The travel agent Flight Centre recently reported that, despite a gloomy economic outlook and fears for the Aussie dollar because of the European debt crisis, there had been double digit growth in travel to international destinations over the holiday period as Australians families take advantage of the strong Australian dollar and low airfares. This is good news for the travel industry and Australian families, but there is one other group to whom this may bring great benefit – those poised on the brink of having a potentially fatal sudden cardiac arrest (SCA).
Cardiac arrest occurs when the heart stops working suddenly, often in middle aged to elderly people, predominantly men, and frequently in those who have spent a good proportion of their life enjoying social activities such as smoking, which although feeling good at the time have repaid participants’ devotion with clogged arteries, broken lungs and high blood pressure. Even more cruelly, cardiac arrest can even occur in those who are innocent of such life choices, with rarer causes such as cardiac myopathy underlying collapses in the young and fit.
Whatever the causes, though, what happens is very similar in virtually all cases. The finely tuned electrical architecture of the heart, precisely constructed to produce and disseminate a perfectly organised electrical rhythm in a lifetime of 3 billion heartbeats, is suddenly disrupted by random, chaotic discharges. The loss of the orderly marching rhythm of the heart leaves a gulf that is quickly filled with the electrical anarchy of ventricular fibrillation (VF), causing the heart muscle to act like a writhing bag of worms rather than an efficient, tireless pump. The brain is the one organ which needs that oxygen more than any other part of the body; a lack of oxygen for more than 5 minutes will ensure that the SCA victim will not survive.
Given the size and geography of Australia, or even of its cities and towns alone, the likelihood that professional help in the form of paramedics, doctors or nurses reaching the SCA sufferer in less than 5 minutes is very small. Indeed, in 2007 the median emergency response time to a SCA by ambulance services around Australia was between 7.5 and 10 minutes, which is remarkably fast, however this is well outside the critical few minutes in which the victim’s life can be saved and leads to a survival rate, similar to most areas around the world, of between 5-10%. Each delay of one minute before treatment of SCA leads to 7-10% higher mortality, you can quickly see that a delay of 10-15 minutes means no survival at all.
There are however significant exceptions to this rule and this is where we came in. If you intend to have a cardiac arrest this week, you should make every attempt to be either at the Melbourne Cricket Ground watching a Big Bash League Twenty20 match, at the Crown Casino watching Reece Mastin or the Searchers, depending on your species of masochism, or ideally gazing at the departures board as your dream destination edges closer to the top of the screen.
Why is this?
There is good published evidence to show that survival from cardiac arrest in these locations is well above the average. The late Dr Jeff Wassertheil, a luminary of resuscitation in Australia, described how in 28 cardiac arrest patients at the MCG 24 (86%) left the venue alive and 20 (71%) were discharged home from hospital, after emergency first aid by St John Ambulance volunteers. In one series of cardiac arrests in casinos described in the New England Journal of Medicine, 53% of SCA sufferers survived to discharge from hospital, receiving their initial emergency treatment from casino security officers. In another series of cases the researchers compared the survival rate from SCA in their local casino to the rate in the surrounding community, and found them to be 65% and 5.5%. An observational study of responses to SCA patients at Logan airport in Boston showed a survival to discharge of 25%, and a another study conducted at O’Hare, Midway, and Meigs Field airports in Chicago showed a survival rate of 56%.
Even if you are not organised enough to have your SCA in the airport lounge, choosing the right destination may still elevate your chances of returning home with souvenirs and an overdraft. Wake County, North Carolina has an SCA survival rate of 41%; in Rochester, Minnesota 43% of SCA victims with VF survive and in beautiful Seattle the rate is over 50%.
But how can these differences exist? A study in Western Australia pointed us towards the reasons for these disparities, showing that unwitnessed SCA overall had a survival of 5%, but a paramedic witnessed SCA had survival of 33%. When only SCA with a chaotic VF rhythm were reviewed they showed the difference to be between 9% and 53%. Although we would hope that any cardiac arrest witnessed by paramedics would be managed effectively, the real discovery here is the importance of time in the response.
The Australian Resuscitation Council defines patients who collapse, are not breathing normally and who are unresponsive as being in cardiac arrest, and recommends two things which have been incontrovertibly shown to work. The first is immediate, continuous cardiopulmonary resuscitation (CPR), followed by defibrillation as soon as possible. Defibrillation? That sounds suspiciously like the ventricular fibrillation mentioned earlier which constitutes the fatal rhythm in many SCAs, and indeed it is. The fact is that a great proportion of SCA which occur in public places are immediately treatable with a great rate of success, and what they need is to have an immediate shock from a simple device which any lay person can apply, and which shocks the fibrillating heart to a momentary standstill, like erasing the scribbles with an Etch-A-Sketch, and allows it to recommence its regular, martial rhythm.
The success achieved by casinos, airports, and sports stadia have largely resulted from enlightened programs of placement of Automated External Defibrillators (AEDs), in the case of the airports in Chicago within “…a brisk 60 to 90 second walk…” apart. In Australia, Qantas led the way in 1991 with the implementation of defibrillators on aircraft, making travel to that dream destination safer, however otherwise we have not kept pace with developments that could be saving lives on a much more regular basis.
Studies have also shown that survival falls by 10-15% for each minute of cardiac arrest without CPR delivery, whereas bystander CPR initiated quickly after the onset of SCA has been shown to improve survival rates 2- to 3-fold. A study in Arizona showed that the rate of SCA survival was doubled if bystanders were taught to perform compression-only CPR (COCPR) where they did not have to do mouth-to-mouth, which has been demonstrated to severely limit the willingness to intervene to save lives in this way.
Associate Professor Paul Middleton is a specialist in emergency medicine. He is Chair of the NSW branch of the Australian Resuscitation Council and works as a Visiting Medical Officer in Emergency Departments of major hospitals in NSW and ACT.
He is Director of the Australian Institute for Clinical Education which teaches doctors and nurses how to treat serious illness and injury. He is the author of What To Do When Your Child Gets Sick, published by Allen and Unwin.