by Kerry Lynch
Every cell of the body needs oxygen for its survival and will be damaged and eventually die without it. The cells of the brain, heart and lungs are especially damaged quickly by a shortage of oxygen. This is why it is so important to start resuscitation as soon as possible after normal respiration has stopped, whatever the cause.
Breathing is the process by which oxygen from the air is brought to the tiny air sacs (alveoli) in the lungs. From here the oxygen is transferred to the blood as it flows in tiny vessels (capillaries) alongside the alveoli. The blood carries the oxygen to the cells, pumped by the heart through
the blood vessels (the process of circulation). The lungs, the blood and circulation are the means of transferring the oxygen in the air to the cells of the body.
Food is normally prevented from entering the larynx (voice box) by a muscular valve mechanism (the epiglottis) but in the unconscious or semi-conscious victim this protection may be lost. Air cannot efficiently enter the lungs if food or vomit enter the passages.
BREATHING
During breathing in (inspiration), the muscle of the diaphragm contracts and flattens, each rib moves up and out a little.
Breathing out (expiration) means the diaphragm and the ribs return to a position of rest expelling a quantity of air.
There is about 21% oxygen in inspired air. The body absorbs approximately 4% leaving 17% oxygen in the expired air. This is why Expired Air Resuscitation (E.A.R) is effective.
CONTROL OF BREATHING
Normal respiration is automatic. Living cells require oxygen and energy - providing substances and produce some waste products. One of the most important waste products is carbon dioxide.
Carbon Dioxide is an acid substance which stimulates the respiratory centre in the brain to send nerve impulses to the diaphragm and other respiratory muscles making them contract.
The normal rate of breathing for adults is about 15 to 20 per minute.
BLOOD CIRCULATION
The circulatory system consists of 3 parts : the blood, the heart and the blood vessels (arteries, capillaries and veins).
The heart is the middle organ of the chest behind the sternum, extending to the left side. The heart consists of four pumps : the left and right ventricles and the left and right atriums.
RESPIRATORY FAILURE
Occurs if a victim's breathing becomes inadequate or stops completely. A common cause of respiratory failure is an obstructed or blocked airway which prevents air from reaching the lungs. This may be caused by the tongue falling back and blocking the throat (pharynx), which occurs in unconscious persons.
Other causes are :
CARDIAC ARREST
If the heart stops beating, the brain and heart suffer particularly from the lack of oxygen. Complete cessation of breathing will usually cause the heart to stop beating within a few minutes. A heart attack (a clot blocking a coronary artery) and electric shock also cause cardiac arrest.
In a few minutes of cardiac arrest the cells of the brain will die, the victim is unlikely to make a full recovery.
The three main signs of cardiac arrest are :
RESUSCITATION
Resuscitation is the attempted revival of a nearly dead or apparently dead person. The techniques of resuscitation include the opening of the airway, artificial ventilation of the lungs and external cardiac compression hence the A B C of resuscitation.
D R. A B C
DANGER
RESPONSE
AIRWAY
BREATHING
CIRCULATION
EXPIRED AIR RESUSCITATION (E.A.R)
Step 1 : D - DANGER self preservation. Check for danger to yourself and the victim.
Step 2 : R - RESPONSE call to the victim then shake the shoulder keeping in mind spinal injury.
Step 3 : A - AIRWAY the unconscious victim should be placed on his side. Tilt his head back to open the airway and if necessary remove any foreign material from the mouth. Use by-standers to call for an ambulance or help.
Step 4 : B - BREATHING while supporting the jaw with a Pistol grip the rescuer should LOOK for breathing movements of the lower chest. LISTEN and FEEL for air leaving the victim's month and nostrils. LOOK, LISTEN and FEEL. If breathing is present place him in the recovery position ensuring a clear airway and drainage. If breathing is absent place victim on his back while maintaining backward head tilt and jaw support, give 5 quick breaths of E.A.R within 10 secs. Check carotid pulse.
Step 5 : C - CIRCULATION check the carotid pulse. Hold the victim's head in backward tilt position. Place the fingers on the Adam's apple then slide into the groove to feel the pulse. Check the pulse for 5 to 6 secs. DO NOT feel both sides at the same time as the blood flow to the brain may be obstructed. If no pulse check the other side for 2 to 3 secs. If there is a pulse continue with EAR.
