Common causes of unconsciousness
1. Impingent of the blood supply to the brain. This may be a result of:
c. Cardiac arrest
2. Impairment of oxygen supply to the brain. This may result from:
c. Carbon monoxide poisoning
3. Direct damage to the brain, i.e. head injury.
4. Compression of the brain. This may be a result of:
a. Skull fracture
5. Alteration of the chemical balance of the brain's blood supply. This may be caused by:
a. Poisoning (including drugs and alcohol)
b. Low blood sugar (hypoglycemia)
6. Other causes, such as:
b. Abnormally high body temperature
First aid for the unconscious
Unconsciousness is caused by a variety of conditions that interrupt normal brain function. Unlike sleep, the casualty cannot be easily or completely roused in response to stimuli such as sound or pain. The first arider should always bear in mind that there is a danger that the airway will become blocked during unconsciousness, either by vomit or by the tongue falling backwards. Therefore always follow the following steps:
1. Lift the chin and gently tilt the head to open the airway. If the casualty begins to vomit, place in the recovery position (see p.445). If you suspect that there may be spinal injury, open the airway by lifting the chin. Do not attempt to tilt the head.
2. Check breathing and circulation. Be prepared to resuscitate if necessary.
3. Check the casualty for any heavy extreme bleeding or fractures and treat accordingly.
4. Place the casualty in the recovery position (see p.445) if you are satisfied that there is no serious neck or spinal injury (see pp.43~39) for advice on recovery position for a suspected spinal injury).
5. If full consciousness has not been regained within three minutes, telephone 999 for an ambulance. Phone 999 immediately if the casualty is a young child.
- Do not attempt to give the unconscious casualty anything by mouth.
- Do not attempt to move the casualty unnecessarily, or to make him or her sit up.
- Do arrange for the casualty to visit a doctor as soon as possible.
Head injuries and loss of consciousness
The brain is encased within the hard bony skull and cushioned by cerebra-spinal fluid to protect it from injury. It transmits impulses via the spinal chord, which runs down the neck and spine, to all the nerves of the body. The brain and spinal chord are extremely fragile and incapable of repairing themselves, hence the protection of the skull and spine.