This is an important table and before begin,
though, let me set up the topic. First and foremost,
understand what is this saying. Do not breeze
past the topic. The effective circulating
volume, stop there. You see that. Effective
circulating volume, what does that mean to
you? Is that the ICF? No. Is that part of the
ECF? Yes. It is part of the ECF. So what part
is this? What is the effective circulating
component of your ECF? Plasma, good. So here
all we are dealing with is the plasma compartment
when we say effective circulating volume.
Is that a typo? This does not equal an excess
fluid volume? No, it's not, not a typo. It is absolutely
accurate. You can have a decrease in effective
circulating volume and not at all be equal to
the decrease in extracellular fluid ECF and
we'll go through examples where that becomes
very true. So what does ECF mean to you? ECF
is a combination of plasma and interstitium.
For example, is it possible that you might
have an increase in ECF and a decrease in effective
circulating volume? That were a rhetorical question.
Of course. Example, oncotic
pressure is decreased secondary to cirrhosis,
congestive heart failure resulting in increased
hydrostatic pressure. What did I just say? Liver
has been damaged, you don't have enough protein,
decrease oncotic pressure. Example number 1, clinically.
Example number 2, congestive heart failure, hydrostatic
pressure and so therefore where is that fluid
moving? From the effective circulating volume,
which is not decreased, into the interstitium.
So what happen to ECF? It has increased, now
you see it clinically. Because if we
just rush pass through this, all you done is either
not paid attention or you just memorized it
and it does not stick. Now on this table,
we will go through each one of these examples
so that you can clearly see this. The overall
theme for this table as you see is decreased
effective circulating volume. Let us take
a look at the first column here, decreased
extracellular fluid volume. Take a look at
the concept for the slide, which is the difference
between what we call ECV, effective circulating
volume, and ECF, extracellular fluid volume,
okay. I am going to keep repeating this so
you are not confused. The entire theme for
this table is decreased effective circulating
volume. What is this? The plasma only. So
here let us say that you do have volume depletion
due to hemorrhage. Got into an accident
and there has been a laceration in which there
is massive loss of blood. What happens to
extracellular fluid? Decreased. See the first
column. That is ECF, but what about ECV? Obviously
decreased as well because you have lost all
blood hemorrhagically externally. There it
is on the floor. You see a lot of blood. Oh!
My goodness, I miss you so much. So now that
is hemorrhage that dramatic enough for you.
So you have a decrease in ECF and you have a
decrease in ECV.
Next point, a normal ECF and decreased ECV,
what is going on here? It is a sepsis.
In sepsis, what are you thinking? Organism
from microbiology? Good. A gram negative organism.
For example, if a female was pregnant and
her urethra is rather small, she is now exposed
and she is vulnerable to infection such as E.
coli. Here comes the E. coli and it starts
to mountain climbing up the female's urethra.
Pleasant topic. And eventually, at some point
maybe there is pyelonephritis, oh! my goodness, this
E. coli and the urinary tract infection and
pyelonephritis wasn't properly discovered, ends
up resulting with septicemia, eventually result
in sepsis. This gram-negative organism with
lipopolysaccride, I am going through this quickly
because this is micro. The lipopolysacchride
and such then brings about all the cytokine
changes in which what then happens to our
blood vessel? Vasodilation and so now you will
have normal extracellular fluid volume, but
then you have a decreased ECV because things
are moving through this so quickly and there
is every possibility that some of this fluid
might just be able to move through, increased
permeable capillaries. But overall though, with
normal ECF clinically with a decrease in effective
Let us go to the third column. Here this is
the one that I mentioned to you earlier with
CHF, cirrhosis and nephrotic, put all three together.
Congestive heart failure, what is my problem?
I want you to focus about right-sided heart
failure to make it easier for us and I am
going to be more specific here because you
must understand the only time that you would
find peripheral edema and positive JVD is
what kind of heart failure? Right-sided heart
failure. Are we clear? Don't ever miss that
question. So right-sided heart failure, what
are you going to do? Increase hydrostatic
pressure, where is this fluid moving from? From the plasma,
which we call what? Effective circulating
volume into the interstitium, which is part
of your ECF. So, therefore, can we clearly
see as to how you are going to rapidly, I mean
literally you can see the patient with pitting
edema. You can clearly see as to how fluid
is accumulating in the interstitium in excess.
ECF is increasing and how can you confirm
that the effective circulating volume is decreased
because who is being released from the juxtaglomerular
apparatus of the kidney? Renin.
