How Therapeutic Hypothermia Works

Physicians noticed centuries ago that people exposed to cold temperatures often have amazing recoveries from serious medical emergencies. Now medicine is learning how to purposefully induce hypothermia in order to buy time to fix otherwise fatal trauma.

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Episode Transcript

Speaker 1 (00:00):
Welcome to Stuff you Should Know front House Stuff Works
dot Com. Hey, and welcome to the podcast. I'm Josh Clark.
There's Charles W. Eager Beaver, Chuckers, Brian ready to get
its therapeutic hypothermia on. Yeah, baby, I'm chilling moving at

(00:24):
a glacial pace today, right I am. Um, I'm sorry
for that. That was actually a poke at the author
of this article. Yeah, that's uh. That stood out to
me as well. I'm not telling you. Jerry's over there
and she's stuff you should know. No. Um, Yeah, we
were gooking off about this article and how stuff works

(00:44):
that there were a way too many cold puns for
my liking. There's a lot of puns, you know, a
lot lots of them. Yeah, this article stinks of pun reeks.
So how you doing, man, How you feeling? I'm good. Uh.
It seems there's a sickness going around the office. Yeah,

(01:05):
which I thought we knew here in two thousand and
fifteen that if you're sick, you don't come into work,
especially when you have a liberal telecommune policy right like
we do. I realized, um, I realized that people need
to come in and shoot video and record and all
that but come in, you do that, and you leave,
and you wear like a plague doctor's mask the whole

(01:25):
time you're here too. Yeah, I mean I have a
bio hazard suit at my desk that has a RiPP
in it. Anyone can wear it, has a rippen it,
very small rental and cleaning the You're going to take
a blood sample of mine wearing that thing. And it
occurred to me as you were about to put it on,
like I don't know where that thing has been, Like,
that's a real bio hazard suit and Chuck's going to

(01:48):
use it to open my skin. Yeah, this sounds very odd. Um,
we don't just do this in the office. We did
our blood Types episode live here in Atlanta, and we
actually took Josh's blood type on stage because you didn't
know it. No, I when we recorded the version in
the studio, I genuinely did not know it. Yeah, so

(02:08):
I took your blood on stage. You trusted me. I
did not wear the contaminated suit. No, you you just
used your dirty hands with no like rubber gloves or anything.
Look at you. You're fine ish and you know your
blood type now, which was a positive us guy, So
we should release that whole live show is a just

(02:30):
a special yeah, little bonus. Yeah, bonus. That was the
word I was looking for. There's something special about it.
It's just a bonus. It was special. Yeah, it's a
good idea. Look for that soon, people. So today, Chuck,
we're talking about therapeutic hypothermia and I am very excited
about this. This is my idea of this article. Yeah, um,

(02:51):
it's pretty neat. I don't remember. I guess I first
heard of it from that Mosaic article that we both
read to the big sleep Awesome article. And uh, if
you haven't figured out by now, we have started to
on the podcast page for each episode, put related links
on there on our site stuff you should know dot com,
so that articles on there. There's a bunch of other

(03:11):
stuff on there too that will cover um. But be
sure to check out that Mosaic article. It's very neat.
Um and that article first introduced me to the concept
of therapeutic hypothermia or medically induced hypothermia as another another
term for it, I don't prefer target targeted temperature management.

(03:32):
That sounds yeah corporate, Yeah, very corporate. You know the
HMO term for it, Like, well, we'll call it this
because it'll lessen the likelihood that we'll get sued or
something exactly. Yes, um, But it's been around for a while,
and the the idea that exposing people to lower temperatures
to allow for better medical interventions, which is the whole

(03:54):
basis of therapeutic hypothermia UM, has been around at least
since the napoleon Onic Wars. Yeah, it's pretty neat. I
was interested to find that out. They noticed way back
when in the eighteen hundreds early eighteen hundreds that troops
in battlefield trauma wounded soldiers would the ones who were
not kept warm and cozy by the fire or in

(04:16):
their tents, right, they're just left out on the battlefield
and the cold. Yeah, they actually fared better. And they
were like, wait a minute, is uh? And of course
they had no idea at the time what was going on. No,
They're like, did you notice that, Yes, I did notice
that they're hardy back to our brand, Yeah, pretty much.
But they did notice that the ones who were warm
did a lot worse than the ones that were left
out in the cold, which is super interesting. Yeah, But

(04:38):
the the real investigation into what was going on there
didn't start until the thirties. With a guy named Dr
Temple Faye, and he was actually the first guy to
write about using therapeutic hypothermia. I think in nineteen was
the first paper about it, but he was using it
for a full decade or so before then, basically putting

(04:58):
his patients in ice ba ads, opening the windows to
their room during the winter and um, just basically using
any means he could to lower the temperature for I
think I think he had he was using it on
traumatic brain injury patients. Yeah, and I'm sure he did
a lot of explaining along the way to family members
that were like, hey, can you close the window and

