[extropy-chat] What should survive and why?

[BillK]

On 5/2/07, Heartland wrote:
<snip>
>
> Wouldn't you agree that this is an arbitrary definition of death? After all, every
> portion of Lee's body would function properly and without interruptions, including
> the brain. Would it really make sense to say Lee died during the night even though
> Lee's body (all of it) has remained in perfect health throughout the night? Would
> you be successful in convincing any practicing physician to issue a death
> certificate for the "deceased?"
>



This News article is probably relevant:
<http://www.msnbc.msn.com/id/18368186/site/newsweek/>

The new science of resuscitation is changing the way doctors think
about heart attacks—and death itself.

May 7, 2007 issue - Consider someone who has just died of a heart
attack. His organs are intact, he hasn't lost blood. All that's
happened is his heart has stopped beating—the definition of "clinical
death"—and his brain has shut down to conserve oxygen. But what has
actually died?

As recently as 1993, when Dr. Sherwin Nuland wrote the best seller
"How We Die," the conventional answer was that it was his cells that
had died. The patient couldn't be revived because the tissues of his
brain and heart had suffered irreversible damage from lack of oxygen.
This process was understood to begin after just four or five minutes.
If the patient doesn't receive cardiopulmonary resuscitation within
that time, and if his heart can't be restarted soon thereafter, he is
unlikely to recover. That dogma went unquestioned until researchers
actually looked at oxygen-starved heart cells under a microscope. What
they saw amazed them, according to Dr. Lance Becker, an authority on
emergency medicine at the University of Pennsylvania. "After one
hour," he says, "we couldn't see evidence the cells had died. We
thought we'd done something wrong." In fact, cells cut off from their
blood supply died only hours later.

But if the cells are still alive, why can't doctors revive someone who
has been dead for an hour? Because once the cells have been without
oxygen for more than five minutes, they die when their oxygen supply
is resumed. It was that "astounding" discovery, Becker says, that led
him to his post as the director of Penn's Center for Resuscitation
Science, a newly created research institute operating on one of
medicine's newest frontiers: treating the dead.

With this realization came another: that standard emergency-room
procedure has it exactly backward. When someone collapses on the
street of cardiac arrest, if he's lucky he will receive immediate CPR,
maintaining circulation until he can be revived in the hospital. But
the rest will have gone 10 or 15 minutes or more without a heartbeat
by the time they reach the emergency department. And then what
happens? "We give them oxygen," Becker says. "We jolt the heart with
the paddles, we pump in epinephrine to force it to beat, so it's
taking up more oxygen." Blood-starved heart muscle is suddenly flooded
with oxygen, precisely the situation that leads to cell death.
Instead, Becker says, we should aim to reduce oxygen uptake, slow
metabolism and adjust the blood chemistry for gradual and safe
reperfusion.

Researchers are still working out how best to do this.

etc............


BillK