How is that possible? Effective circulating
volume is decreased. Talked about CHF. What
about cirrhosis? We have done this a few times.
If the liver has been knocked out, then what
happens to protein content? You never produce
the albumin. What happens to oncotic pressure?
It is decreased. Where is my fluid? Good.
Into the interstitium. How can you confirm
that? Look at the patient with cirrhosis.
Drink too much alcohol for years and years
and years and what happened? I used to be in
shape once upon a time, but now let us say
you are a rock star and maybe perhaps I am
just being stereotypical here and I went through
a period where I was drinking quite a bit,
and then all of a sudden now I sing like this.
I can't even see my feet anymore because of
my ascites, right. Cirrhosis, what does this
mean? Increase in extracellular fluid
volume. Are we clear? And what about nephrotic?
Most common cause of nephrotic in a child,
you will tell me minimal change disease. What
do you know about that child losing lots of
protein? Losing lots of protein. How much,
the magic number? Greater than 3.5 grams of
protein per day. What happens to your oncotic
pressure? It decreases. Where is my fluid?
In the interstitium. Could this table be any
more clinical than what it is now? You see
the clear difference between effective circulating
volume and ECF. If you haven't, you do now.
Let us move on.
Quickly go through some important physiologic
changes and give it a clinical application
with a Darrow Yannet box . First and foremost,
this box that we are seeing, I've set it up for
you, X-axis. If you haven't done it like this, do
it now because your life becomes so much easier.
The X-axis represents the volume. The Y-axis
represents the osmolarity. We have a line
in the middle there. That is the barrier and
that is separating the ECF and ICF. You tell
me what membrane that is. Close your eyes.
Be careful. It will come out your mouth. Okay.
You are thinking one thing, but something
else might either come out of your mouth or
you might accidentally choose it as being the
answer to it. Doesn't it happen all the time?
You go back and take a look at a question
and you are like why in the world did I choose
that answer. So let us avoid all of that.
Be deliberate with everything that you do.
So that barrier and that membrane that you are
seeing there ladies and gentleman is which
one? Is that the cell membrane or is that
the capillary membrane? That is going to be
your cell membrane. Good. And tell me about what
it's permeant to? Really water, that is about
it. Sodium? No, not the cell membrane. Are
you kidding me? But Dr. Raj, your sodium channels.
Would you stop being so hard on me? Yeah, that
sodium channel is not open. Understand that.
If that sodium channel is never opened, you
will not permeant to sodium. Clear? It is
that clear. It should be. It has to be. Otherwise,
your life becomes much more difficult and
you don't like that. Next, we are going to go
through volume contraction.
Now the steps that we had initiated a little
while ago was the following. So far, the first
thing that you want to do always, is always take a look
at what kind of change that I have in my plasma
compartment, which is part of your ECF. And
if that plasma compartment has decreased for
whatever reason, just take a look at diarrhea,
a wonderful topic. So when there is a loss
of fluid, you have ECF volume decreasing. Point
number 1. Let me show this to you here. The original
black square that you are seeing is being
a solid line represents normal, kind of like
what we started off originally with the control.
The dash line that you are seeing is going
to be the change. Here specifically in diarrhea,
I do not recommend that you memorize this.
You use these boxes as a conceptual tool in
your head so that when an attending or
when you are doing your rounds in the hospital
or you are taking a board exam, when people
pose questions to you, you have this image
in your head so that you can quickly come
up with the proper management of your patient.
So in diarrhea, you have lost obviously fluid.
Your ECF volume is going to decrease and what
axis here represents the volume? The X-axis.
Do you see ladies and gentleman that on the
X-axis, for the ECF, its volume has decreased? That
is your step number 1, always.
Next, what are you going to do? Well depending
as to what kind of loss that you have had.
You are going to have either an increase,
a decrease or no change with ECF. osmolarity.
Where is my osmolarity on this box, graph?
It is on the Y-axis. You'll notice ladies and
gentleman with diarrhea that there is basically
no change on the Y-axis. So your ECF osmolarity
remains normal. I doubt diarrhea is what we're doing
here and so, therefore, the type of fluid
that you have lost here without any change
in ECF osmolarity. What does this have to be? What
kind of loss? Good. Isotonic loss, okay. So
we will go through the details. All I am doing
here is just setting up the picture so that
when the time is right and we go through details,
we will be able to go through the material
efficiently. Let us go to the middle one.
The middle one, our overall theme for this
section is volume contraction and by volume
contraction, what do you begin first always?
That will be the ECF. Now you will go as far
as you need to say get your answer right.