(05:19):
warm up my husband here? And that He was like,
all right, you want him to die? I think back
then too, he was like, it's the thirties and this
guy is a traumatic brain injury. Really, there's nothing I
can do to make it worse, the prospects worse, So
why don't you just lighten up their family member? So
there was another pioneer in the fifties named Dr Peter

(05:40):
safar Um s A f a R. And he actually
began experimenting around with this in the e er as well,
trying to reduce tissue injury. Uh, and brain damage from
a lack of blood flow. Uh. And this was mainly
at the time in like stroke patients, cardiac arrest patients
and what we'll talk more about it. There's all sorts
of well not all sorts. There are several uses, like

(06:04):
cases where you would want to use this and um,
ranging from cardiac arrest to like a gunshot wound. To think,
what is the infant situation. It is called chuck. It's
a type of encephalofy where UM, basically the blood flow,

(06:26):
the lack of blood flow to the brains cut off
for whatever reason, like maybe the umbilical cord gets rappy
on the baby's neck or what have you. Um, it
leads to a swelling in the brain. And they started
using it to medical hypothermia to treat that. That's right,
And that was in the fifties, right, Yeah, the fifties

(06:47):
and sixties is when Dr Safar was doing his work.
So this this is all kind of going on on
the side. And um experiments into hypothermia had kind of
a bad name thanks to the Nazis and a little
bit also the Japanese and World War two. But the Nazis,
especially at Dachau, the concentration camp or the death camp.

(07:10):
There um experimented using unwilling human subjects. Uh, they experimented
on the effects of hypothermia people's bodies. They did all
manner of horrible, grizzly, gruesome stuff, but they recorded the data.
And there was a long debate over the years over
whether that data could be ethically used. And on one hand,

(07:32):
people were saying, no, it's the Nazis. They used unwilling subjects,
as it amounted to torture in the name of science,
and I just used air air quotes, right, And then
other people said, well, wait a minute, these people died,
um whether and we're whether they wanted to or not.
They were made to be these test subjects and they

(07:53):
gave their lives. We can honor them at least by
using the data that was cold from it. Well, once
they really dug into the data that the Nazis had accumulated,
it was just like rank amateurs performing scientific experiments. They
followed like almost no protocol. They did terrible record keeping
of descriptions of subjects and things like that. So um,

(08:15):
it's almost like you just have to toss it out
because you just can't trust it scientifically. The data. But yeah,
but the idea that people were exposed forcibly to hypothermic
conditions kind of gave hypothermia a bad name. So these
guys experimenting with this stuff, it was fringe science for
a while, and then it started to come into the

(08:36):
mainstream and then everybody said, well, wait a minute, hypothermia
has all these bad side effects. Let's just table it
for now. Yeah, and the in the fifties two, NASA
was doing a lot of work during the space Race
because the idea was and this is really sort of
two parts. There's the the modern day uh cooling like

(08:56):
that's not freezing somebody basically, and then you also have
what's called suspended animation, which we'll get too later. Those
are totally different things, totally different things, but they follow
the same process initially, right Yeah, um, well sort of.
I mean, the methods are different, but the same idea
basically is to slow the body down, sown the heart rate,
slow down everything. Yeah. Um, but NASA was doing this

(09:18):
because they put a lot of money into it because
they thought two things. One you could protect astronauts from
a cosmic rays and the other is basically straight up
alien like, we can freeze people on long journeys into space,
and then unfreezing when they get there, which is not
just alien that's a bunch of sci fi movies. But

(09:40):
there was a doctor named James Lovelock back in the
day who was um freezing hamsters until they froze and
then basically until he couldn't hear heartbeat. Frozen. Yeah, they
were clinically dead. Yeah, and then they would he would
put a little uh, a little hot teaspoon against their
belly and warm them back up, and he found that
they were actually okay, and he was able to revive

(10:02):
them some of them. Well yeah, I'm sure there were
losses along them, but I mean even one coming back
to life and seeming normal again is pretty significant. It's
a significant finding, Yeah, because basically the idea was planted
all of a sudden that hypothermia can kill you or
it can preserve you and keep you from dying in

(10:24):
an extreme situation, right, which is kind of counterintuitive, Like
you think of people who undergo hypothermia or you know,
being exposed to extremely cold temperatures, they're dead. I mean,
we've all seen the shining, we know the end. Yeah,
But apparently there's a rule of thumb among e er
physicians and staff that there's no such thing as a

(10:46):
cold dead body. I thought it was measured twice cut once.
It's a little different. That's for the surgeons. Um, No,
there's no such thing as a as a cold dead body.
You're only dead when you're warm and dead, right, Because well,
there's been some some cases throughout the years, the one,
that spectacular one. Yeah, this lady um was she with

(11:08):
Norwegian on a boggenhorn. Um, I don't even know what
that is. It's not an oom out, it's a single
circle above that a. It's very Norwegian. Yeah, um death
metal band name totally. Uh So she was skiing and um,
actually I think she was Swedish, but she was on
holiday skiing in Norway. Um fell headfirst into a frozen

(11:31):
stream and was trapped under ice, submerged for eighty minutes,
stopped breathing, hearts stopped. H Yeah, I mean she was
well known. She didn't drown. They thought she drowned until
they reheated her. Ten days they reheated her and she
was fine. Like weeks and months later she fully recovered.

