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Improving Outcomes from Out of Hospital Cardiac Arrest: The Cardiac Arrest Individual Registry and Outcomes (CAIRO) Programme

Funding body/stream

NIHR - Programme Development Grant

Chief investigator

Professor Jonathan Benger


University Hospitals Bristol NHS Foundation Trust & University of the West of England, Bristol

Start date and duration

1st October 2013 for 18 months




A cardiac arrest occurs when the heart stops beating suddenly, and is one of the most extreme medical emergencies. 60,000 people suffer a cardiac arrest outside hospital (OHCA) in the UK each year, with resuscitation attempted in less than half, and less than 10% surviving to hospital discharge. Recently available figures also show that there is considerable variation throughout England in both the frequency with which a heartbeat is regained (return of spontaneous circulation; ROSC), and survival.

With support from healthcare commissioners, the hospital care of OHCA is becoming centralised in fewer "heart attack centres". Alongside this concentration of services in Southwest England we plan to implement a programme of research designed to monitor and improve patient care from the initial ambulance response right through to hospital discharge. This is called the "Cardiac Arrest Individual Registry and Outcomes (CAIRO) Programme".

At the centre of this research is a comprehensive patient registry: the CAIRO database. This will allow us to confidentially track each cardiac arrest patient from their initial collapse through to hospital discharge and, with the patient's consent, a follow-up assessment of progress six months later. We will then answer three linked research questions. Each is designed to contribute to our overall research aim: to find ways of ensuring that more people survive with the best possible quality of life.

The three questions are:

1. How can we improve the decisions made by ambulance staff when they start and stop resuscitation attempts?

2. What is the right amount of oxygen to give once a patient has regained a heartbeat?

3. How can we ensure that the very best treatment is consistently given on intensive care units?

Before embarking on a major study of this type we need to be sure that what we are proposing is possible, and will provide valuable results. Therefore this programme development grant aims to demonstrate that the CAIRO database can be successfully created, and that it will be possible to run the research trials that we have designed. We need to be certain that patients can be successfully recruited, that all the necessary information can be collected and that we are using the right treatments and outcome measures.

Research in OHCA patients is very challenging since they are unable to give consent initially, and many treatments have to be provided as quickly as possible. Our team is expert in dealing with these issues, having completed similar research in cardiac arrest and critically ill patients, with the input of patient and public advisers.

We have also engaged experts from the UK and overseas to help and advise us, increasing the chances of success.


60,000 people suffer OHCA in the UK each year, with resuscitation attempted in less than half, and less than 10% surviving to hospital discharge. Recently available figures also demonstrate substantial variability throughout England in both the frequency with which ROSC is achieved, and long-term survival.

Even in those patients achieving ROSC, the proportion surviving to hospital discharge remains disappointingly low. The NHS and societal costs associated with the hospital and subsequent care of OHCA patients are substantial, as they usually require specialised levels of care and may leave hospital with an impaired quality of life. Recent advances in the management of OHCA following ROSC have demonstrated improvements in patient survival, but with significant impact on the associated health and social care costs.

This programme of research aims to identify effective and cost effective interventions throughout the patient pathway of OHCA, thereby providing value for money for the NHS. This is highly relevant to the priorities and needs of the NHS, expressed in the NHS operating framework (DH, 2012); 'NHS organisations should continue to support clinical and research strategies aimed at reducing mortality from cardiovascular disease…'

Patient and public involvement

From the outset we have ensured full patient and public engagement. A survivor of out of hospital cardiac arrest is a co-applicant and he and his wife have attended all team meetings. He spoke powerfully of his experiences at a regional seminar on out of hospital cardiac arrest (OHCA) which took place in January 2012 and was attended by more than 100 clinicians, commissioners and managers. The patient-partner and his wife have reviewed and helped to shape all research documents, with full input into meetings; clearly articulating the patient and carer's view of the entire patient pathway.

We have also engaged with the patient and public forum of Great Western Ambulance Service NHS Trust, which has provided invaluable input and a clear lay steer to this and previous research work in OHCA. This lay group has been particularly helpful in dealing with the ethical issues relating to consent and information, and has supported the development of a successful approach to the complex ethical dilemmas which occur when completing research in incapacitated adults, many of whom do not survive.

We will also convene a dedicated lay group to provide input to all aspects of the programme. Because cardiac arrest can occur suddenly in any individual it will not be necessary to have experience of OHCA in order to join the lay group: indeed, a range of views is required to ensure that the subject is considered from all societal perspectives, gaining a balance of opinion on end of life choices and care.

Links to further information