Today our topic brings us
into the analysis of urine
How important is this?
With urine analysis, we'll take
a look at general examination
we'll take a look at the
various types of dipsticks
Yes , I said various
types of dipsticks
that are important for
us to then measure
whatever metabolite that we're
looking for in the urine
Is that clear?
Now I understand that sometimes
when you do a general dipstick,
that you may or may not find the
chemical that you're looking for
based on the suspicion of the diagnosis
that you're making for your patient
So how do you know
which dipstick to use?
So all that you're doing in this
section as we go through urinalysis
and the different
types of dipsticks
It is important that you understand,
well the history comes first
then use this information that you're
given from urinalysis as either
confirmation or to complement and support
the diagnosis that you've come up with
we'll take a look at the sediments
and their various morphology
of that that you find within
the urine when we analyze
Now each one of these terms
that we then find in the urine
well, you've heard
of cast before
you've heard of different types
of cells such as WBCs and RBCs
all these becomes
really important for us
But as I said, at first it's
about the pathophysiology
Making sure that you have your foundations
strong before we even take a look at urine
Now, this table.
There are a few tables that we'll be
looking at in this lecture series
And there will be overview
to spend a little bit of time
to make sure that you understand each one
of the statements that I'll be making
So let me walk you through this
First component of urine on general
examination that you will be conducting
or you will be given in terms of
information either from notes
from SOAP notes, or perhaps
from your question
Well then, have you
determined or well,
how do this occur
in terms of color?
If it's a dark yellow,
maybe concentrated urine
So therefore, tell me
about your patient.
Maybe perhaps, dehydrated?
Maybe there is excess sweating?
And remember as to what
happens in excess sweating
There is hypotonic loss of sodium
and so therefore what's
your plasma osmolarity?
If your plasma osmolarity is
increased, then now you tell me,
Based on lecture series at this point, these
should be reflex answers, aren't they?
If they're not, then maybe perhaps
go back and lay down the foundation
When your plasma osmolarity is increased,
then you'll have your osmoreceptors
up in the hypothalamus releasing ADH,
down they come to the collecting duct
Now what do they do?
They then remove that fluid and water
from your collecting duct
resulting in what kind of urine?
A concentrated urine.
What color is this? Dark yellow.
Let's move on.
What if you found bilirubin?
Completely different story, isn't it?
completely different story.
In hepatobiliary pathology,
we will have done
well, issues with jaundice
So therefore, we'll take a look at
prehepatic, hepatic, posthepatic jaundice
and what it means for you to actually
find bilirubin in your urine
Now there are different types in
biochemistry you have already discussed
What bilirubin metabolism means
and what type
of bilirubin you should be finding in urine
versus that type of bilirubin which
then indicates a pathology
so for example, when you get the
bilirubin down in the intestine
at some point, you go
through various mechanisms
in which you finally form
some of that urobilinogen
The urobilinogen will then contribute
to the pigmentation of our stool
Did you see your stool this morning?
What color was it?
That was brown -
or when you took urination or you went
pee, then what color was your urine?
Oh it was yellow, or golden. And
that's a type of urobilin, isn't it?
But ultimately, there are other components
of bilirubin such as conjugated bilirubin
and if that ends up in your
urine, that is a pathology.
and that is something that we
have discussed in hepatobiliary
and so therefore the color of that urine
here in fact would be dark yellow
Increased UBG would mean urobilinogen
and what that basically means
is that say for example, you're
not able to properly, let me..
Let me ask you something,
are you ready?
Now if you get something
into the intestine,
is that then going to
end up in your urine?
Once again, if you get a substance in your
intestine, this is just simple physiology
but this is where students go wrong.
If you get something
in your intestine,
how in the world is that
gonna end up in your urine?
if it ends up in your intestine, ends
up in your stool, I'll give you that
But in order for you to get something
in your kidney, and this is important
Then you have to reabsorb that substance
from the intestine into the plasma
and then the plasma goes to the
kidney and then it gets filtered
only then will it end
up in the urine, right?
So whenever you find
It only means that there's excess amounts
of this in your blood or in your plasma
It is only then that it gets filtered, so
maybe perhaps there is blockage of what?
Maybe there's some
kind of hepatic obstruction
And if there's some type of
biliary obstruction then
the only method out from your
liver would be into the plasma.
Keep that in mind.
Now, so this is just
one statement in which
there's all this understanding
that took place
prior to you actually examining and
analyzing urine for urobilinogen.
What about vitamins?
Well as far as vitamins are concerned,
what kind of substance or or what kind of
characteristic does a vitamin have
to have for it to be in your urine?
It has to be conjugated, it has
to be water soluble, doesn't it?
And so that then becomes
important in terms of let's say
that you take Vitamin C,
or vitamin B vitamins
Some of those are water soluble but
could they then end up in your urine?
Quite a bit actually.
So all those vitamins that
you end up taking, remember
a lot of those if you don't require
it, they end up in your urine
gets reabsorbed into your plasma
and then it gets filtered
dark dark yellow
color, number one.
A second type of
color - red or pink
what does this mean? The
urine actually looks red.
For example, you wake up in the
morning and that first micturition
that first micturition,
passing of urine
Oh my God, it's red!
