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Home > Consultancy > Public Access Defibrillation > Statistics
Public Access Defibrillation
– are we ignoring a vital component in the chain of survival for Cardiac
Arrest?
Statistics from the Irish Heart Association show that in the year 2000 approx 40% of all deaths in Ireland were due to cardiovascular disease. Of this category, half were due to coronary heart disease (heart attack). This equates to 6000 people, or 16 people per day dying from a heart attack.
The incidence of heart attacks is higher in the over 65-age group but is by no means exclusive to this group. In fact Irish men and women have the highest rate of death before the age of 65 from coronary heart disease in the European Union. Currently about 11% of the population are aged over 65 years. By 2026 it is projected that 18% of the population will be over 65 and therefore the burden of coronary heart disease will have implications for resources and services in both primary care and hospital sector.
Cardiac arrest is the sudden, abrupt loss of heart function. The victim may or may not have diagnosed heart disease. Sudden death occurs within minutes after symptoms appear. The most common underlying reason for people to die suddenly from cardiac arrest is coronary heart disease. Most cardiac arrests that lead to sudden death occur when the electrical impulses in the heart become chaotic (ventricular fibrillation). Other factors besides heart disease and heart attack can cause cardiac arrest. They include respiratory arrest, electrocution, drowning, choking and trauma.
In over 70-90% of all cardiac arrest cases ventricular fibrillation is present in the heart. This rhythm causes a quivering of the heart making it "wobble" like jelly rather than pumping effectively. Ventricular fibrillation can be reversed if it's treated within a few minutes with an electric shock to the heart to restore a normal heartbeat. These shocks stun the heart, allowing the heart's natural pacemaker a chance to restore a normal heart rhythm. This process is called defibrillation. CPR (Cardiopulmonary Resuscitation) alone cannot reverse this abnormal heart rhythm. CPR, which consists of mouth-to-mouth rescue breathing and chest compressions, is only a "holding technique", keeping the brain and heart alive until a defibrillator arrives. A victim's chances of survival are reduced by 7 to 10 percent with every minute that passes without defibrillation. Few attempts at resuscitation succeed after 10 minutes.
In-hospital survival after cardiac arrest in heart attack patients improved dramatically when the defibrillator and bedside monitoring were developed. Later it also became clear that cardiac arrest could be reversed outside a hospital by properly staffed emergency rescue teams trained to give CPR and to defibrillate. Thus, the problem isn’t the ability to reverse cardiac arrest, but reaching the victim in time to do so. As a consequence of these facts, there is now a move to bring one of the most important lifesaving techniques into the public domain within minutes of potential cardiac arrest victims. This is the concept of having Public Access Defibrillation (PAD) schemes in places such as shopping centres, golf clubs, airports etc. Public Access Defibrillation involves the use of Automated External Defibrillators by trained members of the public.
An Automated External Defibrillator (AED) is a computerised device, which will analyse the heart rhythm of a person in cardiac arrest and can recognise a shockable rhythm. The computerised system can then advise the operator whether the rhythm should be shocked. If used within minutes of an arrest, the chances of survival are markedly improved. AED training for lay rescuers teaches the basic adult CPR techniques and how to use an AED.
Statistics from the American Heart Association estimate that more than 95 percent of cardiac arrest victims die before reaching the hospital. In cities where defibrillation is provided within 5 to 7 minutes, the survival rate from sudden cardiac arrest is as high as 49 percent. In one PAD program initiated by two Chicago airports (O'Hare and Midway), 75% survival rates among patients with ventricular fibrillation were reported among 14 patients in the first 10 months of the program.
In contrast, Irish statistics indicate that only 1% of cardiac arrest victims survive. It is clear that Public Access Defibrillation schemes should be getting more encouragement. Both Blanchardstown Shopping Centre and Dublin Airport already have Public Access Defibrillation schemes in place, but we have a long way to go before the penetration of such schemes into the public domain reaches the level required to ensure access to defibrillators by victims of cardiac arrest within 5 minutes.
Early CPR and rapid defibrillation combined with early advanced care can result in high long-term survival rates for witnessed cardiac arrest. If bystander CPR was initiated more consistently and if AEDs were more widely available, a significant number of lives could be saved each year. Death from sudden cardiac arrest is not inevitable. If more people react quickly by calling 999 and performing CPR, more lives can be saved.