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Cardiac Arrest in Medical and Dental Practices
Implications for Automated External Defibrillators
Linda Becker, MA;
Mickey Eisenberg, MD, PhD;
Carol Fahrenbruch, MSPH;
Leonard Cobb, MD
Arch Intern Med. 2001;161:1509-1512.
ABSTRACT
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Background To determine the need for placing automated external defibrillators
(AEDs) in medical and dental practices, we identified cardiac arrests at these
locations.
Methods Locations of cardiac arrest were abstracted from Emergency Medical Services
data from January 1, 1990, through December 31, 1996. We calculated the annual
incidence of cardiac arrest per type of practice.
Results There were 142 cardiac arrests in medical or dental practices. Dialysis
centers had a relatively high incidence of cardiac arrest ( 0.746 per practice
annually). Cardiology, internal and family medicine, and urgent care centers
had a medium incidence (0.01 per practice annually). All other medical
and dental practices had a low incidence ( 0.002 annually).
Conclusions Placement of 779 AEDs in the high- and medium-incidence practices would
have provided treatment for 112 patients with cardiac arrest in 7 years. To
provide for the 16 cardiac arrests in low-incidence practices, an additional
1928 AEDs would be required.
INTRODUCTION
A PHYSICIAN'S office, particularly a practice seeing older adults or
patients with recognized heart disease, would seem a logical place to locate
an automated external defibrillator (AED). An on-site AED would allow immediate
defibrillation for patients in whom ventricular fibrillation (VF) develops,
thus saving the minutes normally required for emergency medical services (EMS)
personnel to arrive. We undertook a study to determine the incidence of cardiac
arrest in community medical and dental practices, and to investigate the potential
benefit of placing AEDs there.
SUBJECTS AND METHODS
The study took place in Seattle and King County, Washington (combined
population, 1.5 million in the 1990 census). The first EMS unit arriving for
a cardiac arrest is usually a fire department vehicle, staffed by emergency
medical technicians trained to use automated or manual defibrillators. Paramedics
arrive several minutes later to provide advanced life support.1-2
We performed a retrospective record review of EMS run reports from January
1, 1990, through December 31, 1996. A case was defined
as a patient having cardiac arrest at a community medical or dental practice
and for whom defibrillation or cardiopulmonary resuscitation (CPR) was performed
by EMS or professional office personnel. All cases of cardiac arrest with
location marked "clinic/doctor's office" were reviewed, as well as those marked
"public indoors" or "public outdoors." The address of each was looked up to
determine whether it was a medical practice, and if so, what type. The cardiac
arrests were due to presumed heart disease or other medical cause. Not included
were 11 patients who were revived by a physician's staff using CPR only. Since
patient contact was not required and no copies of medical records were needed,
permission was not required from the institutional review board.
We recorded type of practice, age, sex, apparent reason for the visit,
symptoms before arrest, first identified rhythm after collapse, whether collapse
was witnessed by bystanders or EMS personnel, defibrillation before arrival
of EMS, cause of the arrest (based on the EMS report, hospital data, and death
certificate information), and outcome (death or discharge alive).
We included medical or dental practices outside hospitals. A practice
was defined as 1 or more physicians (doctors of medicine or osteopathy) or
dentists who used a common waiting area and registration desk. The arrests
took place anywhere inside or outside the building. We included urgent care
clinics and dialysis centers, which we identified through telephone book listings
and verified by calling. We excluded nursing homes, residential rehabilitation
centers, and ambulatory surgery clinics. Also excluded were practices of pediatricians,
pathologists, and hospital-based physicians such as emergency physicians and
anesthesiologists. Alternative practices (homeopathy, naturopathy, acupuncture,
and chiropractic) were not considered, because we identified no cardiac arrests
in these settings.
Based on King County Medical Society data from the year 1998, there
were 2044 physician members in 1235 practices. The medical society estimates
that about one third of physicians in the county are not members. Therefore
we adjusted the number of physicians upward by 50%, resulting in an estimated
3066 physicians in 1853 practices. We then adjusted the numbers downward to
reflect the 8% fewer physicians in 1995 than in 1998, based on data from the
Washington State Department of Licensing, Seattle. We used a list provided
by the medical society of physicians sorted by address to count the number
of practices. In 1995 there were an estimated 2821 physicians in 1705 practices.
The numbers of dentists and dental practices were obtained from 1998 listings
of the Washington State Dental Association, Seattle. Using the same methods
as with the medical society, we estimated there were 1249 dentists in 976
practices.
