Out-of-Hospital Cardiac Arrests: The Role of CPR & AEDs

AED & Fire Extinguishers, both necessary
AED (Photo credit: Frederick Md Publicity).

Current UK survival rates among people who have a cardiac arrest outside hospital remain extremely poor, varying from 2% to 12% (Perkins & Cooke, 2012).

Every year an estimated 60 000 out of hospital cardiac arrests occur in the UK, 30 000 of which are treated by emergency medical services (Pell et al., 2003; Berdowski et al., 2010).

Optimal use of the “chain of survival” (the sequence of interdependent treatment actions for cardiac arrest) is what makes the difference between life and death. Predictors of survival include time to the first emergency response; whether the arrest is witnessed; effective bystander cardiopulmonary resuscitation (CPR); initial shockable rhythm; early defibrillation; and pre-hospital return of spontaneous circulation (Sasson et al, 2010).

Although the links within this chain of survival are paramount, early defibrillation is crucial, with a 10% decrease in survival with every minute of delay (Nolan et al., 2010). CPR, when combined with effective defibrillation for shockable rhythms and appropriate post-resuscitation care, results in survival rates that exceed 50% (Cave et al., 2010). Lessons can be learnt from Seattle, which this year reported the world’s highest rate of survival, at 56%, from witnessed cardiac arrests of cardiac origin with a shockable rhythm (also known as Utstein survival) (Payne, 2013).

Such a laudable statistic can be attributed to a 30 year history in Seattle and the surrounding King County of CPR being taught in physical education lessons at all schools; over half the population is now fully trained. The American Heart Association recommends that CPR and familiarisation with automated external defibrillators be required as a condition of graduation from all US state secondary schools (Cave et al., 2010).

In comparison, UK surveys show that only one in 13 respondents were confident in their ability to carry out emergency first aid (BBC News, 2009). Data from the London Ambulance Service show that the Utstein survival in 2012 was 32% (London Ambulance Service NHS Trust, 2011). The Oliver King foundation, set up in memory of a 12 year old boy who died after he had a sudden cardiac arrest while swimming at school, succeeded in ensuring the provision of an automated external defibrillator in every primary and secondary school in Liverpool. The foundation’s estimate is that 12-16 young people die from a sudden cardiac arrest every week in the UK (Oliver King Foundation, 2013). The Royal College of Paediatrics and Child Health and the BMA have supported calls for every public building, including schools, sports and fitness centres, and football stadiums, to have an automated external defibrillator (Defibshop, 2013). Coronary artery disease is responsible for 40-90% of out of hospital cardiac arrests (Stub et al., 2011).

As well as Seattle, we can learn lessons from Norway, where appropriate allocation of resources to this link in the chain of survival has reduced mortality (Lindner et al., 2011; Laerdal, 2011). The British Heart Foundation should be commended for raising awareness through a national advertising campaign on the importance of CPR (British Heart Foundation, 2013). Its policy statement calling for the UK governments to ensure the inclusion of emergency life support as a key development skill in all secondary schools should be supported and implemented (British Heart Foundation, 2011).

Scientific evidence to support early defibrillation for cardiac arrest that occurs secondary to ventricular fibrillation or pulseless ventricular tachycardia is overwhelming. Delay from collapse to delivery of the first shock is the most important determinant of survival, and survival rates after prompt defibrillation as high as 75% have been reported (Resuscitation Council (UK) (2010). Automated external defibrillators (AEDs) are sophisticated, computerised devices that are reliable and simple to operate, and their statutory provision in public places could save thousands of lives. It is perhaps instructive to note that UK parliamentary premises currently have 16 such devices (BBC News, 2013).

Last month the British Heart Foundation said that the number of people dying from cardiac arrests was “unacceptable” and rightly reinforced the message that all schoolchildren should be taught CPR (Huffington Post, 2013). By learning from the tragedy of Oliver King we should implement the evidence that will help save thousands of lives.


Perkins, G.D. & Cooke, M.W. (2012) Variability in Cardiac Arrest Survival: The NHS Ambulance Service Quality Indicators. Emergency Medical Journal. 29, pp.3-5.

Pell, J.P., Sirel, J.M., Marsden, A.K., Ford, I., Walker, N.L. & Cobbe, S.M. (2003) Presentation, Management, and Outcome of Out of Hospital Cardiopulmonary Arrest: Comparison by Underlying Aetiology. Heart. 89, pp.839-842.