So let us go a little bit further here.
Say it is water deprivation. What does that mean?
That means that the individual is deprived of water.
Why? Well, I'll give you an example. For example,
if there's psychogenic polydipsia, your primary polydipsia,
what is the one of the first steps that you
will do conservatively? You deprived the patient
of your water. But what if your patient is crazy?
I'm seeing things, I'm hearing things, auditory hallucination.
That is a psychosis. It is called a psychogenic
polydipsia. That patient feels as though he
or she needs to be drinking all the time. You
restrain that patient okay.
You have to do water
deprivation does. What is my point? What is
the water deprivation test? What is the first
thing that is going to happen? I am not drinking
water anymore. So, therefore, step number 1, ECF
volume is going to decrease. You are depriving
your patient of water. ECF volume decreases,
number 1. So what can you expect your ECF osmolarity
to do? As long as everything is normal, your
ECF osmolarity should increase now. Take a
look at that dash line in the middle picture
with water deprivation. Do you see the dash line?
And its ECF. Where is my osmolarity? Y-axis.
You see it rising. So now you have ECF osmolarity,
which is now increased. That is step number 2, always.
Now who is going to be influenced and who
is going to be affected? The ICF. Tell me
about the movement of water across what membrane
is this? Cell membrane. The movement of water
across the cell membrane. It goes from what
kind of movement? Diffusion. It will from a
place of low solute to high solute. Correct.
That is osmosis. Where is your high solute
right now? In the ECF compartment. How can
you confirm that? The ECF osmolarity. What happen
to your patient? Water deprivation. So far
so good. You are asking right questions and you're
come out with the proper solutions.
So, therefore, ICF, the water is being pulled
out into the ECF. What is step number 3 here?
It is the fact that ICF volume is decreased.
I can confirm that. Now take a look at ICF.
Take a look at the X-axis and take a look
at the dash line. We will notice that the
ICF volume has now diminished. Step number 3, as
ICF and its fluid is shifting into the ECF,
what is your fourth and final step which we
are now covering for the first time? It is
a fact that ICF osmolarity has increased.
How can you confirm that? Take a look at the
dash line and on the Y-axis, you find that
to be risen as well. Okay. What are my steps?
ECF volume, ECF osmolarity. ICF volume , ICF
osmolarity. Prime example while deprivation,
we needed all four here. Why didn't we need
all this for diarrhea? Because you lost what
kind of fluid? Isotonic fluid. Diarrhea out
it comes from your butt right and so, therefore,
isotonic loss all that you have affected is
ECF volume. Stop, that is all you have to do.
Why create more work for yourself? So be smart
about how you approach each patient, each
question. Let us move on to
Now this one is a little tricker, but I know
you can do this, in fact you have no choice.
So adrenal insufficiency, what then happens
here? Good. My question is, who has
been knocked out? The adrenal cortex. Primary
adrenal insufficiency, give me the proper
clinical name. Mr. Addison right, Addison's
disease is what this is. Good. In Addison's
disease, adrenals are not working properly.
If you are dealing with volume, would you
tell me what hormone is in play? This has
nothing to do with cortisol. Okay. Let that
go right now. When the time was right, of
course, we will talk further about that. Right
now, it is aldosterone that is not present
right. The entire adrenal cortex has been
destroyed, how? Maybe autoimmune disease.
Okay maybe idiopathic, what have you? So now
you don't have aldosterone. Work with me.
Remember all those discussions of aldosterone
that we have had up until now. That's gonna
come into play. In adrenal insufficiency we
don’t have aldosterone so therefore down
the collecting duct, you cannot reabsorb sodium
and so therefore it remains within my collecting
duct. So therefore what you are losing? Lots
of sodium. Lots of sodium is being lost and
along with sodium what is it going to do?
It is going to pull water out too. Fascinating.
So losing all this volume, what's your first
step always? ECF volume. Take a look. Where
is my volume? X-axis. Good. Take a look at
ECF. ECF volume is decreased. Excellent
Stop, why? Need you to think
okay. Please think. Watch this. You are losing
lots of sodium. Where? Into the toilet. There
it is. It is my sodium being flushed down
the toilet. It is not in my plasma. So tell
me about your plasma osmolarity when you are
flushing your sodium down your toilet. What's
your step number 2? ECF osmolarity. Why is it decreased?
Because you are flushing your sodium down
the toilet. You see that. Interesting. Compare
this to water deprivation. Compare this to
diarrhea. We will compare this to a lot. So
here you are losing your urine. Fine. You
are losing lots of sodium. You find that your
ECF osmolarity has decreased. Take a look
at the dash line please. Take a look at the
Y-axis. You see that to be decreased as well.
