First aid should aim to support the measures taken by the body itself to control the bleeding.
In the case of capillary bleeding, the body is generally capable of controlling bleeding without assistance, and first aid should consist of cleaning and dressing the wound.
In controlling arterial and venous bleeding, the body can be assisted with three measures: compression, elevation and rest.
Compression
In the case of arterial and venous bleeding, the most effective method to keep the blood in the circulatory system and to optimise conditions for blood clot formation is to close the damaged blood vessel through compression. This pressure can be exerted using a finger or fist, but a well-applied compression bandage is also effective.
For moderate venous bleeding, light pressure exerted on the skin, at a site distal to the wound, is often sufficient.
In the case of bleeding from an artery, it is more effective to block the blood supply to the wound by pressing down on the artery with your fingers. This form of compression, which can also be achieved with a compression bandage, should not be used for all forms of arterial bleeding as the pressure point must fulfil four requirements.
- The pressure point must be located between the heart and the wound.
- The ruptured artery must be a branch of the artery which is being compressed.
- At the pressure point, the artery must be directly below the surface.
- It must be possible to compress the artery by pushing it against a hard underlying surface (bone tissue).
Elevation
By raising the injured part of the body above the level of the heart, a hydrostatic pressure difference is achieved which slows the blood supply. Bleeding should decrease and the pressure on the blood clot will be reduced.
Rest
By avoiding unnecessary muscle activity, an increase in oxygen requirement is avoided. As a result, there is no need for an increase in the blood supply and the associated vascular dilatation in the affected body part is avoided. Rest is also important in preventing shock. Unnecessary movements can take blood away from the most vital body parts.
When controlling arterial and venous bleeding, the same measures should be taken. The only difference is the order in which these measures should be carried out, which is different for arterial bleeding than for venous bleeding.