(11:53):
And basically, if you're underwater warm water, you have a
few minutes at most. But what they discovered it was
if you actually go into hypothermia, it can preserve your body. Um,
which was amazing and a big breakthrough into like, hey,
maybe we can use this right. Yeah, she was one
of a few a handful of people, and we'll talk

(12:14):
about some others too, But um, that what researchers into
hypothermia I've learned and why they figured out that they're
you're not cold and dead, you're just warm and dead,
is that it's not the the the addition of cold
for the exposure to cold that kills you. It's warming

(12:35):
back up in the wrong way too rapidly under the
wrong circumstances, stances that that's what can kill you. Yeah,
it seems like it's a very fine line between well,
we'll talk about the process, but you have to do
it just right on the cooling side and the warming
side if you want to be successful right exactly. You know,

(12:55):
it's uh, they haven't quite figured it all out yet.
This is in the very uh nascent stages. It is
ridiculously primitive and and to the point where it's kind
of like, if you're a doctor experimenting with this, you
you would be like, there's a hud chance that your
dad is going to die under normal circumstances. We have

(13:16):
this one radical technique we can try that might help.
Can we try this? And that that that whether the
dad lives or dies after being given medical hypothermia, he's
still going to end up as like the subject of
a major paper that would be written, because that's where
it's at right now. Yeah, And I read one doctor

(13:36):
said that they they think they pretty much know it's
super possible and will work, he said, but it's the
doing of it that's just really really hard exactly. Yeah,
I mean, like it makes a complete sense intuitively, we
understand like what it's doing. It's just yeah, the fine tuning,
the nuance behind it that is still kind of a mysterious.
The most brilliant doctors say, this's just really hard. He said,

(13:59):
it's really dog gone hard to do. It kind of
makes you go, you know that he know. His quote was,
it's really dog gone hard. And then my quote was,
so we'll talk about medical hypothermia and what it is specifically,
uh in just a minute, all right, So therapeutic hypothermia.

(14:39):
Hypothermia is basically when you lower the body temperature for
various reasons to keep it alive. And right now, what
they're mainly doing now, this isn't the second wave which
is freezing somebody. This is just cooling a body before
and after surgery to help them increase their chances of survival.

(15:02):
Basically your your body. Um, they're doing that now on
this side. They're just not doing the other quite yet.
On humans. Um, So, under normal circumstances, your body maintains
a normal core body temperature. Normative temperature I think is
what it's called, right and um, that's somewhere between like

(15:23):
nineties six and ninety eight point six degrees is a
normal human core body temperature. And all of this is
And dude, do you remember and like when I went
on that crazy weird metaphysical tangent and does the body
replace itself? Somebody wrote in and said, check this article out,
like here's a really great explanation of why things live,

(15:45):
where life comes from. And it was this, Um, this idea,
it's a physics based idea of life and evolution. And
it says that because of entropy, because of one of
the laws of thermodynamics, that atoms will arringe inge themselves
in a way that they can take in energy and
dissipate heat in a really efficient manner, and so of

(16:07):
course they're gonna atoms are eventually going to arrange themselves
into life. It just makes total sense, right. So, being
living things like we are, we take in energy and
we dissipate heat, and that's what forms our core body temperature.
With therapeutic hypothermia, what you're doing is lowering the metabolic

(16:29):
rate through the addition of cold, and so we put
out less heat. And by doing that, we're also lowering
our energy demand, so that that that little engine that's
going all the time and ourselves and our body in
general gets slowed down. And it's not altered in any
way except for the speed and the energy consumption. It's

(16:51):
just slowed down. It's doing everything slower. And you can
do that simply by lowering the temperature of the person. Yeah,
and it's it's not just lower it's um it doesn't
need to be faster. Does that make sense, Like the
heart beat slower because it doesn't need to beat any faster.
It's not like your body is struggling. Your body is

(17:12):
still doing fine. It's just reducing the demand for stuff
like blood flow and neurotransmitter action and stuff like that exactly.
And ultimately, what your heart does is pumps blood, and
what your blood has is, among other things, oxygen, and
your cells need oxygen to carry out these metabolic processes
to burn energy, right, So if they need less, then

(17:34):
your heart doesn't have to beat as much. It's like
you said, it's just the normal processes, but on a
much slower scale. Pretty awesome stuff it is. And it's
just through the application of colder temperatures. Oh yeah, and
in this case, um, and we'll get to how to
do it, But in this case you're not I mean
you're literally cooling the body with like ice packs and

(17:54):
cold blankets and stuff like that pre surgery and post surgery.
It's not the suspended anime some one that we'll get
to when they're actually like pumping frozen saline through your pains. No,
there are, but there are some UM techniques for uh
medically induced hypothermia that do put in like chilled saline

(18:14):
really to chill your body down very quickly. But it's
not like replacing your blood. Yeah yeah, yeah, I hear you.
So there's a couple of applications at this point and
the cases are either involved intervention or prevention. An intervention
is when they're trying to prevent further damage from an
incident like a stroke or cardiac arrest or sort of