Berdowski, J., Berg, R.A., Tijssen, J.G. & Koster, R.W. (2010) Global Incidences of Out-of-hospital Cardiac Arrest and Survival Rates: Systematic Review of 67 Prospective Studies. Resuscitation81, pp.1479-1487.

Sasson, C., Rogers, M., Dahl, J. & Kellermann, A.L. (2010) Predictors of Survival from Out-of-hospital Cardiac Arrest: A Systematic Review and Meta Analysis. Circulatory and Cardiovascular Quality and Outcomes. 3, pp.63-81.

Nolan, J.P., Soar, J., Zideman, D.A., Biarent, D., Bossaert, L.L., Deakin, C., et al. (2010) European Resuscitation Council Guidelines for Resuscitation 2010. Section 1: Executive Summary. Resuscitation. 81, pp.1219-1276.

Cave, D.M., Aufderheide, T.P., Beeson, J., Ellison, A., Gregory, A., Hazinski, M.F., et al. (2011) Importance and Implementation of Training in Cardiopulmonary Resuscitation and Automated External Defibrillation in Schools: A Science Advisory from the American Heart Association. Circulation. 123, pp.691-706.

Payne, P. (2013) Seattle’s Survival Rate for Cardiac Arrest Rises. Puget Sound Business Journal 8 Jan 2013. Available from World Wide Web: www.bizjournals.com/seattle/blog/2013/01/seattles-survival-rate-for-cardiac.html. [Accessed: 03 August, 2013].

BBC News. (2009) Many “lacking first aid skills.” 10 Sep 2009. Available from World Wide Web: http://news.bbc.co.uk/1/hi/health/8246912.stm. [Accessed: 03 August, 2013].

London Ambulance Service NHS Trust. (2011) Cardiac Arrest Annual Report: 2011. 12. Aug 2012. Available from World Wide Web: www.londonambulance.nhs.uk/about_us/idoc.ashx?docid=445f8194-7174-4255-a37a-7f6c5bf2d75e&version=-1. [Accessed: 03 August, 2013].

Oliver King Foundation. (2013) About Us. Available from World Wide Web: www.theoliverkingfoundation.co.uk/aboutus.html. [Accessed: 03 August, 2013].

Defibshop. (2013) Letter to PM Urging Defibrillators in Public Places. 12 Mar 2013. Available from World Wide Web: https://www.defibshop.co.uk/letter-to-pm-urging-defibrillators-in-public-places.html. [Accessed: 03 August, 2013].

Stub, D., Bernard, S., Duffy, S.J. & Kaye, D.M. (2011) Post Cardiac Arrest Syndrome: A Review of Therapeutic Strategies. Circulation. 123, pp.1428-1435.

Lindner, T.W., Søreide, E., Nilsen, O.B., Torunn, M.W. & Lossius, H.M. (2011) Good Outcome in Every Fourth Resuscitation Attempt is Achievable – An Utstein Template Report from the Stavanger Region. Resuscitation. 82, pp.1508-1513.

Laerdal. (2011) Survival Rates up another 7% in the Stavanger Region. Available from World Wide Web: www.laerdal.com/gb/docid/48812701/Survival-rates-up-another-7-in-the-Stavanger-region. [Accessed: 03 August, 2013].

British Heart Foundation (2013) Vinnie Jones’ Hard and Fast Hands-only CPR. Available fro mWorld Wide Web: www.youtube.com/watch?v=ILxjxfB4zNk. [Accessed: 03 August, 2013].

British Heart Foundation. (2011) Policy Statement: Emergency Life Support. Available from World Wide Web: www.bhf.org.uk/pdf/Emergency%20Life%20Support%20policy%20statement%20Apr%202011.pdf. [Accessed: 03 August, 2013].

Resuscitation Council (UK) (2010) The Use of Automated External Defibrillators. Available from World Wide Web: www.resus.org.uk/pages/aed.pdf. [Accessed: 03 August, 2013].

BBC News. (2013) Charlotte Underwood Death: School Defibrillators Petition. 20 Jun 2013. Available from World Wide Web: www.bbc.co.uk/news/uk-england-hereford-worcester-22984588. [Accessed: 03 August, 2013].

Huffington Post. (2013) Teach School Children CPR to Save Lives, Urges British Heart Foundation. 25 Jul 2013. Available from World Wide Web: www.huffingtonpost.co.uk/2013/07/25/teach-school-children-cpr-save-lives_n_3650428.html. [Accessed: 03 August, 2013].


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