CPR is effectively squashing the heart between the spine and the breast bone so that blood is forced out of it. There is a lot of recent evidence that suggests that effective CPR with minimal interruptions is crucial in terms of improving survival.
Performing chest compressions at the correct rate and depth is extremely tiring. The more tired you become, the poorer the quality of the compressions will be. Team work is vital and using other bystanders who are trained in CPR to take turns or even “coaching” someone who is not is preferable to a lone tired rescuer.
European Resuscitation Council (ERC) guidelines and American Heart Association (AHA) guidelines
Resuscitation guidelines are based on evidence-based research and general consensus from the International Liaison Committee on Resuscitation (ILCOR). Whilst all of the guidelines are based on evidence and consensus from the expert group, there are a few minor variations between European Resuscitation Council (ERC) guidelines and American Heart Association (AHA) guidelines. The same main message persists no matter which guideline you follow, the emphasis is on good quality CPR and early defibrillation.
Good quality CPR is delivered by giving:
- Compressions at a rate of 100 per minute.
- Depth of at least two inches
- Minimal hands off time/ minimise interruptions in chest compressions
- Allow complete chest recoil
Research has shown that lay responders can find it difficult to recognise cardiac arrest and agonal breathing is a major distracter in recognising cardiac arrest. Many victims of cardiac arrest do not receive CPR because of lack of recognition of cardiac arrest and the fear of doing wrong among bystanders. With this in mind, the AHA in their 2010 guidelines decided to remove the head tilt / chin lift technique in the initial airway opening sequence. The lay rescuer should approach the victim checking firstly that the area is safe for their approach. Gently tap the victim’s shoulders and check for response. If there is no response, call for the emergency services and call for an AED. Then scan the chest for normal breathing. If the victim is not breathing normally, place the heel of one hand on top of the other in the centre of the chest and commence compressions immediately. The sequence here differs slightly from the ERC sequence. The responder continues CPR at a rate of 30 compressions to two breaths. When the AED arrives, attach the AED. 30 compressions and 2 breaths are the same in both ERC and AHA guidelines. The AHA for simplicity state that the compression rate should be at least 100 compressions but they do not state an upper limit.
No matter which guidelines you choose to follow, remember you can do no harm by performing CPR on an unresponsive victim. If you have no AED available, continue compressions and breaths until you hand over to the emergency services. Remember, the more continuous compressions, the better the victims chance of survival.
If you are in a position where you do not wish to give breaths to the victim, “hands only CPR” is still a very good option for the victim. Commencing CPR early doubles the victim’s chances of survival.