Shock is a condition of severe depression of the vital functions. It is associated with changes in the circulatory system varying from temporary weakness to complete failure. Its severity varies with the nature and extent of the injury and it is a common cause of death following severe injuries.
Shock may develop at once or its onset may be delayed. It is important to remember that this delay may occur because the absense of signs and symptoms may give rise to the false sense of security, or lead to the effects of the injury being under estimated.
Loss of whole blood or plasma from the circulation is the most important cause of shock. Severe shock coming on soon after most injuries other than burns is almost always dur to bleeding to the outside into the tissues or the body cavities. In the case of burns there canbe considerable loss of plasma into the tissues.
A simple fracture of the femurcan cause the loss of 20-30 percent of the blood volume by concealed heamorrhage in the thigh. Compound fractures of the tibia and fibula can cause the loss of 15-20 per cent of the total blood volume. In multiple injuries each contributes its shaare of blood loss.
The severity of shock depends on the amount and rapidity of the bleeding. To begin with the circulatory system may be able to adapt itself to the loss of blood and continue to function more or less adequately, but the condition of the casualty will become more critical as time passes unless the bleedingis stopped and the blood volume restored by transfusion.
TYPES OF SHOCK
There are two types of shock:-
2. Established Shock
GENERAL SIGNS AND SYMPTOMS OF SHOCK
These may vary from a transient attack of faintness to state of collapse, and there may be:-
1. Giddiness and faintness
5. Cold clammy skin
6. A slow pulse at first which tends to become progress sively more feeble and rapid.
1. Nerve Shock
All forms of shock involve some nervous reaction but it is possible to describe separately a type of shock which is caused entirely by nervous factors. The effect on the circulation is to cause a fall in blood pressure but this need not be associated with any reduction in the volume of circulating blood.
2. Established Shock
Casualities with more than minor injuries are liable to develop a more serious condition called established shock. This may be expected when there are obvious major injuries; but when the injuries are deep and bleeding is concealed the condition of the casuality is just as dangerous.
If there is failure of circulation, shock will increase, producing symptoms and signs of established shock. These are as stated above but more pronounced and the casualty’s colour may become ashen grey. Collapse will be more obvious and the pulse more feeble.
GENERAL TREATMENT OF SHOCK
- Reassure the casualty
- Lay him on his back with the head low and turned to one side unless there is an injury to the head, abdomen or chest when the head and shoulders should be slightly raised and supported. If he has vomitted or if there is interference with breathing, place him in the three-quarter prone position.
- Loosen clothing about the neck, chest and waist
- Wrap him in a blanket or rug
- If he complains of thirst he may be given sips of water, tea, coffee or other liquid but not alcohol
- Do not apply heat or friction to the limbs. Hot water bottles should not be used.
SPECIAL TREATMENT OF ESTABLISHED SHOCK
Proceed as already described but bear in mind that in severe cases, transfussion and surgery are matters of grave urgency if life is to be saved. It is therefore unwise to delay transfer to hospital for as long as even five minutes except to deal with failing respiration, to stop severe bleeding, to dress a sucking wound of the chest or to secure a limb badly broken.
- Do not give anything by mouth (the casualty may require an anaesthetic)
- Tilt the stretcher so that the level of the head is lower than the rest of the body, except in cases of head, chest or abdominal injury.