We grouped practice types where cardiac arrest occurred into the following
6 categories according to frequency of occurrence: dialysis centers, cardiology
practices, urgent care centers, family and internal medicine practices (including
general practice and internal medicine specialties other than cardiology),
all other medical specialties (dermatology, neurology, obstetrics and gynecology,
occupational medicine, ophthalmology, otolaryngology, physical medicine and
rehabilitation, radiology, psychiatry, surgery and surgery specialties, and
urology), and dental practices. Simple arithmetic was used to calculate an
incidence of cardiac arrest for each practice type.
RESULTS
A total of 8088 nontraumatic arrests occurred in Seattle and King County
during the study period. Of these, 142 (2%) were associated with medical and
dental practices. Table 1 shows
the characteristics and outcomes of cardiac arrests compared with those in
other public locations and in homes. Overall survival and survival of VF were
highest in medical and dental practices. A physician or a nurse administered
defibrillation to 16 patients. Six (38%) of the 16 had converted from VF to
a normal sinus rhythm on arrival of EMS, and 9 (56%) of the 16 survived to
hospital discharge. This is comparable to a survival rate of 45% in the 64
patients who were administered defibrillation initially by EMS. We could not
obtain survival data for 1 patient.
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Table 1. Characteristics of Cardiac Arrests in Medical and Dental Practices,
Other Public Locations, and at Home*
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Table 2 shows estimates
of the incidence per practice and the number of practices in each type to
yield 1 cardiac arrest per year. For all types of practices taken together,
the annual incidence was 0.008, or 1 cardiac arrest per year for every 133
physicians' and dentists' practices. Dialysis centers had the highest annual
incidence, with approximately 1 cardiac arrest per year among the 9 centers
collectively. Cardiology practices, urgent care clinics, and family practice
and internal medicine practices had a minimum incidence. All other medical
and dental practices had a low incidence of cardiac arrest. There were a total
of 16 cardiac arrests annually in the combined 779 high- and medium-incidence
locations, or 1 cardiac arrest per 48 sites. There were 2.28 cardiac arrests
annually in the 1928 sites with a low incidence, or 1 cardiac arrest per 845
sites.
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Table 2. Incidence of Cardiac Arrest by Type of Practice
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The reason for the visit could be determined for 117 patients (82%).
Renal dialysis was the most frequently cited (47 patients). Thirty-eight patients
were described as having cardiac symptoms before the visit. Twenty-six patients
were visiting the physician for medical therapy or tests and 6 were visiting
a dentist for dental care. Twenty-two patients were visiting for reasons that
could not be determined from the report and 3 were employees (a physician,
a nurse, and a worker at a loading dock).
COMMENT
With the exception of the dialysis centers, the incidence of cardiac
arrest in medical and dental practices was considerably lower than that in
other higher-incidence public locations, which had annual incidences ranging
from 0.03 to 7.00.3 Cardiac arrests in community
medical and dental practices and in other public locations have higher rates
of witnessed cardiac arrest and bystander CPR than those occurring at home.
As described previously,4 patients with cardiac
arrests in public have higher rates of survival of VF than those with arrests
at home. This increased survival is probably the result in part of higher
rates of bystander CPR.
We chose to study practices rather than individual physicians and dentists
because we assumed that physicians within a practice would share a relatively
expensive and infrequently used item such as an AED. Had we used the total
number of physicians and dentists practicing as the denominator, the rates
of cardiac arrest per physician would be considerably smaller than the rates
per practice. For example, there were 55 cardiologists in 35 practices; our
calculated rate of 0.06 annually per practice would be 0.03 annually per physician.
Our data support the placement of AEDs in dialysis centers. We presented
these data to the local dialysis centers, and all agreed to equip their centers
and train their staffs in the use of AEDs. Among the 9 dialysis centers, 20
(43%) of the 47 cardiac arrests took place in the busiest center, but the
remainder were evenly distributed among the other centers. The data also support
consideration of defibrillator placement in cardiology practices, urgent care
centers, and internal medicine and family practice settings. It would appear
there are too few cardiac arrests in dental practices and other medical specialties
to justify their routine placement at this time.
A potential limitation of the study is the difficulty of determining
the exact number of physicians and dentists and practices. Our estimates involve
extrapolations based on historical trends and membership percentages in the
medical and dental societies. Therefore, the calculated incidences of cardiac
arrest in the various practices are only as accurate as the assumptions about
the numbers of practices. However, we believe that the relative order of magnitude
is accurate.
