X-Message-Number: 16255
Date: Fri, 11 May 2001 01:14:47 EDT
Subject: Kryos News #4



By Mike Darwin


Cardiopulmonary resuscitation (CPR) doesn't work. 

That's an extreme statement but not far off the mark. If that's the case then 
a lot of "whys" and "what's" are in order:

Why not?
Why is it still used?
Why was it ever widely practiced?
Why use it on cryopatients?
What good does it do?
What can be done to improve it?
What will improving CPR involve?

These are all good questions and my purpose here is to answer all of them. 
Perhaps the first order of business is to explain the mechanics of CPR and 
how it came to supplant the resuscitation techniques which preceded it. In 
the early 1960s the standard method dealing with both cardiac and respiratory 
arrest was to open the chest and directly squeeze the heart forcing it to 
pump blood. The lungs were inflated with positive pressure ventilation using 
a respirator with either a mask or a tube in the windpipe. In the very early 
1960s the technique of mouth-to-mouth artificial respiration was developed. 
The easy applicability of mouth-to-mouth ventilation in the field, especially 
to drowning victims where it replaced the cumbersome Schaffer prone position 
push-pull ventilation technique, lead to increasing demand for a way to 
restore not just breathing, but also circulation.

Enter Kouwenhoven, Jude and Knickerbocker in 1960. They presented a pilot 
study of a new technique called closed chest CPR in a series of 20 patients 
with an overall success rate of 70% {Kouwenhoven, 1960}. The technique caught 
on rapidly and resulted in many highly publicized almost miraculous 
resuscitations. Within less than 5 years closed chest CPR had replaced open 
chest CPR as the standard method of cardiopulmonary resuscitation in the 
hospital, as well as in the field. The peculiar thing about this is that in 
all the enthusiasm for the new closed chest technique, no one bothered to do 
large, multicenter, randomized clinical trials to validate how well it 
worked. By the 1980s a growing number of clinicians in the critical care 
setting had come to realize that overall survival after CPR had declined 
precipitously {Alifimoff, 1987}. In fact, it had dropped from nearly 20% in 
witnessed in hospital arrests to less than 10%. More alarming still was the 
grim fact that while greater than 90% of patients resuscitated with open 
chest CPR survived without brain damage, only about 20% of similar patients 
survived with neurological impairment following successful resuscitation 
using closed chest CPR.


Now, 41 years later we see the inadequacy of CPR slowly being validated by 
the following changes in the way resuscitation from cardiac arrest is 
delivered. First, students learning bystander CPR are no longer told to start 
CPR and then call for help, rather they're told to call for help and then 
start CPR. The reason for this is the second major change in how care is 
delivered: the realization that early defibrillation by delivering a powerful 
direct current shock to the heart yields the highest survival rate and the 
lowest incidence of neurological morbidity. 

So powerful is early defibrillation that the American Heart Association and 
the American Red Cross are proposing that lay people be trained to operate 
automatic defibrillators and that these devices should be on airplanes, as 
well in shopping malls, stadiums, gambling casinos and other places where 
large numbers of people of a wide age cross-section gather. If they were 
cheap enough, one presumes these August organizations would want one in the 
home of everyone who is at risk of sudden cardiac death. In fact, they are 
cheap enough: about $900 for a basic model, and if I had a history of serious 
heart disease I'd buy one.

The last two decades have seen serious calls for a return to open chest CPR 
in the hospital setting. Even more telling is that over the past 30 years 
there have been well over two thousand papers published on ways to improve 
the efficacy of closed chest CPR. That's a staggering amount of time, money 
and effort which has been expended. 


So we come to the question why is CPR still used? Is it totally worthless? 
The answer to the second question is a qualified "no." In victims of drowning 
and electrocution, in the very young and in those in whom CPR is started 
immediately and advanced cardiac life support (ACLS) from paramedics quickly 
follows CPR can be a real life saver. The unfortunate fact is that most 
people who experience cardiac arrest do not fall into these categories. Even 
if CPR is started within seconds of cardiac arrest, unless ACLS is available 
in ten minutes or less the patient has essentially no chance for recovery. 
This sobering fact should tell us that CPR is failing to do the very thing it 
was promoted to do: restore adequate circulation and respiration by 
artificial means until spontaneous breathing and heartbeat can be restored.

Why did closed chest CPR become the dominant practice? The answer is complex 
and tragic and it bears many sad parallels to the problems of cryonics. 
First, the initial study was far too small and contained patients with a 
selection bias towards those most likely to benefit from the technique. 
Second, people wanted to believe that closed chest CPR worked. They felt 
helpless and totally disempowered to do anything when a loved one or even a 
stranger suddenly collapsed and died or suffered misadventure which stopped 
their vital functions. Third, the technique was easy. As Kouwenhoven said 
early on "all you need to save a life is your two hands." Fourth, once it was 
going CPR became a big business. There were mannequins to sell, money to be 
raised to train instructors and teach the community, millions of manuals, 
pamphlets and slide presentations to manufacture and distribute. While all of 
this was done with the best of intentions no one ever stopped to do the most 
fundamental cost-benefit analysis. What exactly are we getting for these 
hundreds of millions of dollars we're spending teaching people how to pump on 
chests in just the right way? The answer, of course, is not very much, at 
least within the framework of cost benefit decisions in medicine as it exists 


I probably should pause here to change terms and explain why. For medicolegal 
reasons we do not refer to CPR as CPR in the context of using this technique 
on cryopatients. Rather, we call it CardioPulmonary Support (CPS) because our 
goal is not immediate resuscitation of the patient.  I wish we had a better 
combination of words than CPS because CPS is increasingly being used in 
mainstream medicine to refer to modalities such a ventricular assist devices 
and temporary pump-oxygenator support of seriously ill patients until they 
can recover sufficiently to be self-supporting or until they receive a heart 
or lung transplant. Most cryopatients in a medical setting have what is 
called "no code" or "do not resuscitate" (DNR) status. This specifically 
forbids the application of CPR and it has proven problematic in the past to 
make medical personnel and even hospital lawyers understand that what we are 
doing is maintaining circulation only for the purposes of providing a 
temporary window of support and to facilitate cooling, delivery of 
medications to protect against ischemia, and generally prepare the patient 
for cryopreservation. So, from here on I will refer to CPR as CPS in the 
setting of cryonics procedures.


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