(18:36):
the two main ones. UM and then preventative wise, it's
to extend operating time because back in the day you
could not operate on UM. Well, back in the day,
you couldn't stop the heart to operate on it. No,
which is I do you remember we did like this
day in history about the first guy to ever do
open heart centuries of black surgeon in Chicago the early

(19:00):
twentieth century, I think, and he did an emergency open
heart surgery with a beating heart. That guy was totally awesome. UM.
This was the case for a very long time, and
you couldn't stop the heart. And they finally invented a
machine UM that basically does the work of the heart

(19:21):
and the lungs called the exactly where you're transferring blood
through this machine and UM, it's removing c O two,
it's adding oxygen, and it's pumping it back into the
body while the heart and lungs are stopped. Revolutionized open
heart surgery. There's problems with it. One of the problems
is um when the blood comes back in the body,

(19:44):
since it's been through this machine, it may have picked
up some sort of foreign in bacteria, and the immune
system sometimes mounts an attack on the blood. So this,
this machine poses its own problems. And alternatively, an alternative
method for or stopping the heart, of slowing the heart
is to use medically induced hypothermia. So that's an intervention, no,

(20:07):
a prevention, preventative use of medically induced hypothermia. But intervention
is another way, like you said, and it can have
to do a stroke or heart attacks or cardiac arrests. Right,
aren't those two different things? I think so, yeah, technically,
but it's some sort of cessation of the heart pumping blood.
And the big problem with that it doesn't really matter

(20:29):
whether your hand is getting blood for a while. The
big problem that comes from a heart attack is your
brain not getting blood for a while. So here's what
happens when blood stops slowing into your brain. Right, And
we we covered this somehow in the How Dying Works episode. Yeah,
the dying process. Okay, because it's not a it's not

(20:51):
a black and white thing. Uh, you're not alive and
then you're dead. It comes in many, many stages, and
we talked about the stages of death. Yeah, so there's
when what they've discovered is that yeah, you're not like
I'm alive and now I'm dead. Is what we covered
in the How Dying Works episode, Right, like dying in
your sleep? I mentioned that how like nobody dies in

(21:12):
their sleep. That's just a nice thing. That's a nice
way to say they died in their bed overnight. Overnight, Yeah, exactly. Um, so, yeah,
there's with medically induced hypothermia, they've been able to extend
that that time between when you appear to be dead
and when you're actually dead, and by extending that time,
they can intervene um better. And yeah, even a little

(21:37):
bit of time can go a long way. So one
of the one of the things that medically induced hypothermia
has been shown to really help is what's called return
of spontaneous circulation. After uh, you have a heart attack.
The problem is is your heart and lungs can your
cardiopulmonary system can start working again, but you might not

(21:57):
regain consciousness. And in that case, that's a sign that
your brain may be in trouble, your cognitive function, you
may be suffering brain damage at that moment. Yeah, And
isn't the stat one and ten cardiac arrests outside of
a hospital, has it like goes on to live like
a without brain damage. Yeah, because you have a very

(22:18):
small window, and that window is usually longer than it
takes to get to the hospital. Right. So if they
bring you in and you are showing signs of UM
r OSC without return to consciousness too, um, they may
induce medical medical hypothermia. And the reason why is the
heart pumps blood, and blood contains things including oxygen, right um.

(22:40):
And one of the organs that uses probably the most
oxygen of all is the brain, and the brain uses
its oxygen to um burn energy. Basically, it uses it
to oxidized glucose. And when it does that, the reason
it does is because you're neurons, your little neural cells
that fire the way they fires because their chemical battery,

(23:02):
their chemical battery with the stored potential charge, and they
do that by keeping a lower concentration of electrolytes inside
the cell than outside. So this difference creates the electrical
charge that your neurons used to fire. Right on normal circumstances,
that's all well and good, but when they stop. When
they stop getting oxygen, they can switch to anaerobic mode

(23:25):
for a little while, so they're still burning energy, but
they're like, you need to start breathing again because this
is not very efficient. It's like the like when the
emergency lights go on exactly exactly. So UM as a
byproduct of anaerobic um respiration, you get the stuff called
lactic acid. Lactic acid in and of itself isn't bad,

(23:45):
but it can build up. One of the other things
that happens to when these um when this UH, when
that runs out, is the difference between electrolytes inside. Now
inside the cell stops like it evens out, and now
all of a sudden you have things like calcium, potassium,
sodium coming in and out of the cell as much
as they please, and the cell is like, what is

(24:07):
going on? This isn't good and releases its store of glutamate.
And glutamate is a neurotransmitter that excites neurons, and again
in very small amounts, totally fine, it's needed. But when
a neuron just freaks out and dumps all that into
a synapse, it sets off that neuron and all these
other neurons and makes them go totally crazy, and it

(24:28):
also um lowers their structural integrity. So all of a sudden,
you have neurons going nuts, dumping their contents everywhere, and
then creating also free radicals, which are atoms with unpaired electrons,
and they run up against the cellular structure and the
cell walls and start borrowing electrons from those atoms, and
that weakens the structure even more so even more stuff

