ELCARE’S CRYSTAL BALL – A VISION FOR THE FUTURE
(Condensed from a lecture given November 2000 at Texas College of Osteopathic Medicine)
I’m Elroy Cantrell, DO, PhD, an emergency physician for the past 15 years. Prior to that
I was the chairman of the Pharmacology department at the Texas College of Osteopathic
Medicine in Fort Worth.
THE PROBLEM: I have had occasion to treat numerous cases of cardiac arrest and
have observed a considerable variation in the quality of care provided by emergency
technicians and paramedics in rural Texas. I have also recognized several shortcomings
in the pharmacologic and technical management of cardiac arrest. The American Heart
Association has encouraged an intense program of basic life support training in the US,
and expanded use of automatic electrical defibrillators – yet the rate of rescues and
resuscitation from sudden cardiac death is still dismal. The survival rate varies from
under 1% in large cities with limited CPR training, high-rise apartments & traffic
congestion, up to 15% in Seattle, Washington where an aggressive CPR training program
and enhanced Emergency services has been implemented. Texas has about 4-5%
THE HOPE: Recent research in resuscitation indicates that survival from sudden cardiac
death can be markedly improved with implementation of existing technologic
innovations. Furthermore, new devices under development can contribute to this
expectation of improved survival and improved quality of life. —- So how does the
new paradigm work ?
THE NOW: Sudden cardiac death is a major health problem in the US and the world.
The American Heart Association reports that about 350,000 persons in the USA
experience cardiac arrest (sudden cardiac death) each year. Unfortunately, even under
the best circumstances of outpatient emergency care, MOST DIE ANYWAY. Only 1-
15% survive, depending upon regional resources and training. Much more can be done
to improve these numbers.
The American Heart Association states that there is a decline in survivability of 10% for
each minute that electrical defibrillation is delayed. According to Dr. Paul Pepe of
Southwestern Medical School in Dallas, the supporting data is actually pooled from cases
with and without CPR. The original data from the three studies show that without any
CPR, death is virtually assured if defibrillation is delayed for as little as five or six
minutes. In contrast, one can expect some success with defibrillation within 20 minutes
— if PROMPT CPR is provided !
The current guidelines for cardiac life support are published in many training manuals for
CPR. The American Heart Association describes and recommends the sequence of the
“Chain of Survival” which includes:
1) Recognize the problem and call for help,
2) start CPR,
3) Electrical defibrillation at the earliest possible time, and
4) Advanced life support efforts.
Or, in short : Provide CPR —– Prompt defibrillation —– and if not successful do not
pursue a futile effort.
We know that the best blood circulation is obtained with a healthy, beating heart. The
second best with a sick, but beating heart. Third best is perfect CPR, even though that
can sustain life for only a few minutes as we now understand and provide CPR. Fourth
best is a tie between poor CPR and doing nothing. With our present understanding, the
bottom line is clear – Without a functional heart, survival is not possible.
But is that really true ???
THERE’S MORE ? Recent research in resuscitation suggests that with the present
paradigm of care we may be doing – – –
During the past several years reports of aggressive management with early application of
heart-lung bypass (San Diego, Detroit, Philadelphia, Japan, and other sites) indicate
markedly improved physiologic and neurologic survival even after 30+ minutes of arrest
and failure of electrical defibrillation and conventional efforts.
These results are consistent with the notion that a contractured, oxygen-starved heart can
actually become an obstruction to passive flow of blood during sustained CPR.
We and others envision a new paradigm of resuscitation evolving over the next few
years. The primary emphasis will be toward support of brain function and other vital
organs. Less emphasis will be toward restoring a heartbeat but overall rescue efforts will
As before, immediate and PERFECT CPR must be provided. And, as before, electrical
defibrillation is provided as soon as possible. Most times a normal rhythm deteriorates to
ventricular fibrillation (VF) or Ventricular tachycardia (VT) or a state of pulseless
electrical activity (PEA), also called electromechanical dissociation (EMD). Finally, a
state of asystole evolves where no electrical activity can be detected. The current
guidelines of the American Heart Association indicate that one should consider early
termination of rescue effort when asystole is seen. — But we shouldn’t give up !
There are obvious benefits to advanced efforts to manage this “stunning” effect on the
heart with advanced care, including heart-lung support to allow time for the heart to be
“serviced” or replaced.
NO KIDDING ! If we can truly manage shock and support viability in vital organs, we
can expect substantial improvement in outcomes.
If we expand the delivery of prompt CPR and advanced care, then the technology
is certainly available (or on the horizon) for sophisticated interventions which
could improve length and quality of life. These include improved heart-lung
devices, artificial hearts, xenobiotic (animal) hearts, and lab-grown human hearts.
