous leg ulcers are chronic and there is no medication or surgery to cure the disease other than compression therapy. A partial increase in compression improves the flow of blood back to the heart, which improves the functioning of valves and calf muscle pumps, reducing oedema and prevents swelling of veins. Mostly old people are prone to develop DVT, varicose vein and venous leg ulcer. This ulcer is of frequently occurring type.
Compression bandages are mainly used for the treatment of venous leg ulcers and varicose veins. The aim of use of various compression bandaging is the reduction of venous hypertension which results from valve ulcer insufficiently. The application of external compression by means of bandages serves to increase the velocity of blood flow within the vein by providing support to the muscles. It has been seen that venous return is faster and more efficient if the compression bandage is applied in a manner that gives sub-bandage pressure that is graduated from ankle to the knee (greater at the ankle than at the knee). Elastomeric bandages made with rubber were first used in the 19th century and this has now been replaced by lycra which is light, strong, comfortable and washable. This is woven, knitted and designed to give required pressure.
Classification Of Compression Bandages
Compression bandages are mainly classified as elastic and non-elastic. Elastic compression bandages are further classified depending on pressure generated on the ankle of an average leg. Compressive stocking provides support to treat DVT and venous vein and to prevent venous leg ulcer .
- Class 1 light support.
- Class 2 medium support.
- Class 3 strong support.
Further, they are classified as
- Class 3a bandage gives high compression of 14-17mm Hg.
- Class 3b bandage gives moderate compression of 18-24 mm Hg.
- Class 3c bandage gives high compression of 25-35 mm Hg.
- Class 3d bandage gives extra high compression of up to 60mm Hg.
This extra high compression bandage is not often used because the very high pressure generated will reduce the blood supply to the skin.30-40 mm Hg of pressure at the ankle which is reduced to 15-20 mm Hg at calf is adequate for the healing of venous leg ulcers.
Ideal Compression Bandages
Compression bandages are harmful if not applied properly. Compression bandages provide high tension as well as high pressure. So following factors should be considered before applying bandage on limb 
- The magnitude of pressure.
- Distribution of pressure.
- Duration of pressure.
- Limb radius.
- A number of layers.
The ability of a bandage to provide compression is determined by construction and tensile forces generated by the elastomeric fibre when extended.
This pressure or compression can be calculated using Laplace’s law.
Where P = pressure Exerted on limb by application of compression Bandage
T = Tension Exerted compression Bandage
r = Limb radius
Laplace’s law states that “Pressure is directly proportional to the bandage tension during application and number of layers applied but inversely proportional to limb radius”.
The structure of compression bandage is therefore regarded as an important factor in providing uniform pressure distribution.
Properties Required From Ideal Compression Bandages
When any type of bandages are used to cure the venous leg ulcer it may be elastic or non-elastic compression bandages but it should possess following properties .
- It must give proper compression for the individual.
- It must distribute pressure evenly over anatomical leg contour.
- It must provide reducing pressure from ankle to calf.
- It must maintain the pressure for a long time.
- It must remain in position till next change of dressing.
- It must function in a complementary way with the dressing.
- It should have non-irritant properties.
- It should have non-allergenic.
Compression can be exerted to the leg either by single layer bandage or multilayer bandages. In the UK 4 layer bandage is used while in Australia non-elastic 2 layer bandage is used. A typical four-layer compression bandage system consists of padding bandage, crepe bandage, high compression bandage, and cohesive bandage. Both the two layer and four layer system requires padding bandage that is applied next to the skin and below short stretch or compressive bandage. A plaster type non-elastic bandage called ‘Unna boot’ is used in the USA. It is found that ‘Unna boot’ is rigid, is uncomfortable to wear and also monitoring of ulcer after boot is applied is impossible.
Padding bandage is very important part of a compression bandage.A variety of padding bandages is used beneath the compression bandage as padding layers, in order to evenly distribute the pressure and give protection. They absorb high pressure created at the tibia and fibula regions. It will be noticed that structure of padding bandage is an important factor in producing uniform pressure distribution. 
The properties required from padding bandages are
- Lightweight and easy to handle.
- Soft and impart cushioning effect to the limb.
- Capable of preventing tissue damage.
- It should distribute pressure evenly.
- Good absorption and wicking properties.
- It should be non-irritating.
- It should be non-allergic.
- It should be.
- It should be cheap.
- It should be easily torn by hand.
In order to provide and to maintain adequate compression, it is essential that bandage remains firmly and securely in place on the leg. There are two bandaging techniques which have been used with good results in healing of various leg ulcers. 
- Combine bandaging technique/ simple spiral technique.
- St Charles bandaging technique.
Bandaging material required is
- Orthopedics wool/padding
- 5 pieces of tape 5 cm wide and 50 cm long
- Compression bandage 10cm wide 5 m long
In spiral technique bandage is rolled spirally in an even pattern up the leg from base of toe to knee and in combined technique, about mid-calf the spiral is sharply brought up to just below the knee and full turn is made and then the bandage is rolled down spirally covering the rest of the leg. In St. Charles technique bandage is secured from the base of the toe to just below the knee. It is useful to all types of legs. This method suits the patients who are mobile.
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