Failure to identify a cardiac arrest in medical and dental practices
could result in underreporting and therefore a lower estimate of the number
of AEDs required. The occurrence of this was probably minimal, however, since
all cases of cardiac arrest for which EMS is summoned are received and reviewed
in our office, and all were evaluated for location of the event.
This is not an intervention study and cannot address whether and to
what extent placement of AEDs in physicians' practices will improve survival,
but rather a descriptive study attempting to provide information for the rational
placement of AEDs based on cardiac arrest data. Although a cost-effectiveness
analysis is beyond the scope of this study, we can make some estimates. If
we assume an AED costs $3000 and has a useful life of 10 years, the AED cost
is $300 per year. Placing an AED in the 779 high- and medium-incidence locations
in our community would cost $233 700 annually. We observed 16 cardiac
arrests annually in these locations. Using numbers from Table 1, 9 locations (56%) would have VF as the initially monitored
rhythm. Using a discharge rate of 56% (the percentage of VF survivors who
received defibrillation by medical practice personnel) we would expect 5 discharges
annually, or $46 700 per life saved. This estimate does not take into
account life expectancy. If the survivors were to live 5 additional years,
the cost per year of life would fall to $9300.
Our analysis does not include an attributable benefit of practice-based
AEDs compared with the existing EMS system. Of the many factors that may influence
the need for AEDs, our study considers only the location and incidence of
cardiac arrest. Other factors to consider are the quality and location of
EMS, the response times, and the community survival rate. In many urban communities,
the rate of survival of VF is currently less than 5%.5-6
Clearly, every minute saved from time of collapse to defibrillation will improve
survival.
Training and upkeep on hundreds of AEDs are not insignificant. An AED
located within a medical practice might be used only once in many years, and
yet regular training and maintenance must be performed. It is for simplifying
training and because of infrequent use that our study focuses on AEDs as opposed
to traditional defibrillators. The latter are more costly and require rhythm
recognition by staff, which includes not only physicians and nurses but also
technicians and even parking lot attendants. The AEDs would seem more suitable
for this purpose.
Our study demonstrates that medical practices can be divided into locations
of high, medium, and low incidence of cardiac arrest. The frequency of cardiac
arrest by type of practice in the community should guide the placement of
AEDs.
AUTHOR INFORMATION
Accepted for publication October 31, 2000.
We thank Janine Johnson of the King County Medical Society and Patti
Brackin of the Washington State Dental Association, Seattle, for providing
data.
Corresponding author and reprints: Linda Becker, MA, Emergency Medical
Services Division, 999 Third Ave, Suite 700, Seattle, WA 98104 (e-mail: linda.becker{at}metrokc.gov).
From the Emergency Medical Services Division, Seattle–King County
Department of Public Health (Ms Becker and Dr Eisenberg), and the Department
of Medicine, University of Washington (Drs Eisenberg and Cobb and Ms Fahrenbruch),
Seattle, Wash.
REFERENCES
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1. Cobb LA, Fahrenbruch C, Walsh TR, et al. Influence of cardiopulmonary resuscitation prior to defibrillation
in patients with out-of-hospital ventricular fibrillation. JAMA. 1999;281:1182-1188.
FREE FULL TEXT
2. Hearne TR, Cummins RO, Goy JJ, Fromer M, Kappenberger L. Improved survival from cardiac arrest in the community. Pacing Clin Electrophysiol. 1988;11:1968-1973.
PUBMED
3. Becker L, Eisenberg M, Fahrenbruch C, Cobb L. Public locations of cardiac arrest: implications for public access
defibrillation. Circulation. 1998;97:2106-2109.
FREE FULL TEXT
4. Litwin PE, Eisenberg MS, Hallstrom AP, Cummins RO. The location of collapse and its effect on survival from cardiac arrest. Ann Emerg Med. 1987;16:787-791.
FULL TEXT
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5. Becker LB, Ostrander MP, Barrett J, Kondos GT. Outcome of CPR in a large metropolitan area: where are the survivors? Ann Emerg Med. 1991;20:355-361.
FULL TEXT
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ISI
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6. Lombardi G, Gallagher J, Gennis P. Outcome of out-of-hospital cardiac arrest in New York City: the Pre-Hospital
Arrest Survival Evaluation (PHASE) Study. JAMA. 1994;271:678-683.
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