Patients no longer have to wait for life-saving blood transfusions until they get to a hospital.
Major haemorrhage is one of the top causes of major trauma but, until now, patients had to be brought to the hospital's emergency department to receive a blood transfusion.
St Vincent's University Hospital, together with the voluntary group, Wicklow Rapid Response, is now able to provide blood and plasma at the scene of a traumatic event.
The WRR vehicle and volunteer doctor is called simultaneously with the state services when a serious emergency occurs.
To date, the only method for pre-hospital medics to resuscitate bleeding patients was to use saline solution but it is not an ideal treatment because it does not carry oxygen or aid clotting.
Consultant in emergency medicine at SVUH, Dr David Menzies, said a small but important number of patients might benefit from the new on-site transfusion service.
Dr Menzies said other critical care services in Britain, Northern Europe and the United States already provided emergency blood and plasma at the scene.
“It's fantastic that we can now offer it here in Ireland for the first time,” he said.
Consultant haematologist at SVUH, Dr Joan Fitzgerald, said they had ensured that the on-site transfusion service was safe and that there was no wastage of blood products.
WWR, a declared National Ambulance Service asset, will carry red cells and two units of plasma to promote blood clotting.
Transfusing plasma in a 1:1 ratio with red cells is the best way to promote blood clotting.
When the blood is needed a portable unit, designed for out of hospital use, warms the intravenous fluids and blood products to body temperature in seconds.