St John seeks to improve cardiac arrest outcomes

St John is trying to improve the outcomes for its cardiac arrest patients by focusing on factors that affect that chain of survival. Photo / File

Only 15 per cent of St John cardiac arrest patients survive the traumatic experience, the ambulance service says in a report published this morning.

But this compares favourably with similar ambulance services overseas, St John says.

"Of the 38 people who are treated for cardiac arrest by St John each week, 12 are successfully resuscitated and transported to hospital and six will later survive to be discharged."

The Wellington Free Ambulance service's cardiac arrest survival rate was 20 per cent in the same 12-month period covered by the 2014/15 Out-of-Hospital Cardiac Arrest annual report. Wellington Free is a much smaller service than St John and had only 199 cardiac arrest patients on which resuscitation was attempted, in contrast to St John's 1996.

"Numbers to survive a cardiac arrest are universally low," St John says.

"St John benchmarks itself against a number of ambulance services, including Ambulance Victoria in Australia and London Ambulance Service in the United Kingdom, both of which have 10 per cent survival rates."

"This is good news for New Zealanders and reflects on the skills of our ambulance officers and the quality of their care," says St John's medical director, Dr Tony Smith.

"It takes an entire system to save a patient in cardiac arrest, starting with community and bystander response, clinical control centres, New Zealand Fire Service and other co-responders, through to advanced life support from emergency ambulance service and hospital personnel," he says.

St John is trying to improve the outcomes for its cardiac arrest patients by focusing on factors that affect that chain of survival.

Bystanders need to start this chain, with immediate recognition of a cardiac arrest and the early application of CPR (cardio-pulmonary resuscitation) and defibrillation.

"For every minute without CPR or defibrillation, a patient's chance of survival falls by 10-15 per cent," says Dr Smith.

New Zealand has a low rate of public access to defibrillators.

The service's 2014/15 annual report on out-of-hospital cardiac arrest found that 64 per cent of its cardiac arrest patients received CPR from a bystander; only 4 per cent of patients received defibrillation from a public-access defibrillator.

The main cause of cardiac arrest was heart disease, the average age of patients was in the mid-60s, 67 per cent were male, 33 per cent were female, and Maori people had a 36 per cent higher incidence of cardiac arrest than non-Maori.