An evaluation of the Public Access Defibrillation (PAD) Demonstration

4.3 Effectiveness of the PAD Demonstration

Page last updated: August 2008

When it came to commenting on the effectiveness of the PAD Demonstration in improving patient outcomes from cardiac arrest, a number of stakeholders stated that it was important to consider the original aim of the program first. The project was intended to 'test the water' regarding acceptance of AEDs in the Australian community. It was set up as a trial, with only a limited number of devices funded and installed at sites around the country.

The program was a concept where we thought there should be defibrillators available in the community. We took it to a level to test the water – Are they acceptable? Will people use them? The aim was really to work out the extent to which these things would be used. (Stakeholder)
In this context, Stakeholders were cautious when commenting on the effectiveness of the current PAD Demonstration in terms of improved patient outcomes and, more specifically, in identifying a causal relationship to a reduction in mortality rates from sudden cardiac arrest. With only one third (approximately 30%) of sudden cardiac arrest events occurring in public areas, stakeholders reported that it was difficult to judge whether the PAD Demonstration had improved survival rates from cardiac arrest in Australia on a larger scale.

We were never going to see improvements in increased survival [from this trial]. (Stakeholder)

You couldn't say that PAD has made a difference to mortality from sudden cardiac arrest in Australia, because such a small number happen in public places. But you could say that it has provided a more capable response. (Stakeholder)

However, stakeholders were very keen to emphasise that placements of AEDs under the PAD Demonstration had saved some lives and improved patient outcomes for a number of individuals.

Overall, the PAD trial could be judged as effective in providing a capable response to sudden cardiac arrest in public areas, in demonstrating that organisations were willing to accept AEDs and that the devices would be used appropriately when sudden cardiac arrest events occur.

When asked how PAD could impact on survival rates from cardiac arrest in Australia, Stakeholders drew comparison to the evolution of public access to defibrillation in the US. A combination of federal and state government funding, public advocacy and state and national regulation has assisted the US to evolve to a stage where it was considered a liability not to install AEDs.

It has gotten to the point in the US, where owners of buildings can be found negligent for NOT having an AED on site. Over there AEDs are seen as part of public safety. (Stakeholder)
Some stakeholders felt that the current Australian PAD trial had used similar guidelines to US, setting a solid foundation that could eventually translate into a broader saturation of AEDs. Others noted that the level of saturation needed for effective response to sudden cardiac arrest in Australia was a long way off, as Australia was yet to go down the path of regulation or large scale public awareness campaigns. A level of saturation of AEDs was required for early access defibrillation to impact on survival rates from cardiac arrest.

The question will come down to what is a reasonable standard of care. It will get to the stage that a person collapses and no if defibrillator is available that organisations will be held liable. (Stakeholder)

There has to be a saturation process but we are way off saturation here. Less than 10% I would say. (Stakeholder)

Case Study – Early Defibrillation at the MCG

Stakeholders frequently mentioned the rapid response early access defibrillation trial at the Melbourne Cricket Ground as being one of the most effective models. Generally, stakeholders believed that public access to defibrillation produced a three fold increase in the rate of survival from sudden cardiac arrest.

The trial of a three tiered response model implemented at the MCG was reported to have resulted in a 71% survival rate from cardiac arrest at the stadium (86% survived to ambulance handover) – compared with a 3% survival rate from out-of-hospital resuscitation reported at the same time.18 The survival rate of 71% was also believed by stakeholders to be several times higher than pure PAD programs.

The three tiers of response at the MCG consisted of:
  1. A central location notified of a collapse by radio communication
  2. Mobile defibrillation teams would then respond to the incident within 1-2 minutes and administer defibrillation (using older mobile defibrillators in the first instances, AEDs once that technology had advanced)
  3. Medical personnel formed the third tier – that is a nurse or a doctor would arrive on the scene to provide follow up treatment until hand over to the ambulance.
This tiered defibrillation model was tailor made for the venue, and ensured for the delivery of prompt CPR, timely defibrillation and advanced life support.

18 Wassertheil, Keane, Fisher, Leditchke. Cardiac arrest outcomes at the Melbourne Cricket Ground and Shrine of Remembrance using a tiered response strategy. Resuscitation 2000; 44: 97-104