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Cardiac arrest outside hospital is a common mode of unexpected death
in our society. The arrest is usually caused by coronary
artery disease, and indeed may be its first manifestation, occurring
in apparently fit and well individuals. The causative arrhythmia is
usually ventricular fibrillation, but by the time help arrives and
the rhythm is recorded it has often degenerated into asystole.
In this issue of the Journal, Meyer et al1 present a
detailed medical perspective of this problem, and outline the steps
we need to take to improve the survival rate for victims of
out-of-hospital cardiac arrest, particularly the "chain of
survival" -- the critical links in the resuscitation process. When a
cardiac arrest is witnessed, the first priority is defibrillation,
but in most situations cardiopulmonary resuscitation (CPR) needs be
undertaken before defibrillation.
The spectacular success of implantable defibrillators in
terminating lethal arrhythmias2 in patients known to be at
extreme risk of ventricular fibrillation raised the possibility
that the same sensing technology and defibrillator waveforms might
be incorporated into an external defibrillator, without the need for
rhythm interpretation by a medical or paramedical attendant. Such
devices were introduced over 10 years ago, and have been widely
implemented, with results for successful defibrillation by junior
ambulance officers that were as good as those of
paramedics.3 By 1990, the New South Wales
Ambulance Service had introduced semiautomatic defibrillators
into all its frontline ambulances (ie, those not used for routine
transport) to complement the care given by paramedics with manual
defibrillators. Similar systems have since been initiated in other
Australian States.
By 1991, the concept of public access defibrillation (PAD) was
re-emerging. This idea was first conceived by the pioneer of
prehospital coronary care, Frank Pantridge of Belfast,4 who developed a
small but primitive defibrillator in the late 1960s which could be
installed next to every fire extinguisher and used in the same way,
simply and easily, and by whoever was closest. Pantridge asked the
question "Is property more important than life?". With the
re-emergence of this concept within the American Heart Association,
the aim was to have semiautomatic defibrillators so widely
available, and sufficient members of the public trained, that a
person who suffered a cardiac arrest in a public place might have the
benefit of a defibrillator before the arrival of an ambulance and when
the chance of a successful outcome may be well over, rather than well
under, 50%.5
Semiautomatic defibrillators are now deployed in what may seem to be
the most unlikely places,5 and Australia has played a
leading role. They were first installed in the QANTAS International
fleet and in Australian airports during 1991.6 The long-term survival rate
for people treated on the ground or in the air by QANTAS International
staff is 32%,7 now exceeded by the seven of
14 (50%) for people treated by American Airlines staff over the past 18
months.8
Defibrillators are deployed widely in Chicago's O'Hare Airport and
are available for public access. Deployment of public access
defibrillators in airports is becoming commonplace, and Sydney's
international and domestic terminals will be equipped with a system
similar to Chicago's within months. Installation in airliners is
becoming the industry standard throughout the world,8 with programs
completed or under way for most major international and domestic
airlines (including QANTAS and Ansett Domestic).
Use in airports and airliners has followed awareness of the fact that
deaths from cardiac arrest in the air are far more common than deaths
from aircraft crashes,7,8 while deaths in terminals
of people undergoing unaccustomed exercise are more common than at
other locations9 (except at sporting venues,
where deaths in older spectators are common). Survival rates of 70%
have been reported from the Melbourne Cricket Ground10 and in Las
Vegas casinos:11 in both situations remote
monitoring of crowd activity enables quick recognition, which,
together with appropriate placement of personnel and devices,
ensures a prompt response. Deployment of defibrillators in police
cars, complementing the ambulance service in the environs of the Mayo
Clinic, has increased community survival after cardiac arrest in
Rochester, Minnesota, to near 50%.12
St John Ambulance, as the leading teacher of community resuscitation
and first aid in Australia, has endorsed training in defibrillation
with CPR, and is embarking on an ambitious program, through its
training and operational arms, to make public access defibrillation
widely available throughout the nation. Such a program must mesh with
the existing professional ambulance service, and complement this by
strengthening that most important earliest link in the "chain of
survival" -- the prompt reversal of ventricular fibrillation by
whoever can do so first, and fastest.
In strife-torn Belfast, Pantridge's idea lapsed because no system
was available at the time for automatic recognition of ventricular
defibrillation, so the device had to be used in the manual mode, and
could have been used as a weapon. The introduction of safe
semiautomatic defibrillators which will only operate in the
presence of ventricular fibrillation has changed this situation. A
satisfactory answer can now be given to Pantridge's question. As
peace emerges in Ulster, the concept proposed by Pantridge and
Geddes4 has taken firm root
throughout the whole world.
Michael F O'Rourke
Professor of Medicine
University of New South Wales
and
St Vincent's Hospital and Clinic, Sydney, NSW
- Meyer ADMcR, Cameron PA, Smith KL, McNeil JJ. Out-of-hospital
cardiac arrest. Med J Aust 2000; 172: 73-76.
-
Moss AJ, Hall WJ, Cannon DS, et al. Improved survival with an
implanted defibrillator in patients with coronary disease at high
risk for ventricular arrhythmia. N Engl J Med 1996; 335:
1933-1940.
-
O'Rourke MF, Hall J. Pre-hospital cardiac arrest in New South Wales
(1992). Aust N Z J Med 1994; 24: 619.
-
Geddes JS, editor. The management of the acute coronary attack: the
J Frank Pantridge Festschrift. London: Academic Press, 1986.
-
Nichol G, Hallstrom AP, Kerber R, et al. American Heart Association
Report on the Second Public Access Defibrillation Conference, April
17-19, 1997. Circulation 1998; 97: 1309-1314.
-
Donaldson E, O'Rourke MF. Defibrillators on QANTAS aircraft.
Med J Aust 1992; 156: 293.
-
O'Rourke MF, Donaldson E, Geddes JS. An airline cardiac arrest
program. Circulation 1997; 96: 2849-2853.
-
Crewdson J. Code blue: survival in the sky. Chicago Tribune
Aug 1, 1999: C1-C3.
-
Becker L, Eisenberg M, Fahrenbruch C, Cobb L. Public locations of
cardiac arrest: implication for public access defibrillation.
Circulation 1998; 97: 2106-2109.
-
Wassertheil J, Keane G, Fisher N, Leditschke JF. Cardiac arrest
outcomes at the Melbourne Cricket Ground and Shrine of Remembrance
using a tiered response strategy -- a forerunner to Public Access
Defibrillation. Resuscitation 2000. In press.
-
Valenzuela TD, Bjerke HS, Clark LL, et al. Rapid defibrillation by
non-traditional responders. The Casino project. Acad Emerg
Med 1998; 5: 414-415.
-
White RD, Hankins DG, Bugliosi TF. Seven years' experience with
early defibrillation by police and paramedics in an emergency
medical services system. Resuscitation 1998; 30: 145-151.
©MJA 2000
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