(24:51):
gets dumped out into the inter cellular matrix, and you
have a problem. This is a really big problem in
and of itself, right, you're still with me, Okay, that's
what happens when you stop getting blood flow. It's just
as bad, if not worse, when you start getting blood
flow again, because you have all these damage cells, you
have dead cells. And when you have dead cells that

(25:11):
have dumped their contents, one of the roles that your
white blood cells your immune system plays is to come
clean up dead cells, because that's toxic stuff. That's bad stuff,
and you need to get it out of your body.
So when blood flow returns again, all of those white
blood cells come to the site of this problem, your brain,
and they start cleaning up. Well. When they do, and uh,

(25:32):
inflammatory reaction happens, and all of a sudden you have
swelling in your brain and the process gets even worse.
So these these um structurally challenged neurons don't just erupt immediately.
They do immediately, but it can continue for hours and
days afterwards. And all of this happens from a heart attack.
But by applying cold temperatures and bringing hypothermion in somebody,

(25:57):
you can actually stop this process. You can stop the
glue to make from ever being dump they're finding and
so give time basically for your brain to rebuild itself
in the way it needs to by lowering that metabolic
rate that your your neurons need. That's what it does
for for a heart attack, cardiac arrest. They're definitely two

(26:18):
different things. I looked it up and someone's gonna say,
you guys should do a podcast on that because you
don't know what you're talking about. Right, it's coming So
probably after that we should take a little break, huh,
I think. So you want to get some tea, yeah,
and uh, we'll be back with more cool stuff. All right,

(26:53):
So how is this magic done? It's pretty easy, actually, yeah,
it's easy in theory, but there are generally three stages
UM for therapeutic hypothermia, and they are induction, maintenance and rewarming,
and they are all very carefully monitored and have to
be done just right. Uh So when they go to

(27:13):
cool the patient, um, they will first thing you'll do
is sedate them because shivering. Uh, shivering is the body's
way of trying to stay warm. Like your body wants
to be warm, and it's gonna do everything it can
until you die, like Jack Nicholson outside the Maze and
the shining exactly to stay warm. Yeah, And you can't
have a body shivering because number one, it fights off

(27:34):
that hypothermia you're inducing, right. Number Two, that uses a
lot of energy, which is what you're combating right there.
You're trying to slow the metabolic rate, not increase it, right,
and you want a patient that's still as well. Like
one of the problems I've seen is the problem with
doctors like performing in these conditions because like stop squirming.
Well that too, and they have to keep the room

(27:55):
very cold. It's not like they're in like an eighty
degree room and they're trying to keep them like everything's cold.
So the doctors have to perform under those circumstances too,
so they may shiver themselves, but to keep the patient
from shivering, they just solve that problem by injecting them
with the paralytic exactly. So now they're nice and still
they're cooling down. Uh the cheap way to do it,

(28:16):
which is um, and they're not doing it because it's cheap,
but um ice packs basically armpits, growing chest. They're basically
wrapping your legs up and everything they can with ice packs,
and that's just gonna cool you down pretty quickly. Um.
Like you said, they will sometimes use like catheters or
a chilled saline solution. Those are more invasive and more dangerous, obviously,

(28:40):
they also work a lot quicker. Yes, very much. And
I think they want to cool people down pretty quickly too, um,
which is I don't think they want to do the
cooling parts slow. No, And that's a really good point.
I'm glad you brought that up, especially if you're bringing
a patient's body down, um to a really low temperature. Yeah,
you have to protect against ice crystals forming in the

(29:03):
cells because that can erupt your cells, and that's a
whole set of other problems, right. Yeah, So if you
bring the temperature down very quickly. You can prevent ice
crystals from forming. That's right, because they require time to form. Yeah,
if it's so, if it's super fast, they won't they
won't form. That's the impression I have. Okay, So during
the maintenance phase, it's you know exactly how it sounds.

(29:25):
Are just maintaining that temperature, keeping a very close eye
again using these cold water packs or forced cold, forced
air blankets and things like that. Um, it's kind of cool. Huh.
They sound kind of cool, the forced cold air blanket. Yeah,
that'd be nice for these Atlanta summers. Get ahold of
one of those. Uh. And there are a lot of

(29:46):
risks along the way. Arrhythmia is a very big risk. Uh,
electrolytes leaving like potassium, which is necessary for the heart
muscle to function as it should. Um, So they're they're
pumping the electrolytes back into you because you're losing them.
So again, they're just maintaining everything. And then the rewarming

(30:07):
part has to be done very very slow. Uh, otherwise
you know, very bad things can happen. And we're talking
um point to seven two point nine degrees per hour
fahrenheit fahrenheit point one five to point five degrees celsius
per hour. Yeah, very slow rewarming process, that's right. But

(30:29):
if you've got a good force their blanket, you can
really control the warming. You get a good brand, not
some off brand. And again they're not like, oh well
if we um, if we heat the person back up
at point one five degree celsius per hour, then this
is what's going to happen on a cellular level. Like

