Blunt Injuries
The term blunt injury is used to describe a rupture in soft tissue caused by external violence, where the skin remains intact. The bleeding causes swelling to occur. The extent of the swelling is determined by:
- The severity of the injury.
- The speed with which blood clotting takes place.
- The elasticity of the surrounding tissue.
Once the vessel wall is damaged, the blood vessels constrict and the clotting mechanism is activated. As long as the clotting process has not been completed and the pressure of the tissue on the ruptured capillary vessels is lower than that in the blood vessel, blood will fill the available space in the tissue and, if possible, push the tissue aside.
As the elasticity of the tissue is limited, or because the site of the bleeding is surrounded by bone, the pressure will rise. Once this pressure is equal to or higher than that in the blood vessels, the bleeding will decrease and conditions will become more favourable for blood clotting. This counter-pressure acts as a natural compression bandage.
This chapter will only describe treatment of blunt injuries involving limbs. Blunt injuries to the skull, abdominal and chest cavities are less common but generally more serious and rapidly lead to disturbances in vital functions. These injuries require specialist treatment.
A blunt injury can arise in two ways:
- The tissue can be compressed between an external force exerted on the body and bone tissue.
- As a result of abnormal movements which excessively stretch the tissue structure. The two points of connection for muscles or tendons are stretched further apart than permitted by the tissue’s elasticity.
A blunt injury is usually classed according to the cause. If the tissue has been compressed between an external force acting on the body and the bone, the injury is known as a contusion or bruise. Tissue damage caused by bones involved in a fracture is also known as a contusion. In both cases, the skin remains intact, but the subcutaneous connective tissue, muscles, tendons or supportive tissue around the joint are bruised.
The signs of a contusion are as follows:
- Pain, usually short-lasting.
- Swelling, with bluish discolouration after some time.
- Impaired function – the extent depends on the site and severity of the injury.
The severity of a contusion is often underestimated because the skin remains intact and discolouration only develops some time later. If the skin is damaged, there may well be bruising of the underlying tissue, but it is nonetheless treated as an open wound.
A sprain involves damage to ligaments or to the site where the ligament attaches to the bone. Ligaments protect a joint against abnormal movements. If a sudden extreme movement or constant overload causes a ligament to overstretch, damage will occur. The ligament can tear or rupture fully.
The damage will generally not be restricted to the ligament, but instead the surrounding tissue will also be bruised.
The signs of a sprain are:
- Severe pain in and around the joint immediately after the injury occurs.
- Pain upon palpation at the site of the ligament. The pain will only be felt in the area around the ligament upon movements which involve active and passive movement of the damaged ligament.
- Swelling, later accompanied by bluish discolouration.
- Loss of function.
In the case of luxation (dislocation), the sprain is so severe that the head of the joint remains fully or partially displaced. Partial dislocation is called subluxation. The ligaments may remain fully extended and, due to this extension, damage the nerves and blood vessels.
The signs of luxation are:
- Severe pain.
- Complete immobility in the joint.
- Abnormal shape of the joint due to shift in joint parts.
- Swelling due to vascular congestion and bleeding.
First Aid
First aid for all forms of blunt injuries generally aims to prevent or limit bleeding. Bleeding causes circulatory problems due to pressure on the surrounding tissue, delaying the tissue repair process. The use of muscles and joints is difficult or avoided due to the pain.
By cooling the affected body part immediately after the accident, the local blood vessels will constrict. The blood supply to the affected area will be reduced, pressure on the opening in the blood vessel will decrease and the blood clotting process will be promoted.
Cooling can be carried out using:
- Cold, flowing water.
- Ice.
- Wet cloths (heat is removed from the body through evaporation).
- Cold-packs.
- Ethyl chloride.
The site of injury should be cooled for at least 20 minutes. The acronym RICE is a useful mnemonic when providing first aid:
- R for rest (immobilisation). By avoiding any muscle activity, the tissue’s oxygen requirement is reduced, and thus the blood supply remains limited.
- I for ice (cooling).
- C for compression in the form of a compression bandage.
- E for elevation, or raising the wounded part of the body. Gravity causes a relative reduction in the blood volume. The supply of arterial blood is reduced, while return of venous blood is stimulated.
In the case of a sprain, no load should be put on the joint for at least 48 hours, and thereafter the pain threshold should not be exceeded.
Depending on the severity of the injury, the treatment can be continued with one of the following measures:
- Keep the compression bandage applied.
- Apply a support bandage using bandaging or tape.
- Immobilise the joint using a plaster cast.
- In severe cases where the ligaments or muscles are completely ruptured, surgery may be necessary.
In the case of a luxation, there is little benefit in treating the consequences of the injury if the cause itself has not been resolved. First aid should involve repositioning the joint. If this has to happen in the clinic, cooling and rest can be used to control any bleeding and pain during the journey. After repositioning, treatment should be the same as for sprains.