To stay alive we need an adequate supply of oxygen to enter the lungs and be transferred to all cells in the body by the circulating blood. If a person is deprived of oxygen for any length of time, the brain will begin to fail.
As a result, the casualty will eventually lose consciousness, breathing will cease. the heart will stop and death results.
The airway must be kept open so that breathing can occur, allowing oxygen to enter the lungs and be circulated in the body.
Therefore, the priority of a first aider when treating any collapsed casualty is to establish an open airway and maintain breathing and circulation.
An automated external defibrillator (AED) may be required to “shock” the heart back into a normal rhythm. This chapter outlines the priorities to remember when dealing with an unconscious casualty.
There are important differences •rcthe treatment for unconscious children and adults,’ this chapter gives separate step-by-step instructions for dealing with each of these groups.
BREATHING AND CIRCULATION
Oxygen is essential to support life. Without it, cells in the body die – those in the brain survive only a few minutes without oxygen.
Oxygen is taken in when we breathe in and it is then circulated to all the body tissues via the circulatory system. It is vital to maintain breathing and circulation in order to sustain life.
The process of breathing enables air, which contains oxygen, to be taken into the air sacs (alveoli) in the lungs. Here, the oxygen is transferred across blood vessel walls into the blood, where it combines with blood cells.
At the same time, the waste product of breathing, carbon dioxide, is released and exhaled in the breath. When oxygen has been transferred to the blood cells it is carried from the lungs to the heart through the pulmonary veins.
The heart pumps the oxygenated blood to the rest of the body via blood vessels called arteries. Deoxygenated blood is brought back to the heart by blood vessels called veins. The heart pumps this blood to the lungs via the pulmonary arteries,
where the carbon dioxide is released and the blood is reoxygenated before circulating around the body again.
The procedures set out in this chapter can maintain a casualty’s breathing and circulation until emergency help arrives. With an unconscious casualty, your priorities are to maintain an open airway, to breathe for the casualty (to get oxygen into the body), and to maintain blood circulation (to get oxygenated blood to the tissues).
In an adult during the first minutes after the heart stops [cardiac arrest), the blood oxygen level remains constant, so chest compressions are more important than rescue breaths in the initial phase of resuscitation. After about five minutes, the blood oxygen level falls and rescue breathing becomes more important.
The combination of chest compressions and rescue breaths is called cardiopulmonary resuscitation, or CPR. In addition to CPR. a special machine called an automated external defibrillator IAED) can be used to deliver an electric shock that may restore a normal heartbeat In children and infants, a problem with breathing is the most likely reason for the heart to stop.
They are therefore given FIVE initial rescue breaths before chest compressions are started.
If all of the following elements are complete, the casualty’s chances of survival are as good as they can possibly be:
•Emergency help is called quickly;
•CPR is used to provide circulation and oxygen;
•AED is used promptly;
•Specialised treatment and advanced care arrive quickly.