(30:51):
they're not quite there yet. They just know that that's
the sweet spot for rewarming somebody. That's right, So chuck.
One of the really um problematic side effects with rewarming
a person is um. Yeah, they're like, why you start
to get gaming while you were under um is uh
blood clots. So when you're when your blood stops pumping

(31:15):
because your metabolic rate is so low, the blood inside
you starts to form clots thanks to your red blood
cells and your platelets and um, when you warm back up,
all of a sudden, you have clots all over your body.
And that's a real problem that that alone can kill you.
And that's part of the problem with the rewarming process.
But it turns out that investigation into animals that hibernate,

(31:39):
they found that animals have some sort of technique to
where their red blood cells just kind of disappear, and
then once the animal comes out of hibernation, it reappears.
They don't even know where they go, no, but they
do know that they don't get rid of them somehow
and then regenerate some other ones because their reappearance is
so fast that they just think the body somehow absorbs

(32:02):
them and then releases them again. Yeah. And the other
really cool thing and we're kind of into hibernation right now,
which we'll talk about in more detail, but um, white
blood cells. Uh, Hibernators remove white blood cells from their
blood and storm in the lymph nodes and then about
an hour and a half after these animals awake, they reappear.

(32:22):
And this has a couple of functions. One is, when
you're an animal undergoing hibernation, Uh, your immune system is
going to be compromised because as white cells are in storage. Right,
that's a problem. Yeah, it's a problem. But just knowing
that animals can do these neat little tricks with their
platelets and white blood cells, uh, could have like big

(32:43):
effects on us. If we can figure that out for ourselves. Well, yes,
specifically also chuck, because remember when we were talking about UM,
your your neurons dying. Yeah, and when you reperfuse, when
you bring blood back to the brain again, one of
the things that brings with it is those white blood
cell and they start going on the attack. So if
you can figure out how to take white blood cells

(33:04):
out of the equation, it's going to reduce things like
post warming swelling, which can give you brain damage itself. Yeah.
And you talked about the heart lung machine. One of
the big dangers with that machine is a septic sepsis.
And if you have those uh white blood cells stripped away,
then you're not going to be at risk for that

(33:24):
and um, they'll be able to U hang on to
blood longer. Right now. Blood donations can only be kept
a weak um it goes ranked quick, yeah, and transplant
organs can be UM basically cryo protected for longer too,
which is pretty neat So uh, I guess we should

(33:45):
talk about hibernation for a minute, because it's one of
the neatst things in nature. I think uh. In torp
or basically torpor, short periods of hibernation reduced body temperature
and inactivity, and when you link a bun of tor
ports together. That's full on hibernation. So yeah, it's also

(34:06):
like a like hibernation light too. Yeah you know what
I mean, Like you can you can be I think
a bear inners torpor where it's it wakes up like
every once in a while and eats or poops or
does something. And then there's some animals where you can
just shake them like this and they will not wake
up and they're in full on hibernation. Yeah, and the

(34:28):
animals have to prepare for this. They just don't go
betty by and stay asleep for a long time. First,
they become diabetics basically by gorging on food and becoming obese.
It sounds familiar, uh and um, but it doesn't affect
like humans does. It doesn't make them unhealthy like their
body knows it's preparation for hibernation, knows what to do

(34:48):
with it exactly. Plus they're probably also eating unprocessed foods too,
which I think makes a difference. Yeah, you know, I
think so. Um, they don't atrophy like humans do, Like
when we lay around in bed, we don't our muscles
will atrophy. Um. Animals can go months and months without
moving spectacular. Spectacular. It also kind of suggests that humans

(35:10):
aren't supposed to hybernate. Yeah. Well, although you know, when
they found some of these frozen people, they start to
think maybe human hibernation isn't such a bad thing. Um.
Their lungs when you hibernate, become covered at the really
thick like mucacy, uh deposits um. It basically looks like
a human with asthma. But it's you know, a protective measure. Again. Uh,

(35:33):
they go in their brains kind of um, go into
a stage that looks like early Alzheimer's. Again, not a
bad thing, it's just preparation. Uh. And it it's weird.
I mean, it looks like animals are almost dying when
they're preparing for hibernation in some cases, and sometimes they do,
especially when they're forced to come out of hibernation and

(35:54):
then go back in. Their energy stores aren't aren't built
for that kind of thing. Like, so they probably will
die because they'll start to death because it required so
much energy to wake back up again. Or they're also
vulnerable to predators too. Yeah, good point, which makes you wonder,
like what's the point of hibernation and the point is, Well,
it's they don't have enough energy to go elsewhere when

(36:17):
temperatures get cold, so they just kind of shut down
their metabolic demand when food becomes scarce and um For
the longest time, we didn't think that any um uh
primates could hibernate until two thousand four when they found
a lemur from Madagascar that could hibernate and uh, well

(36:40):
at least go into the regular torpor hibernation light still
and they said, we share about of our genes with
the lemur, and they said, it's basically our cousin. Yeah,
I mean that. The doctor basically said it would be
really remarkable if the ability to hibernate light within that
that we don't have. So basically humans may have more

