Who gives the best CPR? Man or machine

The challenge

In the UK, there are over 30,000 cardiac arrests a year and the survival rate is poor -  as few as one in ten of those who arrest outside of hospital survive.

During cardiac arrest, a person’s heart goes into a life threatening rhythm and stops blood pumping around their body and to their brain. It causes the person to fall unconscious and stop breathing. CPR (cardiopulmonary resuscitation) involves giving a combination of chest compressions and mouth-to-mouth ‘rescue breaths’,  keeping blood flowing to the vital organs and maintaining a heart rhythm that will react to defibulation.

The difference in the quality of CPR a patient receives can be the difference between life and death. Compressing the chest to the right depth, at the right rate, without interruption, while allowing it to fully recoil, increase the chance of survival.

For paramedics, maintaining this high standard can be challenging; gaining access to the patient, performing CPR in a moving vehicle, fatigue, operating with a small crew and balancing competing tasks (such as defibrillation) can all affect performance. So could technology - in the form of a mechanical compression device - help?


Practicing CPR

What we did

The NIHR funded research to test the effectiveness of LUCAS-2 - a machine developed to automate and potentially improve CPR that had been added in number of front-line emergency response vehicles. Ninety one ambulance stations took part in the study and patients received chest compression delivered either by LUCAS-2 or by the paramedic manually, depending on which vehicle was the first to arrive on scene.



What we found

The study found no difference in survival rates between patients treated with mechanical compression and those treated manually. The survival rate, measured at 30 days after cardiac arrest, was similar for both groups and the machine did not improve the percentage of patients who survived to reach hospital.  

One of the trial leaders, Professor Gavin Perkins says:

“Our trial suggests there is no survival or neurological advantage for patients who receive mechanical CPR. The trial emphasises the importance of focusing on the basics and doing those well. Getting more people to undertake bystander CPR, improving use of public access defibrillation and getting ambulances to cardiac arrest victims quickly are the key to saving lives.”




Following the study, the Resuscitation Council UK Guidelines were updated, stating:

“We recommend that automated mechanical chest compression devices are not used routinely to replace manual chest compressions ……[except] in situations where sustained high quality manual chest compressions are impractical or compromise provider safety.”

Similar guidance has been provided by the European Resuscitation Council Guidelines for Resuscitation 2015 and the International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Any decision with regards to future investment would need to be balanced against the accepted role of these devices when manual CPR is impractical or presents increased risk to the patient.

Manual chest compressions is used routinely and their is reduced usage of automated mechanical chest compression devices. The study potentially saved the NHS £40 million, by not investing in the mechanical devices and the associated training costs to use them.