We're at next step number 2. You tell me. What was your
third step? ICF volume, good. So now you have
a decrease in ECF osmolarity. Which way does
your water want to go? Where is your more
solute? In the ICF, right. Good. Water is going to
shift into ICF. So what happens to
ICF volume? Now do you see how things have become easier?
ICF volume has increased. How can you confirm
that? Take a look at the X-axis and you find
the dash line, the ICF volume has increased.
That is step number 3. And finally as more volume and
fluid in my ICF, what would happen to my ICF osmolarity?
Good. Y-axis, it is decreased. You see this.
You firmly implant these concepts of these
boxes with those four steps every single time.
There is no way. At least you will be able
to get the foundation and then from that you
can administer proper management.
Now the bottom portion here is going to be
volume expansion obviously we are not going
to spend as much time going through every
step. So I'm going to fly thorugh this, but you
will be able to stick with me. Ready. The only
way you want to do this is you have understood
everything up until now. Let's do infusion
of strict isotonic saline. Isotonic
saline. What is the only thing that is going
to happen? Here's your patient, what did he or
she suffer from? Hypovolemia and as soon as
your patient comes in, what are you going
to give? Isotonic saline IV fluid. Step number 1,
ECF volume increased. You are done. I don't
even care about the other steps right now.
Let it go. Let us go to high NaCl intake.
What is this? Maybe patient taking antibiotics.
What is NaCl? No. Listen. High salt
only. What is the difference between high
salt versus the first one? Take a look at
the terminology. Isotonic saline is IV fluids.
Strict NaCl is only salt tablets. If all that
you are doing is strictly putting salt into
the system, what are you going to do immediately?
ECF osmolarity increased, thus it is going
to pull the water out and as which we
are seeing here, you are done.
Let us move on to SIADH.
SIADH could be a little tricky, but you are good.
I'm going to give you some examples. Let your patient
has had a posterior pituitary issue in which there
is producing too much ADH maybe a patient
has small cell lung cancer. Small cell lung
cancer of what? The lung. And you are releasing
too much ADH parineoplastically and you have
too much ADH, what then happens? Step number 1,
pulling too much water out of your collecting
duct, strictly, what kind of water? Is that
free or obligated, please? Free. If you are
pulling water out, what happens to your ECF
volume? Step number 1, increased. Step number 2, ECF osmolarity
decreased. Step number 3, what is going into the
cell? ICF volume, increased. Step number 4, ICF osmolarity,
decreased. You must do that quickly and you
will get there if you haven’t already. Fantastic.
Let us move on. Now after that, things become
more interesting clinically, okay. What I wish
for you to focus upon here is the same box
the same issues in terms of the X-axis, Y-axis?
I am not going to cover that again, but what
I wish to cover is D5W. Okay. What does that
mean to you and when would you even think about
giving this? D5W is strict pure water.
Dr. Raj, it says D5W, how can that be pure water?
Listen, clinically, this is equal to pure water.
Why don't you just give pure water, Dr. Raj?
Because listen you got this. If you put pure
water into your patient, oh! my goodness,
the water is going to do what? It is going
to equilibrate throughout the total body
water. Really quick. What you are worried
about when you put too much water strictly?
It is going to go straight into the cell.
What don't you just kill your patient? Just resign
from your job. Leave now. Never practice medicine,
please. Don't do that. So you are not going
to infuse pure water. But say that you have
a situation that you need to give hypertonic
fluid, D5W. What is it going to do? Listen.
This is dextrose 5 percent with water. What
is dextrose? Think of it as being like glucose.
Listen to this. You have done this in physio.
Let us do it now clinically. If you have glucose,
at first if you infuse it and along with it
attach to the water. So this is pretty
much obligated water and you want to give
hypertonic fluid for whatever reason in your
patient. And so now you want to retard, you
want to delay that water from entering the
cell, don't you? D5W will help you do that.
D5W, the 5 percent dextrose is just enough
in which it will delay the entry. Take a
look of that water into the ICF so that you
do not have swelling and bursting of your,
you don't want fireworks in your plasma. Trust
me. So you don't wan tto have excess swelling and
D5W accomplishes that exact task. Now we have
ICF contraction. This will be what kind of issue? Give
me condition in which your volume from the
ICF is being pulled out into the ECF. Take
a look at hypernatremia or excess let us say
glucose, uncontrolled diabetes mellitus.