Researchers at Warwick University will investigate fears that adrenalin may cause severe brain damage while doing nothing at all to aid survival

Cardiac arrest patients will be given an injection of a useless placebo, instead of the normal adrenalin shot under a medical trial to be conducted this autumn.

During the trial, paramedics will be given randomised treatment packs and will not know whether they are injecting adrenalin or just a salt water solution.

Adverts where the trial is due to take place - the Welsh, West Midlands, North East, South Central and London Ambulance Service areas – will tell people what is happening and allow them to say in advance that they would not consent to taking part if they suffered a cardiac arrest. 

The Paramedic2 Adrenalin trial, which is being led by researchers at Warwick University has been approved by an ethics committee. 

The University of Warwick researchers say the trial is needed because of serious fears that adrenalin may cause severe brain damage while doing nothing at all to aid survival.

But the scientists have conceded that since those suffering cardiac arrest usually lose consciousness within seconds, and because it might be difficult to check up on pre-registered refusal during the scramble to save someone’s life, confirming the consent of the trial participants could be difficult.

A protocol for the trial available via Warwick University Medical School’s website also states that if someone involved dies before there has been a chance to tell them about their involvement in the research, their relatives will not be actively sought out and informed.

Instead they will have to first spot an advert about the trial, and then decide to phone a number to ask whether their dead relative had been one of the research subjects who might have received a shot of saline solution instead of adrenalin.

Explaining why the researchers had decided on this “passive” method of communication, the authors of the protocol said: “Suffering the sudden unexpected loss of a loved one due to cardiac arrest is a traumatic event that frequently leads to symptoms of anxiety, depression and post-traumatic distress.

“Careful consideration therefore needs to be given to how, when and if the relatives of non-survivors are informed about participation in the trial.

“An advantage of passive methods is that they allow people to make a choice about whether they wish to seek further information and the timing of that approach.

“The disadvantage of passive methods is that one cannot be certain that relatives of all participants will see them.

“Our assessment is that the burden of actively informing them will outweigh the potential benefit. “We have discussed this in detail with our clinical ethicist and patient representatives and have their support for this approach.”

Dr Martin Underwood, of Warwick University, told the Telegraph that there was a real need for the research. 

He said: We do not know that adrenalin does improve survival.  It may in fact be something that is custom and practice that is actually harming people.

“It is possible that it improves short-term survival but [that] few patients leave hospital and it may be at the cost of neurological damage.

“There are sufficient grounds for concern that what we are doing at the moment is detrimental to people.”

 He added that all other resuscitation including heart massage and defibrillation would be conducted on every patient, insisting: “We wouldn't expect people would be put at unnecessary risk by this.”