TA DA ! Such measures are now available or in final stages of development.
Following Cardiac Arrest there is a brief window of opportunity to provide definitive
treatment and re-establish pump function. With no external support (CPR) a few persons
have been resuscitated spontaneously, by coughing , or with precordial thump.
Application of electric defibrillation within a 4-5 minute window can be lifesaving.
Survivability otherwise is grim. Early application of basic and advanced CPR can
double the time of the window of opportunity and increase probability of survival with
intact neurologic function. Extensive community training in prompt application of CPR
and defibrillation has increased survival (as in Seattle, Washington) to about 15%.
A study of recent reports of early use of heart-lung bypass in cardiac arrest indicates that
survivability can be improved greatly if applied within 30 minutes following arrest – even
after CPR and defibrillation failed. Several hours on bypass allowed time for surgical
intervention and recovery of the “Stunned” heart in some cases. Furthermore, many of
the non-survivors would have benefited from replacement of the heart with a new
biologic or mechanical pump.
There is a latin term “SINE QUA NON” which means “without which there is
nothing”. There is a part of the scheme which clearly fits that term — Perfect and
YES, in cardiac arrest the first critical element in survival is perfect and sustained CPR
until the heart can be re-started (defibrillated) or an adequate substitute can be provided
OUCH ! Unfortunately, barehanded CPR rarely provides the quality of CPR we seek,
and may even cause further injury to a victim if improperly performed.
Broken ribs and internal organ damage may result from improper or excessively applied
force. Inadequate circulation may result from too little applied force.
Recent reports from the medical literature indicate that device-assisted CPR could
markedly improve performance by CPR providers. Presently only one device is
approved by the FDA for basic CPR —CPRplus — and only one device for advanced CPR
—The Thumper. Other devices have been invented, but all are still pending FDA
approval. The studies reported with these are impressive.
Several other devices have been invented to assist providers of CPR. A few of the most
recent devices are described here. BASIC CPR assist devices rely on human strength
and endurance to power the effort.
The CPRplus is the only “new” CPR device ever approved by the FDA. It has been on
the market about 5 years. A pressure display gauge is attached to a bellows chamber
which is placed on the lower sternum. This device monitors applied force and helps the
rescuer provide adequate force while minimizing hazardous excessive force on the chest.
A metronome in the carrying case paces the rhythm.
The Cardiopump was devised after a report in the San Francisco Examiner in 1989. A
bystander applied push-pull force to the arrest victim’s chest with a plumber’s plunger.
The victim was subsequently resuscitated. The theory of its advantage is that lifting the
anterior chest wall enhances blood return to the heart. Although not approved in the
USA, it has been employed in Europe and Australia. The device requires 15% additional
energy to operate and tires the rescuer more rapidly.
Lifestick exploits the reported advantage of abdominal counterpulsation to enhance
blood return to the chest. The two legpads are applied to the chest and abdomen and a
“See-Saw” rhythm is applied. Since the abdominal stroke also forces blood toward the
head, the effective stroke rate is doubled and blood flow to the brain is increased. This
device is thought to require less energy by the rescuer, as well. This device has not yet
been approved by the FDA.
We have reported results of our own basic CPR device “The Grip” and the
improvement in CPR performance by paramedics is remarkable. Our studies in
experimental pigs indicate 50-80 % of normal blood flow to the brain can be expected
with “The Grip”.
The disposable chestpad is imprinted with brief reminders of the current parameters of
basic CPR. (You OK? – Call help – Check pulse – 2 breaths), and the 2:15 breath-to-
strokes ratio for single rescuer vs 1:5 ratio for two rescuer CPR.
Notches at the ends of the chestpad help to align with the xyphoid process and the
sternum. A peel-off backing exposes sticky adhesive to affix the pad to the bare chest.
There is no danger of misplacing or moving the device after being properly applied.
A handgrip allows for firm control of the device and allows the entire palm and hand to
remain in a comfortable position during the rescue. Below the handgrip is the basepiece
with a force transducer and microswitches.
The display module contains a light and speaker to provide visual and audible output
from the metronome timer. A rate selector allows one to proceed at 80 or 100 strokes per
minute. The stroke counter window displays the cumulative strokes up to a preselected
count of 5 or 15 counts, then a chirp is provided to remind the rescuer to give rescue
breaths. A unique feature is the tilt monitor. One of four microswitches in the base may
be triggered if force is not applied straight down onto the sternum, one of the four L.E.D.
lamps points in the direction of misapplied force.
