X-Message-Number: 32685
From: "sbharris1" <>
References: <>
Subject: Re: CryoNet #32684
Date: Wed, 30 Jun 2010 17:40:50 -0700

In message #32684 Melody Maxim writes:


>>Most reasonably intelligent persons could easily be trained to perform the
"standby" and "transport" procedures, but the same is not true of the
"stabilization" procedures, which require a proper education and extensive
clinical training, under the supervision of qualified, competent
instructors. Femoral cannulations and perfusion are safely performed, all
around the world, on a daily basis, by competent personnel. A small
percentage of these cases include cooling patients to deep hypothermia
(below 18 degrees C) and removing them from all forms of support, for
procedures that require the cessation of blood flow. These people are
"technically" dead, while the procedure is taking place, and then they are
warmed and revived. These procedures have been successfully performed, for
decades, and what SA is attempting to do should mimic those procedures, for
the most part. SA's cannulation procedures should be identical to those that
have been performed, by vascular surgeons in conventional medicine, millions
of times, yet SA continues to botch these procedures, to this day. <<



MY COMMENT: The statement "SA's cannulation procedures should be identical
to those that have been performed, by vascular surgeons in conventional
medicine, millions of times  is quite wrong. Cannulation in medicine for
femoral bypass is done on patients with a good blood pressure, and this is
true even if the patient is intended to be cooled later. That means the
arteries are pulsatile and pinkish white, the veins properly blue and fat
with pressure, and everything looks like an anatomy diagram.



In cryonics, femoral cannulations are considerably more difficult, and are
not "identical.   There is no good pulse even with the thumper (and the
surgery cannot be done with the thumper running in any case), and time
without blood pressure has usually resulted in enough capillary fluid uptake
that there is little pressure in the vascular system. The "blood pressure 
of a person in early cardiac arrest is about 10 mmHg (in both arteries and
veins), but this only last a few tens of minutes, and is frequently gone by
the time the patient has cooled on CPS for long enough to attempt washout.
In such circumstances it's surprisingly hard to tell veins from arteries. I
think most surgeons would be shocked, but I doubt that many vascular
surgeons have ever tried it, for obvious reasons. Again, even
cooled/arrested patients are *already* cannulated, so the surgeon doesn't
have to do it, then.



Cryonic femoral perfusion is a bit more like what embalmers have to do, but
even here there are large differences. Embalmers do not have to worry about
air in the arterial system, nor introducing long cannula into femoral veins,
or even about tearing a vein plexus during vessel isolation, since they work
with open vein drainage anyway (removing clots with a short narrow cannula
and slide, as necessary, if this stops). For all these reasons, my own
experience with embalmers and funeral industry higher-ups with embalming
licenses, is that they don't turn out to be very good at what cryonics
needs, either.



The major proponent of field femoral washout in cryonics has been myself,
and the only person who has done it consistently is also myself. Even so, I
have failed occasionally, and had to use the (much more straightforward)
carotid/jugular system in the neck for either perfusion or drainage or both,
if the femorals cannot be used. I recently used such methods to perfuse to
vitrifiable cryprotectant concentration in the field, so even this can be
done by these methods.



Elsewhere, at the main facilities at both Alcor and CI, the standard has
been perfusion via aortic arch in the chest, with right atrial drainage, as
in standard bypass. This is easier if one is willing to open the chest, but
people have been less likely to want to do open-chest procedures in the
field. It's possible to teach, but it's even more of a mess, and it may well
interfere with cryoprotectant perfusion later.



I think that part of the solution is to teach neck cannulation as a backup
to femoral cannulation for field washout procedures. I do not think that the
answer can be merely to have human vascular surgeons "on call  to do
cryonics, because they simply aren't available at any hour of any night and
day, 365 days a year. Cryonics cannot be scheduled. The fact that some
vascular surgeons do emergency human heart surgery means nothing: cryonics
will never have the opportunity to draw from this entire pool of working
emergency on-call vascular surgeons to be on call for us. Emergency vascular
surgery is done at tertiary centers, if at all. In standard medicine,
patients who do not make it to such centers alive, die and that's the end of
them. They then go to the nearest funeral home, where they wait to be fed
into that system. We do not have this luxury in cryonics.



A recent cryonics case required 5 days for a patient to die in a hospice
near Alcor. It required 24 hour monitoring by cryonics personnel and they
were exhausted at the end. Had this been a field operation, it would have
required 5 days of 8 hour shifts by surgeons specially sent out into the
field for one patient. This is fairly typical. Nobody could afford that,
even if they could find three surgeons willing to travel for a week at a
moment's notice, and then sit at some hotel doing shiftwork someplace else.
SA has had exactly that problem. It remains unsolved; for the money
available, it may continue to remain at least partly unsolvable.



Steve Harris

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