Two person CPR is less tiring than single person CPR. However, it is important that both rescuers are proficient and practised in the technique. Therefore it is recommended that this technique is only used by trained healthcare providers and those lay persons who are members of trained teams, such as first aid and rescue organisations. The following points should be noted:

1. The first priority is to summon help. This may mean that one rescuer has to start CPR alone whilst the other leaves to find a telephone.
    
2. It is preferable that the rescuers work from opposite sides of the victim.
    
3. A ratio of 15 compressions to 2 inflations should be used. By the end of each series of 15 compressions, the rescuer responsible for ventilation should be positioned ready to give 2 inflations with the least possible delay. It is helpful if the rescuer giving compressions counts out aloud.
    
4. Chin lift and head tilt should be maintained at all times. Ventilations should take 2 seconds each during which chest compressions should cease; they should be resumed immediately after the second inflation of the chest, waiting only for the rescuer to remove his lips from the victim's face.
    
5. If the rescuers wish to change places, usually because the one giving compressions becomes tired, this should be undertaken as quickly and smoothly as possible.

Rescue Breathing

a) Only a small amount of resistance to breathing should be felt during rescue breathing and each rescue breath should take 2 seconds.

b) If inflation is too quick resistance will be greater and less air will get into the lungs.

c) The tidal volume to be achieved is about 700 - 1000 ml in an adult, which is the amount normally required to produce visible lifting of the chest.

d) The rescuer should wait for the chest to fall fully during expiration before giving another breath. This should normally take about 2 - 4 seconds; each sequence of 10 breaths will therefore take about 40 to 60 seconds to complete.

e) The exact timing of expiration is not critical; the chest should be allowed to fall before another breath is given.

 

Chest compression

a) In an adult the aim should be to press down approximately 4-5 centimetres and apply only enough pressure to achieve this.

b) At all times the pressure should be firm, controlled and applied vertically. Erratic or violent action is dangerous.

c) The recommended rate of compression is a rate and not the number of compressions which are to be given in a minute; this will depend upon interruptions for rescue breathing.

d) About the same time should be spent in the compression phase as in the released phase.

e) As the chances are remote that effective spontaneous cardiac action will be restored by BLS without other techniques of advanced life support (including defibrillation), time should not be wasted by further checks for the presence of a circulation. If, however, the victim makes a movement or takes a spontaneous breath, the rescuer should check for signs of a circulation; take no more than ten seconds to do this. Otherwise resuscitation SHOULD NOT BE INTERRUPTED.

f) The presence of dilated pupils has in the past been variously used as a sign of cardiac arrest, failure of the circulation during resuscitation, and the presence of established brain damage. This sign is unreliable and should not be used to influence management decisions before, during, or after cardiopulmonary resuscitation.

 

Choking

If blockage of the airway is only partial, the victim will usually be able to clear it by coughing, but if obstruction is complete urgent intervention is required to prevent asphyxia.

Victim is conscious and breathing, despite evidence of obstruction:

• Encourage him to continue coughing but do nothing else

   If the victim is conscious:

• Carry out back blows:
  • Remove any obvious debris or loose teeth from the mouth
  • Stand to the side and slightly behind him
  • Support his chest with one hand and lean the victim well forwards so that when the obstructing object is dislodged it comes out of the mouth rather than goes further down the airway
  • Give up to 5 sharp blows between the scapulae (shoulder blades) with the heel of your other hand; each blow should be aimed at relieving the obstruction, so all 5 need not necessarily be given.
   
• If the back blows fail, carry out abdominal thrusts:
  • Stand behind the victim and put both your arms around the upper part of the abdomen
  • Make sure the victim is bending well forwards so that when the obstructing object is dislodged it comes out of the mouth rather than goes further down the airway.
  • Clench your fist and place it between the umbilicus (navel) and xiphisternum (bottom tip of the sternum). Grasp it with your with your other hand
  • Pull sharply inwards and upwards; the obstructing object should be dislodged
  • If the obstruction is still not relieved, recheck the mouth for any obstruction that can be reached with a finger, and continue alternating 5 back blows with 5 abdominal thrusts.

   If the victim at any time becomes unconscious:

• Tilt the victim's head and remove any visible obstruction from the mouth
• Open his airway further by lifting his chin
• Check for breathing by looking, listening, and feeling
• Attempt to give 2 effective rescue breaths
• If effective breaths can be achieved within 5 attempts:
  - Check for signs of a circulation
  - Start chest compressions and/or rescue breaths as appropriate
  
• If effective breaths cannot be achieved within 5 attempts:
  - Start chest compressions immediately to relieve the obstruction. Do not check for signs of a circulation
  - After 15 compressions, check the mouth for any obstruction, then attempt further rescue breaths
  - Continue to give cycles of 15 compressions followed by attempts at rescue breaths
• If at any time effective breaths can be achieved:
  - Check for signs of a circulation
  - Continue chest compressions and/or rescue breaths as appropriate.

Mouth-to-nose ventilation

There are several situations in which mouth-to-nose ventilation may be preferable to mouth-to-mouth ventilation:
 
a) If mouth to mouth ventilation proves technically difficult, for example because of unusual or absent dentition
 
b) If mouth obstruction cannot be relieved
 
c) During rescue of a victim from the water, when one hand is required to support the body and cannot be used to close the nose
 
d) When resuscitation is being carried out by a child whose mouth may not be large enough to seal an adult's mouth
 
e) For aesthetic reasons
 
To carry out mouth-to-nose ventilation:

• Release the victim's nose and close his mouth
• Seal your mouth around his nose and blow in steadily as for the mouth-to-mouth technique
• Allow his mouth to open to let the breath out.

Cervical spine injury

If spinal cord injury is suspected (for example if the victim has sustained a fall, been struck on the head or neck, or has been rescued after diving into shallow water) particular care must be taken during handling and resuscitation to maintain alignment of the head, neck, and chest in the neutral position. A spinal board and/or cervical collar should be used if available. As hypotension often accompanies spinal cord injury care should be taken to maintain the victim in a horizontal position during rescue.

When obtaining an airway, head tilt may be employed, but the tilt should be the minimum that allows unobstructed ventilation or intubation. Jaw thrust rather than chin lift is preferable. During resuscitation, assistance from others may be required to maintain head, back, and chest alignment if adequate splinting is not available. Remember that successful resuscitation that results in paralysis is a tragedy, but failure to carry out adequate ventilation in cases of respiratory arrest will result in death.