predator/consent.txt

File: consent.txt
Cont: (pre)venting one's spleen : fine art of consent and legal obfuscation 
Date: 18 Nov 2003


If you take your top off and feel your belly below the left lower margin
of your rib cage, you won't feel anything much, but that's because you're
probably normal. I can, and I'm a bit curious about it.  I normally sleep
face down with a forearm across my abdomen, and of late, stuff has been
moving about inside my guts when I do this, to accommodate a change. This
is 'cos my spleen has become large and relatively rigid, taking up more
room than is normally allocated to it, a condition known by a word which
rolls delightfully off the tongue - splenomegaly.  I knew that's what it
was called, 'cos when, years ago, I did honours and (deliberately) became
acquainted with cytomegalovirus III (which is present in about 90% of the
human city dwelling population, and has called me home for about 20 years)
splenomegaly was one of the listed symptoms of active CMV infection. CMV
usually does fuck-all as long as you're not immunosuppressed or a neonate,
in which case it raises all kinds of hell. I sure as shit don't feel
immunosuppressed and am exhibiting none of the signs associated with that
state (like, being sick all the time). So what's going on?

Spleens (a few people have more than one, some are born without them) are
the centrepiece of your lymphoid system, wherein is trained an
astoundingly complex army of highly specific, molecular recognition
capable, cellular attack dogs. Spleens are connected to the lymph nodes
(most people call 'em glands, such as the ones in your neck, armpits and
groin which swell up when you're sick) via specialised lymphatic plumbing
wherein these attack dogs (lymphocytes) roam in search of specific things
to kill. You can live without a spleen but you tend to be an easier target
for massive bacterial infection if you lack one.

I waddled off to retrieve me ol' Merck Manual (any time you're feeling
hypochondriacal, DO NOT READ THIS BOOK) and had a gawk at the shitlist of
conditions associated with splenomegaly. The 'Manual is best read when
you're in perfect health, since it's pretty depressing if you're not. The
list is extensive and distasteful. It includes EBV (gives you glandular
fever, close viral rello of CMV). CMV (hello old friend, hope it's you).
Polycythemia Vera (broken erythropoiesis leading to too many red cells in
the blood, the spleen has to expand to provide sufficient resources to
destroy 'em). HTLV-3 (which is what they used to call HIV before they
realised HIV was an RNA retrovirus). Wilson's disease (inherited disorder
of copper metabolism). Lymphoma (malignant cancer of the lymph system,
ooh, yummie). Spleens also enlarge for other reasons... sarcoidosis
(nobody really knows what causes this), chronic parasitisation,
spherocytosis, sickle cell anemia, kinks in their associated vasculature.
Various bone marrow fibroses which, on account of their preventing
erythrocyte synthesis, can also provoke the spleen to start making these
cells instead, but spleens aren't very good at it and tend to release
erythrocytes before they're really ready to do their job. With the
exception of CMV, all of these things are probably far too exciting to
apply to me.

So... what's doing it?

I arranged to go and have a full blood count, electrolyte analysis, and
hepatic function test. The analytical processing used in haematology is
heir to knowledge won by humans struggling to understand chemistry and
biochemistry over a period of centuries, but nowadays is mostly automated,
so it's pretty simple, you just pop along, give 'em a few mL of venous
claret (it's always encourgaging that they send it off to the lab in a bag
prominently labelled `Biohazard') and wait for the results to come back.
Inbetweentimes, machines separate your blood into several different
components, humans peer intently at the nature of the isolates, and ponder
upon wether or not your metabolism is broken in some significant way.
 
I got the sheet back a couple of days later and according to it I am,
haematologically speaking, very reassuringly boring, within expected range
for pretty much everything. For a guy who does little exercise, I am
stuffed full of haemoglobin. The things I wanted to know are all there -
specifically, lymphocyte and erythrocyte counts and morphology are
goodish. I'm not gonna turn into a life support system for a load of
tumors just yet (that'll happen later when the mesothelioma starts).