(37:01):
of an ability to do this than we think. It
would just have to be medically induced. Well, you know
who demonstrates that very well, Chuck. Is that a man
named mitsu take Yu chi Koshi. Oh, yeah, we talked
about him. What do we talk about him? And was
it cryogenics episode? It was a long time ago. I
don't remember that one. Cryogenics that's a good one, that's

(37:21):
a good title. But yeah, I remember this guy though.
For sure. So he is a Japanese man who, at
age thirty five, was hiking with some friends in Japan
and he decided to turn back by himself to go,
I don't know, get something out of his car, and
he wandered off and apparently in a meadow, Um tripped

(37:42):
over a rock and fell and hit his head on
another rock and laid there in exposed to these cold
temperatures on this mountain for twenty four days. And he
was found basically in a state of hibernation. His body
temperature was through the lore. Yeah, and um, he had

(38:02):
almost no pulse. His temperature was seventy one degrees which
is twenty two degrees celsius. That's his body temperature. That's
pretty that's like a hypothermic state. And he was in
this weird kind of state of suspended animation for twenty
four days. He went without food, water, nothing, just laying
there um living in some weird way until he was

(38:26):
rescued and returned to um complete normalcy. Yeah, it's like
the lady the skier who was frozen, Uh, not nearly
for his long But these cases where humans bodies are
defying what we thought they could do, you can give
US insight into like, hey, how do we manipulate this
for good? How do we use this to get to
the stars? All Right, So I mentioned earlier that NASA

(38:47):
was kind of leading the charge for um this really
cool suspended animation where you're basically freezing a person like
Han Solo um in carbonite. Yeah, if it's not carbonite,
it's not exactly like that, but it's it's sort of
like that. Actually it's not like that at all, right,

(39:08):
um And where NASA dropped off of, the U. S.
Army picked back up with some funding because they basically
said on the trauma hospitals during wartime are chaos because
you're trying to to save a person. You're trying to
treat their immediate wound, You're trying to stabilize them, you're

(39:28):
trying to make them better, you're trying to prevent blood loss.
It's it's not an easy thing to do. It's not
like mash you know, where they just make it look
super simple. Right, Well, everybody's dunk on homemade gin. Yeah,
so they're thinking, Um, I wonder what that stuff tasted,
like I always wondered. But they're still they seem to
like it pretty much pretty well because they didn't have
anything I know, but they really seem to enjoy it well.

(39:49):
The way they handled it was very much like a
fine martini. But you know, it's just like swill. I
don't know they were at it for several years. Yeah,
that's true. We'll have to ask Alan all of the
um man to meet that guy, one of my heroes
for attention, Alan all the reach out to us, so
Chuck can meet you. That would be great. My brother
met him, I'm sure he did. He probably gets Christmas

(40:12):
cards phones, No, but he did get a picture with him,
which is pretty neat. Um So where was I? Oh yeah,
mash operating rooms. Yeah, because if you're a doctor, even
in a battlefield hospital, you're like, I want a coffee
break too, and so to be like, I don't have
time for this guy right now, freeze him to have
that ability that would be magnificent. Or if you did

(40:35):
have time for the guy, but you literally didn't have
time to fix these horrific wounds that he came in with,
you could also say freeze him to buy me some time,
and that will let will give you the time to
basically operate on this guy and completely repair heart or
his brain or what have you. UM, And that's what

(40:58):
medically induced hypothermia does. It just it buys you time
for either the body to heal itself in ways we
don't understand, or for you the surgeon to sew somebody
up who without hypothermia would just be a lost cause. Yeah,
there's a doctor named Sam Tisherman from the University of
Maryland chirps working with the University of Pittsburgh. Um, what

(41:22):
are they panthers, University of Pittsburgh, pitt Panthers. I think
so that sounds right. It does, we'll go with panthers. Panthers. Uh.
If I got that right, I'm so sorry, Pittsburgh. We'd
love you. UM. But he is working hard to UM basically, uh,
put patients into severe hypothermia or suspended animation. They're calling

(41:47):
this emergency preservation and resuscitation. And this is the one
that they haven't yet experimented on humans. They think they're
pretty close, but this is the one where they flushed
the body with freezing cold saline solution um which prevents
ice from forming. Yeah, and it's worked on dogs, and
I think works on dogs, gotta work on humans. Well,

(42:10):
they did some experiments on pigs too, because one of
the one of the things they think they can do
where it's not like if you've had a hard cardiac
arrest or a stroke, but again, with trauma like a gunshot,
you just can't. And I didn't I never knew this.
You can't resuscitate a person with CPR that's had blood
loss due to trauma. It's completely different than cardiac arrest.

