Condition category
Circulatory System
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
A cardiac arrest occurs when the heart suddenly stops beating, and is one of the most severe medical emergencies. Over 50,000 people die each year following an out of hospital cardiac arrest (OHCA) in the UK, and less than 10% of patients survive. The immediate treatment for a cardiac arrest is cardiopulmonary resuscitation (CPR): this is a combination of rescue breathing and chest compressions. Prompt and effective CPR is essential to prevent damage to vital organs, and increases the chance of survival. If initial treatments are not effective at restarting the heart, some people are given a drug called adrenaline. Although adrenaline has been used to treat cardiac arrest for a number of years, no one is really sure about whether it is safe and effective for improving long-term survival and helping the brain to recover. Given the uncertainty of the evidence and the life-threatening nature of the condition being treated, it is ethically important that we obtain the best evidence we can to justify treatment, while ensuring that the interests of the research participants remain paramount.
When doctors, nurses and paramedics do not know whether a treatment is effective it is common to undertake a research study. Research studies of this type involve putting people into two groups where one group receive the active drug (in this case adrenaline) and the other group a dummy drug (known as a placebo). The results are compared to see if one is better. To try to make sure the groups are the same to start with, each patient is put into a group by chance (randomly). The study is referred to as a 'double blind trial', as neither the patient nor the paramedic/nurse/doctor will know in which treatment group someone was in. The aim of this study is to work out how safe and effective adrenaline is as a treatment for patients who suffer out of hospital cardiac arrest.

Who can participate?
Patients who suffer from a cardiac arrest in an out of hospital environment being treated with advanced life support that is initiated and/or continued by an ambulance service clinician.

What does the study involve?
The University of Warwick Clinical Trials Unit is carrying out this study with five ambulance services across the UK. We will collect information about 8,000 patients who have been treated for cardiac arrest. Half of the patients will have been treated with adrenaline and half will have been treated with placebo (dummy). The study will look at survival at 30 days after cardiac arrest in both groups and explore the effects of adrenaline on brain function. If the patient wants to take part in the follow up this will involve completing questionnaires about their quality of life and general health at 3 and 6 months after the cardiac arrest.

What are the possible benefits and risks of participating?
For people that receive adrenaline there is the potential that a greater number will have their hearts re-started and will survive in the short term (minutes to hours). For people that receive placebo, the available evidence on long-term survival (survival to hospital discharge) suggests that some people will survive to leave hospital when they would otherwise have died if they had received adrenaline. Participants receiving placebo may also avoid the potential side effects of adrenaline (irregular heartbeat, heart attacks, adverse effects on metabolism and brain injury). Participation in the study will provide critical information about the most effective way to resuscitate future patients that sustain an out of hospital cardiac arrest.

Where is the study run from?
The University of Warwick Clinical Trials Unit is carrying out this study with five ambulance services across the UK.

When is the study starting and how long is it expected to run for?
The study started in March 2014. Data will be monitored regularly by the overseeing committees and the trial may need to stop if a difference is found early. Otherwise data will be collected for three and a half years and results will be known in 2019.

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Warwick Clinical Trials Unit
University of Warwick

Trial website

Contact information



Primary contact

Prof Gavin Perkins


Contact details

Warwick Clinical Trials Unit
The University of Warwick
Gibbet Hill Road
United Kingdom

Additional identifiers

EudraCT number

2014-000792-11 number

Protocol/serial number

HTA 12/127/126, v1.0

Study information

Scientific title

Prehospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug administration In Cardiac arrest



Study hypothesis

Is the use of adrenaline in out of hospital cardiac arrest clinically and cost effective?

More details can be found at:
Protocol can be found at:

Ethics approval

Oxford C REC, 21/05/2014, ref: 14/SC/0157

Study design

Pragmatic individually randomised double blind controlled trial and economic evaluation

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Out of hospital cardiac arrest


Intervention: Adrenaline 1 mg every 5 minutes
Control: Placebo

Intervention type



Not Applicable

Drug names


Primary outcome measure

Survival to 30 days post cardiac arrest

Secondary outcome measures

1. Survived event (sustained ROSC, with spontaneous circulation until admission and transfer of care to medical staff at the receiving hospital)
2. Survival to hospital discharge (the point at which the patient is discharged from the hospital acute care unit regardless of neurological status, outcome or destination) 3, 6 and 12 months
3. Neurological outcome at hospital discharge, 3 and 6 months
5. Health related quality of life at 3 and 6 months
6. Hospital length of stay
7. Intensive care length of stay

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Cardiac arrest in out of hospital environment
2. Advanced life support initiated and/or continued by ambulance service clinician

Participant type


Age group




Target number of participants


Total final enrolment


Participant exclusion criteria

1. Known or apparent pregnancy
2. Known or apparently aged under 16 years
3. Cardiac arrest secondary to anaphylaxis
4. Adrenaline given prior to arrival of ambulance service clinician

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

The University of Warwick
United Kingdom

Sponsor information


University of Warwick (UK)

Sponsor details

Warwick Medical School
United Kingdom

Sponsor type




Funder type


Funder name

Health Technology Assessment Programme

Alternative name(s)

NIHR Health Technology Assessment Programme, HTA

Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date


Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2016 protocol in:
2. 2018 results in:
3. 2020 case study results in (added 16/01/2020)
4. 2020 analysis in (added 03/02/2020)
5. 2019 results in (added 02/09/2020)
6. 2020 cost-effectiveness results in (added 30/09/2020)

Publication citations

Additional files

Editorial Notes

30/09/2020: Publication reference added. 02/09/2020: The following changes have been made: 1. Publication reference added. 2. The total final enrolment number has been added from the reference. 03/02/2020: Publication reference added. 16/01/2020: Publication reference added. 23/01/2019: The overall trial end date has been changed from 17/10/2018 to 31/07/2019. 03/09/2018: Publication reference added. 23/05/2018: The following changes have been made: 1. The recruitment start date has been changed from 01/03/2014 to 23/12/2014. 2. The recruitment end date has been changed from 01/08/2018 to 18/11/2017. 3. The overall trial end date has been changed from 01/08/2018 to 17/10/2018. 22/09/2016: Publication reference added.