This test ruled out a lot of things, but still doesn't tell me anything
about why this is idiopathic splenic bloat is happening.  The final bit of
interrogation will be an abdominal CT scan, in a day or two. These use
X-rays, so in order to make oneself more radiopaque, one is required to
selectively stuff oneself with heavy atoms in advance of the scan. One
gobbles down a load of barium sulfate the night before (I know all about
that stuff from my Merck Index - same publisher as the Merck Manual,
different topic) to make one's intestines less transparent to the incoming
electromagnetic rays. On the morning of the scan, though, they inject you
with ... well ... something.

The consent form doesn't say exactly what it is with which one is going to
be injected. It mentions that the stuff which will be injected into you is
a radiopaquing agent, implying it's a vasculature contrast medium, and
alludes that the material contains iodine (makes sense, iodine's a heavy
atom, the sort x-rays cannot penetrate) and is non-ionic (exists in an
uncharged state... so what?). Nowhere, however, is the molecule or mix of
molecules actually specified. Iodine in its native aqueous diatomic
state would kill you stone dead if you were injected with it, so
it obviously isn't that. But what is it, exactly? They give an associated
death rate when using this stuff intravenously as less 1 per 180,000. But
which stuff? How can I give them informed consent to shoot me up
with some or other crap if they won't tell me what it is? If they tell me
what it is, I can investigate its metabolic half-life, LD50 and eventual
fate perfectly well in the existing literature, and make a decision.

I'd normally go looking in my Martindales 38th pharmacopoea, but opaquing
agents are not, strictly, pharmaceuticals, so they don't list any, as far
as I can see. 

The mention of iodine, lower down in the form, is an important giveaway...
one can whiz off to the Merck Index and directly observe structures of any
molecules whose names start with io- or iodo-, and grep immediately at the
bottom of these entries looking for the words `opaquing agent'. This won't
get all of them (I mean, there's a heap of different ways to iodinate any
of a squillion different molecules for this purpose) but one can at least
acquire something like a clue about their probable natures.

It appears most of the ones in this section of the Merck are variations
on, or oligomers of, 1,3,5-triiodobenzene. Don't get the idea there's
anything spooky about iodine, one needs it for thyroxine synthesis, and 
one gets goitred without it, among other things. I think I'm going to be
shot up with any of iobenguane, iobenzamic acid, iocarmic acid, iocetamic
acid, iodamide, iodipamide, iodixanol, iodoalphionic acid, iodopyracet,
ioglycamic acid, iohexol, iomeglamic acid, iopamidol, iopanioic acid,
iopentol, iophenydylate, iophenoxic acid, metrizamide, metrizoic acid,
iopromide, iopronic acid, iothalamic acid, iotrolan, ioversol, ioxilan, or
ipodate. I could sieve these entries by their water and lipid solubility
to narrow it down to ones likely to stay in the blood rather than be
incorporated into my cell walls for the next few years.

None of these are radioactive (of course, they just scatter the x-rays,
they don't emit anything themselves)  and I think I excluded all the ionic
ones from the list (and who in hell invents these names?!) But which one?
I got LD50's for mice, rabbits, and just about everything else that moves
there in the Merck, some of these things are actually moderately poisonous
(especially if you're an experimental mouse or rabbit) though you'd have
to shoot a lot more of them up your arm than the equivalent mass of
diacetylated morpine required to kill a heroin user.

I wonder what percentage of the population in general knows what is meant
by non-ionic contrast agent anyway? I know what it means, but don't know
why non-ionisation matters to the procedure.

By signing this form I effectively say to these people, I don't care what
you're gonna shoot me full of, go right ahead. This is, actually, an
_uninformed_ consent document, wherein you put your signature on a chunk
of paper that says that you neither know or care what is going to happen
in this procedure. If, subsequent to some mishap in the scan, you wanted
to get up MayneHealth for compensation, and had made the mistake of
signing this thing, they'd piss their pants laughing you out of court.

And, interestingly, they're right. I actually don't care. So shoot 'em up
and pass the bremsstrahlung, I wanna know what's goin on in my guts.


<predator>



(the next .txt in this series is conway.cat.org.au/~predator/gutful.txt)