(42:33):
Why because the close circulatory system has been opened. I
have no idea. I bet that's it. Because of the
dropping blood pressure. It's just not working. It's like sucking
through a straw that has a hole beneath your lips,
like a lot of it's escaping, a lot of the
air's escaping, so you can't get as much draw. Yeah,
I guess that makes I'll bet that's what it is.
All right, Well we'll probably find out. Um, But with

(42:55):
mel and all with trauma like a gunshot wound or something,
or a stab wound where you lost so much blood
you're dying. Um. This is when they're using these super
super cold temperatures. Um. It's a tube inserted into the
a orda literally and they've done this on pigs in
two thousand six, they examined um deep, profound and ultra

(43:17):
profound freezing of pigs who had uncontrolled bleeding wounds. And
I imagine that, yeah, imagine they induced those as well. Student. Yeah,
there's one creep post doc could get to do you
know all the stabbings. Um, yeah, that's why I'm here.
I'll get ronnie. Um. And they found that the ones

(43:40):
who went underwent the most profound hypothermia had the highest
survival rates, like those French soldiers on the battle exactly.
And then in two thousand they did the same thing
with dogs, except that why they weren't stabbed it was
dogs and cardiac arrest. Um. They may have induced that
too though, come to think of it, they'd be like,
you want this phone, now you can't have it. But

(44:03):
they use ice cold ceiling in that case, and their
chances of survival with no brain damage really increased. So um,
it's you know, there are risks though, it's not the
easiest thing to do, like we said, and um, I
know pneumonia was one of the risks for years. Um,
even with just the regular cooling, right. Uh. Yeah, pneumonia

(44:25):
slowed heart rate. Apparently you can enter hyperthermia while you're
being rewarmed, like you get way too hot, your body
temperature increases too dramatically. There's a lot of problems that
blood clotting is still an issue and probably will be
for a while. Yeah. With Tishrmann's case, trying to use humans, though,
there's a couple of problems. Um One is they have

(44:46):
to get consent from a person to undergo an experiment
like this, But you can't give consent when you're wheeled
in there unconscious from a cardiac arrest. So what he's
trying to do is just spread the word literally, to
spread the word to the citizens in his area that
there's this thing, and if your husband or wife has
a cardiac arrest, ask for the cold treatment where we

(45:10):
completely pumped their blood out and replace it with frozen
sailinge using cold sailine. It's pretty amazing, it is. And
you know, there's a lot of people who are still
very skeptical of the idea that medically induced hypothermia can
actually work, but there's also a growing body of studies
that show that it does that has a significant impact.

(45:30):
Like there were a couple there were several in two
thousand two that really broke the thing open where it
was like, these people have a twenty five percent chance
of recovery without it, they have a fifty or seventy
chance of recovery with it. And that's really tough to ignore.
It's amazing, amazing stuff into the future, Chuck, let's go.

(45:52):
If you want to know more about medically induced hypothermia,
check out our podcast page for this Episode's got a
bunch of cool links, and you can type uh therapy
peutic hypothermia in the search part how stuff works dot
comm and it will bring up this article full of
puns and Uh. Since I said search part, it's time
for listener mail. I'm gonna call this um Josh's theory

(46:14):
on satire. Remember that we talked about that in the
very recent show clown Clowning. Uh, do you want to
summarize your position real quick? But maybe satire is just
a release and does it affect change that the nuts
and bolts of it. Yeah, Basically it lets the populist
who's angry let off steam at the leadership without actually

(46:35):
forcing the leadership to change. All right, So that brings
us up to speed. And this is from Chelsea. She said,
I just started listening under a year ago when a
change in jobs landed me with a twenty five minute
walk to and from work every day. I think she's
in Dublin, um, she says, I find myself laughing out
loud at your repartee, and my boyfriend is affectionately started
referring to you as my nerd friends. But he's a

(46:57):
listener now to it sounds like Dublin. I'm actually writing in.
Regarded Josh's theory on satire, it's a really interesting point,
an angle I had not considered myself. I think, though,
that there's another way to look at it, which is
that satire has the ability to plant the seed of
descent in a non threatening way, and thus can eventually
be a force of change. For example, someone may not

(47:18):
be aware of a particular foible of a leader. The
satirist points it out in a funny way. Now that
someone has an awareness without feeling preached at, and has
it in their mind the next time the leader does
something untoward, or perhaps they were just uh, they were
aware of said foible, but the satirist opened their eyes
to just how ridiculous and or dangerous it is. So

(47:38):
while there's certainly a possibility satire connect as placation or
a way of letting off steam. There's also a very
real possibility that can spark be the spark that ignites
an eventual change. It's a good point. Yeah, and that's
from Chelsea and Morgan Hoffman. Thanks a lot, Chelsea Morgan
Hoffman of Dublin, Ireland. Probably well, she just said Dublin, Dublin, Georgia.
I'm gonna go ahead and assume Ireland. Yeah, and boyfriend, Yes,

(48:01):
thank you both for listening. We appreciate it. Uh. And
if you have a counterpoint, or your own theory or hypothesis,
or just want to say hi or whatever, you can
tweet to us at s y s K podcast. You
can join us on Facebook dot com, slash stuff you
Should Know, UH, you can send us an email to
stuff Podcast at how stuff Works dot com, and as always,

(48:21):
joined us at our luxurious PHLM on the web, Stuff
you Should Know dot com For more on this and
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