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On Chokes
A letter by by Wendy Gunther, M.D.
Couple of years ago I read in the medical
literature a report from a bunch of scientific
wackos who hooked up judoka to heart monitors
and EEG equipment, then had them choked out by
their sempai. The monitors showed that blood
flow to the brain is indeed momentarily
interrupted (surprise, surprise) and that there
are temporary EEG abnormalities while
unconscious, but that full recovery occurred
after each choke. One fellow was willing to be
choked out five times for Science and each time
he had the same level of function that he had
before (of course, you gotta wonder what's the
baseline for a person who is willing to be
repeatedly choked unconscious for Science?).
The forensic literature says that if you are
going to kill a person by interrupting blood
flow to their brain, you need to hold pressure
for minimum two minutes. How they got this
information I do not know. People have been
convicted of murder based on it, because having
to hold pressure for two solid minutes is good
evidence of intent. Reversing this, it would
suggest that if your friend chokes you out and
lets go as you hit the mat, you ought to recover
fully just as the judoka in the experiment
recovered fully.
However, interrupting blood flow to the brain is
not the only way to cause death. There are two
other methods with which you should be
concerned. One is bradycardia and arrhythmia
based on carotid sinus stimulation, and the
other is positional asphyxia.
The bradycardia one means that if you're choking
just the right spot very high and fairly lateral
on the neck, up behind the sternocleidomastoid
muscle and only an inch lower than the jawbone,
you may accidentally put your thumb on the
sensor located in the wall of the carotid where
it divides into internal and external branches.
That sensor is there to tell the heart to slow
down if the blood pressure going into the brain
is too high. If you push hard enough on the
vessel and up the pressure in it, the sensor
tells the heart, "Whoa! We gotta surge of 80 mm
Hg in here! Back it off!" And the heart
obediently slows down to nothing, at which point
it can start to fibrillate and you die. The
reason this is rare is dual. Number one, the
sensor is small and hard to get to, so it's
chance if you happen to be over it. Number two,
young people with resilient arteries are almost
all resistant to this reaction to carotid
compression. Old people with hardened arteries
are much more susceptible. However, this has
been thought to be the genesis of death in cases
in which the perpetrator confessed, "I was mad
at her, yeah, and I took her throat in my hands,
but honest to God I didn't do anything! She just
went limp the instant I touched her!" and the
autopsy is negative. So this is always something
to bear in the back of your mind when practicing
chokes: if your partner is the one in a thousand
whose arteries aren't resistant to this, and if
you hit exactly the right spot, they could go
limp in your hands and die without your even
achieving a good choke. Scary.
Positional asphyxia is likelier because one
tries to get it in judo. If you're on his
diaphragm so he can't breathe, and you choke
him, and you hold it too long, he might die.
Again, if your choke lasts only a second or
three, this is unlikely. It is much likelier if
he is hog-tied or even merely face down. I would
never practice chokes with a face-down opponent.
Tracheal compression is less worrisome to me,
even though an element of it is present in most
judo chokes (correct me if I mean strangles --
I'm not a judoka), simply because it takes so
much effort to do it enough to flatten the
C-shaped trachea. And you'd have to really
flatten the trachea to prevent any air at all
from going back and forth. I have been told it
can be done easily from behind with a
nightstick, but I have never seen it done from
the front or back with hands alone; if you get
your hands, or his collar, into good tracheal
compression position, you're probably pressing
on his jugulars and carotids too, and he'll go
out from those long before you significantly
flatten his airway. A good thing -- the vessels
recover completely from being pressed flat; the
airway gets damaged, and it can swell up and
choke off air flow minutes to hours later. If
any of you has access to Spitz and Fisher ed.iii
(the $190 volume that's the bible of the
forensic pathologist), on p. 447 Spitz says: "It
is said that five pounds of pressure per square
inch suffice to occlude the carotid arteries and
jugular veins. Thirty-two pounds are required to
block the airway." And later, on p. 448 he goes
on: "Actual compression of the airway by the
noose in hanging cases is not as common as is
generally believed. Supportive evidence for this
includes the finding of vomitus in the airway of
numerous hanging victims. Suicidal hanging by
persons with an artificial opening into their
airway (tracheostomy) below the level of the
noose also illustrates this point. Such
individuals continue to breathe while dying"
(presumably, of jugular/carotid compression).
"Obstruction of the airway usually elicits a
struggle, a dramatic condition known as air
hunger. ... Judging from the circumstances in
which [jugular/carotid compressed] individuals
are found, there is certainly no indication that
this is an *unpleasant* mode of death."
(Emphasis his.) So if you're gonna choke 'em
out, and you wanna be nice, or you don't want to
elicit struggle, seems like you would go for the
five-pound vessels rather than the
thirty-two-pound airway. Unless you're old-style
LAPD.
He also quotes Reay and Eisele's fascinating
1983 article in the American Journal of Forensic
Pathology, "Death from law enforcement neck
holds," to say that in the judo-derived police
carotid sleeper hold, "blood flow to the head is
reduced by an average of 85% in approximately
six seconds... Despite the apparent harmlessness
of the carotid sleeper hold, occasional deaths
do occur... Movement during a struggle may turn
a sleeper hold into a choke hold with serious,
even fatal, consequences", which I think was
Ken's point.
I grant you that there is a midpoint between no
harm and death called brain damage, but, Ken, I
have never seen a successful suicidal hanging
resuscitation that ended up brain damaged, only
fully resuscitated or dead. Of course I do not
know the literature on this point.
Yours, Wendy
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