X-Message-Number: 33372
From:
Date: Mon, 28 Feb 2011 01:49:14 EST
Subject: Melody Maxim's Distorted Reality 7
This is the report from me that Ms. Maxim characterizes as follows:
Mike's report seemed so hostile, I found his review truly offensive, from
the first page, on. (In Mike's defense, many who haven't witnessed some of
the bad behavior that goes on within cryonics organizations and who have
read my posts on this forum, might feel the same thing about me. At this
point in time, I can truly understand Mike's hostility.)
Even if I could look past what I perceived as Mike's hostility, I
disagreed with a lot of Mike's advice and opinions, especially in regard to
perfusion and perfusion equipment. (FD is going to want me to elaborate, but I
truly can't remember many of the details, I just remember disagreeing with a
lot of what I read. The technical details of the specifics I can remember
would take me too long to explain, on this forum.)
Judge for yourselves:
[Note: My agreement with SA was that none of the consulting done was
confidential, and at that time SA had a policy of complete transparency with
regard to technical and scientific issues.]
Input From Mike Darwin 08 June, 2006
My comments below will be in red where embedded in the text below.
Some Painful and Arduous Background
Before I get into the text I want to provide some commentary and
background on the major paradigm shift suggested and shown in the photographs
below.
That is principally the use of a hard-shell venous reservoir as opposed to
a compliant bag. I like hardshell reservoirs and started out pumping them;
the very first was the late 1970s era Bentleys, and of course Kay-Cross
disc oxygenators before that.
When we first started doing in-field CPB and blood washout in cryonics we
used the dominant technology of the time which was bubble oxygenators.
Below is a photo of a typical 1980s in-mortuary cryopatient washout using a
Shiley S-100A bubble oxygenator. The gentleman in the picture is professional
perfusionist and cryonics pioneer Jerry Leaf (now deceased).
The picture of an in-field femoral cutdown (below) is included simply
because it shows me (almost 20 years ago) using the same technology (Im the guy
to the right, opposite Jerry):
I include these images because I want to provide historical context and to
hopefully demonstrate that I am conversant with hard-shell reservoirs and
am comfortable using them.
Both Melody and Boon are correct in the advantages they cite for
hard-shells and what I am about to say will probably seem incredible to both of
them.
The Alcor Foundation is the largest and most medically oriented of the
existing cryonics organizations. Indeed, both of the case photos you see above
are of Alcor patients. In September of 1991 Jerry Leaf entered
cryopreservation and a year later I was dismissed from Alcor. A young woman
with no
prior medical, biology, or basic science background, was given control of the
cryopreservation team and transport operations at Alcor. A veterinary
surgeon with no prior experience in CPB was brought in to do the thoracic
surgery.
Almost all basic elements of safe (or rational) technique were either
severely degraded or disappeared at this time. Rational selection of cannula
size and even the use of venous cannula during femoral-femoral washout
vanished. Mortuary embalming pumps were used when convenient (often because
something was missing from the washout field kit which disabled it). Proper
securing of cannula via the use of properly anchored tubing holders and
securing the red Robinson snares to the tubing with umbilical tape stopped. An
immediate consequence of this was that arterial cannula began to pop-out of
the aortic root in about one in three cases. Since no one knew to clamp the
venous line when this happened, and the patients had little intravascular
pressure (MAP ~ 35 mm Hg), there was massive air entrainment in the aortic
root where it could not be seen with the consequence being massive air
embolization of these patients.
In one case (a dear friend of mine), the arterial line was mistakenly
placed in the femoral vein and a very small bore venous cannula was placed in
the femoral artery and bypass was initiated at near physiologic flow rates.
The result was massive splanchnic edema and epistaxis due to rupture of
vessels in the sinuses: one can only imagine what the effect on the brain
capillary bed was.
Standard practice at Alcor has been to use a very small in-house
fabricated hard-shell reservoir for cryoprotective agent (CPA) perfusion which
is
run with only 100cc to 200cc of volume in it. Air is routinely entrained into
the arterial leg of the circuit and it is dogma that the air separation
membrane on the 40 micron Pall filter will remove this air. This reservoir is
also stirred continuously, using a magnetic stir bar to create vortex
stirring, with accompanying creation of massive quantities of microbubbles. The
CPA perfusate is at least twice as viscous as blood and has multiple
polymers that create very stable foams and delay the gravity-mediated removal
of
microbubbles for many minutes far beyond the design constraints of
arterial filters used for blood in CPB circuits. I have written extensively on
this; http://www.cryocare.org/index.cgi?subdir=bpi&url=tech5.txt
However, despite identifying this problem and creating a solution, no
changes have been made in the subsequent 12 years.
The young woman I mentioned previously returned to Alcor several years ago
and continues to be the dominant technical presence.
The quote below is from a brief case summary of a patient perfused in
Alcors facilities in August of 2005
(http://www.alcor.org/Library/html/alcornews043.html):
"Once at the lab, the open heart surgery for this whole-body
patient was begun, followed by the introduction of the
newest cryoprotection protocol. At around 30-40 percent of
our target concentration, the system filled with foam,
which was subsequently pumped into the patient. Perfusion
was stopped, and the foam was methodically removed from the
cannula and the aorta, to the best of our ability to do so.
This incident highlighted many problems, not the least of
which was that the perfusionist had stepped away from his
station without providing for a replacement. Other problems
contributing to the foam were the ice blockers themselves
(X-1000 makes a rather stable foam); the cardiotomy suction
system was introducing bubbles into the mixing reservoir;
and the mixing reservoir was being run low. It took us a
full hour to de-foam as much as we did.
Cryoprotection was terminated after refractive readings in
both arterial and venous samples remained above the target
for a half hour. The patient experienced severe edema, and
we have several theories about what contributed; changes
will be made to the whole-body protocol as a result.
The patient, Alcors 64th, was pronounced in the early
morning of May 13, the expected medications were
administered, and she was then removed to a funeral home.
Because of extensive sclerosis in the femoral vessels, the
patient was washed out using the right carotid, but this
fact was not communicated to the operating room team and
precipitated an early cryoprotective ramp. Because the neck
was obscured by ice bags and drapes, we failed to locate the
additional source of leakage in an already difficult
surgery. Despite the problems during surgery, the
cryoprotection went fairly well."
Content-Type: text/html; charset="US-ASCII"
[ AUTOMATICALLY SKIPPING HTML ENCODING! ]
Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=33372
Warning: This message was filtered from the daily CryoNet digest
because the poster sent too many messages per digest.
It thus may need to be rated.