There will hardly be any nurse who has not had a patient suffer a cardiac arrest.
We all have experienced that dreadful moment when you find a patient has an undetectable pulse and is unresponsive.
Or they have stopped breathing or they are breathing abnormally either apnoea or gasping respirations.
Then your training kicks in.
Cardiopulmonary resuscitation (CPR) is the treatment for cardiac arrest.
Most nurses will have used the conventional method of CPR of chest compression and rescue breathing such as mouth to mouth.
A ratio of 2 breaths to 15 compressions, or 2 breaths to 30 compressions, are the usual rescue breathing protocols.
External chest compression provides partial circulatory support while rescue breathing improves blood oxygen saturation.
In the hospital or clinic situation, rescue breathing is usually provided by an airway device such as a bag-valve mask.
In the event of a cardiac arrest out of hospital, CPR has been done in the conventional mouth to mouth way.
Or with continuous chest compression only.
In this instance, the person performing CPR does not interrupt compressions to perform artificial ventilation.
CPR in these circumstances improves the chances of survival prior to the arrival of emergency medical services.
A 49 page Cochrane (nearly 20,000 words) review looked at the effects of conventional CPR versus continuous chest compression (only) CPR.
Because most bystanders are reluctant to perform mouth to mouth ventilation.
The outcome of comparing the two types of CPR shows the latter has a better outcome for survival.
The longer circulation is interrupted leads to a lower incidence of return to spontaneous circulation, and less success than with defibrillation.
The Cochrane review concluded that continuous chest compression only CPR leads to more people surviving to hospital discharge.
There is a difference in survival between people who have a non-asphyxial cardiac arrest and an asphyxial cardiac arrest.
A non-asphyxial cardiac arrest is usually a loss of functional cardiac electrical activity.
An asphyxial cardiac arrest is caused by a lack of oxygen in the blood such as occurs with drowning or choking.
The important point is that people, who have continuous chest compression, survive only when it has been a non-asphyxial cardiac arrest outside a hospital.
25 out of 1000 people will survive who have had continuous cardiac compression performed by untrained bystanders who were assisted by receiving telephone instructions from emergency services.
On the other hand, the reviewers found that continuous chest compression CPR performed by professional providers led to a slightly lower rate of survival to admission or discharge, favourable neurological outcome and return of spontaneous circulation.
In short, there is a role for continuous chest compression only CPR when a cardiac arrest occurs out of hospital.
The reviewers suggested further studies that evaluated adverse effects following CPR as well as the impact on long term neurological outcomes and quality of life.
It is unclear whether continuous chest compression is appropriate for paediatric cardiac arrest.
To learn more about the effects of CPR,
Zhan L, et al. Continuous chest compression versus interrupted chest compression for cardiopulmonary resuscitation of non-asphyxial out-of-hospital cardiac arrest. Cochrane Database Syst Rev 2017;3:CD010134.