Targeted therapeutic mild hypercapnia after resuscitated cardiac arrest: A phase III multi-centre randomised controlled trial

A cardiac arrest occurs when the heart stops pumping blood to the brain and other major organs. Approximately 10,000 people die from cardiovascular disease every year in Ireland. It is estimated that 5,000 of these deaths are from a sudden cardiac arrest. Early resuscitation (CPR) can get the heart pumping again but in many cases the blood flow to parts of the brain is not as good as before. These patients require transfer to the Intensive Care Unit and need help with their breathing on a breathing machine. This lack of brain blood flow can lead to long term serious disability and sadly many still die in hospital.

We are not sure why the blood flow to the brain changes after successful CPR. We think it might be because the blood vessels of the brain in some areas shrink to allow blood to flow to other important parts of the brain when they realize that the heart has stopped pumping. Normally the blood flow to our brain blood vessels is controlled by the amount of carbon dioxide levels in the blood. Therefore, by adjusting the amount of carbon dioxide in the blood after a cardiac arrest this may help restore blood flow to all of the brain.

This trial will investigate whether those who have slightly more carbon dioxide in their blood do better after cardiac arrest than those who are treated normally. We can easily adjust the amount of carbon dioxide in the blood while on the ventilator in the intensive care unit using the equipment we use every day.

If we are right this will potentially prevent many deaths for people in Ireland and all around the world from cardiac arrest and greatly improve the outcome of those who have experienced a cardiac arrest and survived.


Award Date
24 February 2017
Award Value
Principal Investigator
Professor Alistair Nichol
Host Institution
University College Dublin
DIFA 2017