With instant feedback of performance corrections in rate, force and direction can be
made “on the fly”. To further improve performance, we suggest abdominal binding
Consistent with recent studies by others, we found that CPR performance was
substantially augmented with our device.
Six persons from the Fairfield, Texas EMS were tested on a recording Resusci-Anne
employing conventional bare-hand compressions as taught by The American Heart
Association, and with our performance assist device.
Persons were tested both on the floor of the ambulance barn and in a moving ambulance
to simulate a rapid trip to the hospital.
The percentage of “adequate” strokes per minute was surprisingly variable among these
persons, when bare-hand technique was used, but the device which provided stroke-to-
stroke feedback on performance allowed all but one rescuers to maintain or reach near-
perfect performance even when pitching around in the back of a moving ambulance.
POWERED CPR DEVICES are intended for sustained rescue efforts, and relieve the
rescuer of his own physical effort. Furthermore, stroke-to stroke variability may be less.
The Thumper has been sold in the USA for about 30 years. It was marketed prior to the
date FDA assumed authority over new medical devices. The pneumatically powered
device uses the oxygen supply bottle to power a piston in the arm of the unit, providing a
preset stroke distance. The victim is positioned on the backboard. The piston pad often
becomes displaced during use and poor performance or injuries can result. Price is about
Vest CPR was developed and studied at Johns Hopkins Hospital and University over the
past 15+ years. Blood flow is achieved by pumping the entire chest with a
circumferential pneumatic vest. Clinical studies indicate improved success as compared
with basic CPR. Combined with ventilation and/or abdominal maneuvers the blood flow
to brain is improved. Cost projection is about $50,000 per device. The device is not yet
marketed in the USA.
Under development is our own Portable Automatic Resuscitation Device (PARD) , an
electrically powered chest compressor.
Virtually perfect CPR can be attained with this device. It is quickly applied and the
operator then may set the strap tension & tap the “go” button. One can select
preferentially stroke distance or stroke force as the primary determinant of compressions.
The rate can be set at 60, 80, or 100 per minute. The base, with a force transducer, rests
in the socket of the chestpad described above (“The Grip”). A battery pack in the upper
section can provide 10-15 minutes of 100 pound strokes at a rate of 100 per minute. This
can allow plenty time to hook up to a secondary battery, wall power, or vehicle power for
continued CPR. As new procedures for abdominal maneuvers and ventilation support
become more commonly used, these devices will interface quite well and should make a
significant impact on survivability. Price will be competitive.
TONGUE-IN-CHEEK or HAND-ON-BELLY-BUTTON ? A position and
technique is described in the ACLS manual for relieving tracheal obstruction (Café
Coronary). This variation of the Heimlich Maneuver has the victim lying on his back and
the rescuer straddles the victim’s thighs. Repeated abdominal thrusts are administered to
force air -and the obstruction -from the victim’s airway. Could abdominal strokes be an
alternate form of CPR ?
Our studies in animals suggest that repetitive abdominal strokes could provide adequate
blood flow to brain with less applied force. Perhaps children or small rescuers could be
more effective with “Abdominal CPR” ???
Percent of “Beating Heart” Values
Chest Only Abdomen Only Simultaneous
CAROTID FLOW (%) 27 +/- 4 29 +/- 4 49 +/- 6
MEAN BP (%) 40 +/- 5 42 +/- 2 60 +/- 3
In this study with 6 pigs, we monitored blood pressure and carotid blood flow during
CPR. Two GRIP devices were employed to monitor compressions on the chest and
abdomen, respectively. Data here are reported as percent of control values prior to
fibrillating the heart. With 100 pounds of force on the chest we maintained about 40% of
normal blood pressure and 27% carotid blood flow. With about 60 pounds of force with
the abdominal strokes, the blood pressure and carotid flow were about the same as with
chest compressions. There was an additive improvement in the “minute blood flow”
when both maneuvers were applied either simultaneously, or (not shown here) with
Our data and others indicate that device-assisted CPR could support brain and other vital
organs to prolong the window of opportunity until application of definitive treatment
with “Ultra-CPR” and surgery described previously.
Advances in resuscitation from cardiac arrest have been slow and frustrating. The
development and deployment of automatic electric defibrillators has already made
stepwise improvement in survival, but even so the percentages are dismal.
Technology is now available to provide more aggressive efforts and save more lives. The
history of thrombolytic therapy, electrical defibrillation, and other novel procedures
indicates that persons who experience cardiac arrest (and meet predetermined criteria)
can be rescued with an enhanced quality of life.
We just need to “make it happen” – – El