X-Message-Number: 0025.2
Subject: Can Life Stop and Start Again?
Simple Facts about Resuscitation
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(The following text is from a book about cryonics that is
still in preparation. Copyright 1993 by Charles Platt.)
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It used to be that when someone's heart stopped beating,
there was nothing anyone could do about it. Then, in the
1950s, CPR was developed.
The idea of CPR is simple--as simple as pushing a
stalled car to get it running again. A person who has been
trained in CPR knows how to press sharply and rhythmically
just below the patient's ribs. The pressure pumps the lungs
and it massages the heart. As a result, oxygen enters the
blood, and the blood circulates--not as vigorously as if the
heart was beating normally, but well enough to sustain some
fundamental processes until the body is capable of running
under its own power again.
From this simple beginning, procedures to revive
patients have been developed into an entire branch of
medicine. Today, in hospital emergency rooms, there are
dozens of techniques that may save people who have no vital
signs at all: from calcium-blocker drugs to extracorporeal
bypass.
Each year, more and more people are saved after long
periods of seeming lifelessness. Some may have suffered heart
attacks; some may have lost a lot of blood; and some may have
been chilled to the point where they were endangered by
hypothermia.
The stories of hypothermia are usually the most
dramatic, because low temperatures help to lengthen survival
time. For instance, the European Journal of Cardiothoracic
Surgery summarized eight cases of hypothermia in a snowy,
mountainous area where the average time without a heartbeat
was two-and-a-half hours . . . one person was in cardiac
arrest for almost four hours . . . yet everyone fully
recovered.
How can this happen?
From the outside, the human body seems smooth and solid;
but this, of course, is an illusion. The truth is that we are
not solid at all. The average human being consists of about
100 trillion individual cells, each of them with a life of
its own.
These cells vary. (A biologist would say they are
"differentiated.") Skin cells act as a protective shield;
muscle cells exert force; white blood cells perform search-
and-destroy missions against viruses and bacteria; nerve
cells send tiny electrical impulses; and so it goes on. But
all the cells stick together, in every sense of the term, to
maintain our physical form.
Under a microscope, a living cell looks like an ameba,
pulsing with activity. The way it functions, though, is more
like a chemical factory. It absorbs oxygen and glucose from
the blood and processes these raw materials to do useful
work.
Cells are incredibly complex. Even now, we still don't
know everything about them. But we know without any doubt
that our ability to think and feel and see depends directly
on the ablity of neurons (nerve cells) to transmit impulses.
If the neurons stop functioning, we lose consciousness and
our crucial processes shut down.
A case history will help to illustrate this. In Elkins,
West Virginia, in 1991, a little girl named Brittany
Eichelberger wandered out into the snow around the trailer
home where she lived with her parents, who were sleeping at
the time, unaware that Brittany had managed to open the front
door. For two or three hours, Brittany was exposed to sub-
zero temperatures. By the time she was found and taken to a
hospital, she was stiff and blue and showed no vital signs at
all. Still, she survived (her story was written up in PEOPLE
magazine).
On a microscopic level, here's how it happened. When
Brittany walked out into the snow, her temperature started to
drop, which meant that her trillions of tiny cellular
chemical factories had to scale back their operations.
Chemical reactions don't just need raw materials; they also
need heat in order to run. As the heat ebbed from Brittany's
body, her muscle cells couldn't contract as vigorously as
normal, which meant that her arms and legs started feeling
heavy, and her heart started beating slower. Her nerve cells
were affected, too; which meant she started to feel tired and
drowsy.
Eventually, she became so cold that her nerve cells
couldn't function at all. The ones in the outer layers of her
brain were affected first, causing her to lose consciousness.
Gradually, as more time passed, the cold penetrated deeper
and her brain stopped sending impulses to tell her lungs to
keep breathing.
Finally, all the tiny chemical factories were at a
standstill. By this time, Brittany had no pulse and was lying
in the snow with her eyes closed. She must have looked as if
she was in stasis; but inside her, a lot was still going on,
and most of it was bad news.
When cells are up and running, they constantly draw in
the chemicals they need and push out the ones that are
harmful. But when cells shut down, this careful chemical
balance is ruined. Calcium compounds come flooding in,
triggering toxic reactions. (This is why doctors give calcium
blockers to protect patients who lack vital signs.) Sodium
also seeps in, bringing water with it, which makes the cells
start to swell.
The condition that triggers these changes is known as
ischemia, and it's often fatal. Eventually, ischemic injury
occurs, meaning that cells are literally poisoned from the
inside.
But in Brittany's case, the low temperature protected
her. It inhibited all chemical reactions--not only the life-
sustaining ones, but the toxic ones, too. Ischemic injury
still developed, but much more slowly. And so, for a few
hours, she was in a state of suspended animation.
Later, when Brittany was given CPR, it forced air into
her lungs and pumped blood through her veins, which carried
fresh supplies of oxygen to the cells. This was like
emergency rations being airlifted to refugees: not enough for
proper nutrition, but sufficient to avert starvation.
Then Brittany's temperature was gently raised, and
glucose was dripped into her blood. This helped the tiny
chemical factories to start operating normally again. Her
nerve cells came back online. As a result, her heart began
beating on its own. She resumed breathing, and she could see
and think and feel.
In this way, her life was restored.
One day, we hope, cryonics patients may be similarly
restored after decades or even centuries in storage at low
temperatures. Unfortunately, cell damage occurs when water
freezes in the human body, and this is something we do not
yet know how to prevent. However, with better freezing
protocol, molecular nanotechnology, or both, we believe that
the problem will ultimately be solved, at which point
resuscitation from cryonic suspension may become a reality.
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