Step 6 : E.A.R. is used to describe the mouth to mouth, mouth to nose and mouth to mask methods as well as the mouth to mouth and nose used on infants. After commencing EAR the carotid pulse should be checked after 1 minute then every 2 minutes.
Jaw Thrust is used if a neck injury is suspected. This method minimises backward head tilt. It is also used if the mouth is difficult to open.
Rate of application of EAR for an adult is approximately 15 per minute (1 every 4 seconds). EAR for children is approximately 20 per minute (1 every 3 seconds) the rescuer should blow in a smaller volume of air guided by the chest rising and falling.
EAR for Infant: it is difficult to keep the airway of an unconscious infant open. The forehead should be held and the point of the chin supported but the head MUST NOT be tilted backward.
The rescuer should place his mouth over the infant's mouth and nose. Then blow in small puffs of air, guided by watching the chest rising and falling. Breathing is approximately 20 per minute (1 every 3 seconds).
Mouth to nose may be used if it is the rescuer's preference, for resuscitation in deep water, by a child on an adult or if poison has been taken. The steps are the same as mouth to mouth except the rescuer's thumb closes the victim's mouth during ventilation and opens it during exhalation.
When the victim resumes breathing for himself he should be placed in the lateral or recovery position.
EXTERNAL CARDIAC COMPRESSIONS (E.C.C)
Step 7 : E.C.C. should be performed when the victim has no pulse. The victim will also be unconscious and not breathing.
EAR and ECC must be used together. This is called CARDIOPULMONARY RESUSCITATION (CPR). The aim of ECC is to give a vertical push which squeezes the heart between the sternum and the spine.
LOCATING THE POINT OF COMPRESSION
Carefully feel around the bottom of the ribs to where they meet the sternum, place your index finger at this point. Locate the upper end of the sternum by feeling the groove between the collarbones. Place your other index finger at this point. Extend the thumbs of each hand to meet in the middle of the sternum. This is called the mid point.
FOR AN ADULT : Keep the thumb of the upper hand in position and place the heel of the lower hand in the middle of the lower half of the sternum with fingers pointing across the chest. Two hands are used for ECC on adults depressing the sternum 4 -5 cms.
ECC FOR CHILDREN (UP TO 8 YEARS) : Locating the mid point is the same as for an adult BUT compressions are applied using one hand depressing the sternum 2.5 cms.
ECC FOR INFANTS : The technique is the same as for children except TWO FINGERS are used to compress the centre of the sternum at a depth of 1.5 cms.
The compressions are made vertical with no pressure exerted on the chest except through the heel of the hand or fingers. Compressions must never be jerky.
CARDIOPULMONARY RESUSCITATION (CPR)
Step 8 : CPR ONE OPERATOR : ADULT - 2 breaths of EAR within 5 seconds followed by 15 compressions within 10 seconds. 4 cycles per minute.
CPR : CHILDREN (up to 8 years) 2 breaths of EAR followed by 15 compressions within 10 seconds. 6 cycles per minute. Infants are the same ratio.
CPR : TWO OPERATORS : ADULT - I breath and 5 compressions in 5 seconds. 12 cycles per minute.
CPR : TWO OPERATORS : CHILDREN AND INFANTS - 1 breath and 5 compressions in 3 seconds. 20 cycles per minute.
CPR should be stopped to check the pulse after I minute then every 2 minutes. CPR must continue until breathing and pulse are restored or medical help arrives.
Step 9 : AFTER CARE : If the carotid pulse returns EAR should continue until breathing resumes. The victim should he put into the lateral or recovery position. When in this position special attention must be given to airway, breathing and circulation. Noisy breathing means the airway is partly blocked either by the tongue or by foreign material.
COMPLICATIONS
AIRWAY OBSTRUCTION : If the chest does not rise during inflation, the rescuer should check :
* maximum head tilt and jaw support
* seal of mouth and nose
* adequate volume of blowing
If after checking these points the chest still doesn't rise, turn the victim onto their side and deliver several sharp thumps between the shoulder blades. This is followed by putting your fingers in the mouth to remove the foreign body. If it is a child they can be upended and the thump delivered, care must be taken with the neck.
VOMITING AND REGURGITATION: These are major problems in unconscious people, especially immersion victims. If stomach contents return to the mouth during EAR they must be quickly turned onto their side, the mouth emptied and breathing checked again. Vomiting may be a sign of recovery.
AIR IN THE STOMACH: Major causes are EAR performed with a partly blocked airway and overinflation. No effort should be made to empty the stomach.