How did that happen?
It's gonna scare you for
the patient isn't it?
How in the world did you end up
getting blood in your urine?
well that one that I just gave you
where you wake up in the morning
Well what happened
that night perhaps?
Your respiratory rate,
increased or decreased?
Let me walk you through this
Decreased respiratory rate. huh?
You're holding on
to carbon dioxide.
So for that moment at night then, what
is your pH? A little bit decreased,
It's called a respiratory acidosis.
So at night, you go through
and then all of a sudden, the RBCs are
undergoing severe intravascular hemolysis
so all of these, comes into
well not so much simple
but you're strong
the time that you spent
understanding a condition
In paroxysmal nocturnal hemoglobinuria,
the problem is genetically
in which the complement system ends up
destroying your RBCs intravascularly
in conditions that are acidotic.
welcome to "nocturnal" - at night
you wake up in the morning,
we find your urine to be,
well that's the patient himself or herself
that ends up seeing the red urine
Hematuria, that's what this is.
then we have hemoglobinuria.
what does that mean to you?
well this is something like
in which you are literally losing
hemoglobin through your glomerulus
and this is an example
that I gave you such as
All I'm doing at this point is
giving you a little bit of history
based on some of the findings that you
might have based on the color of urine
What if it's myoglobinuria?
How'd you think about this,
or how should you be
thinking about this?
myoglobin is the hemoglobin for
the muscle hence, myo- right?
and so therefore say that you
get into a crush injury
and if there's a crush
there's a damage through
the skeletal muscle
in which you are then releasing
myoglobin into the plasma.
and that then ends up in the urine,
what do we call this?
what color might these then give your urine?
red or pink
Drugs such as phenazopyridine or urinary
anesthetics possibly and then porphyrias
the big one here, you might have heard
of acute intermittent porphyria.
acute intermittent porphyria, a porphyria
in which many of the symptoms and signs
that you find with AIP would
begin with the letter "P"
meaning to say that you will
end up having pink urine
there'll be "abdominal Pain",
there is (P) "psychosis".
Let's take at least 3 Ps right now,
for acute intermittent porphyria,
one of them being "pink urine",
Do you see the significance
of urine analysis thus far?
You thought that you could just
go through this and memorize that?
you know me well enough, well
that's not what we're gonna do
It's about you looking at this, seeing
this, hearing this and truly coming up
with a few differentials in your head
as to what's going on with your patient.
what if it's smoky colored urine?
urine converts the hemoglobin
into what's called "hematin"
and a common finding
and if you're dealing with nephritic
you should be thinking something along
the lines of perhaps IgA nephropathy
why did I say IgA nephropathy?
Because that would be the most
common type of glomerulonephritis.
So nephritic, what does that mean to you?
You pay attention to letter H
and a lecture series that we have together
in which we talk about glomerulonephritides
and we talked about
I will have you highlight in your
head the leter "H" for nephritic
why? that "H" means,
It could mean that you
have smoky colored urine
Hematin is what you're
paying attention to
What if it was black urine?
That's crazy, isn't it?
could you imagine urinating and then upon
exposure to oxygen and the environment,
it turns black?
What's your diagnosis?
Well this could be something like
alkaptonuria, autosomal recessive disorder
with a deficiency, and you must memorize,
and you have memorized in biochemistry,
the enzyme called homogentisate oxidase. Homogentisate oxidase is the enzyme
that's deficient in a
condition called alkaptonuria
now that you find as being
black, what happens? take a look
it's a homogentisic acid in the urine,
and therefore upon exposure to light
as soon as it comes out into the world
as urine does, it then turns black
and some of those black
substance may also accumulate
with the new cartilage and
such called ochronosis
We talk about clarity.
so one major component that we just
completed our discussion, is color.
what about clarity?
What if it's cloudy urine?
this is alkaline pH,
so what does this mean to you?
normal finding, most often
due to - phosphates.
What if it's cloudy urine with acid pH?
normal finding most often
due to - uric acid
so you wanna be familiar as to what the
pH of the urine is in great detail
In general, it tends to be on the acidic
side, but if it's a little bit more acidic
say that it's below 4.0,
then you start thinking about uric acid
if it's on the higher side,
maybe 5.5 and maybe 6.0
then you're thinking along
the lines of phosphates
depending as to what the physiologic
needs of the patient is
then you have others, others in
terms of clarity, bacteria, WBCs
we will be focusing upon these as we
progress further through urinalysis
do you see now it's to how we
create a picture of a table
and the more number of times that
you're able to give clinical tags
and let me give you a
tidbit of advise here
it is not imperative at this point for
you to go through every single detail
and don't get frustrated if you're not able
to come up with a differential immediately
at least pick one or two components
of each one of these characteristics
if it's dark yellow, at this point if
all that you can remember is bilirubin
Okay it's fantastic, it's okay at least give
yourself one tag of a differential, right?
if the only thing that you can, at this
point, remember what pink
as being a symptom
that's okay, you keep coming
back, you keep coming back
everytime you come back,
you give a clinical tag,
you give a clinical correlation
with each one of these findings
and before you know it, you have
a whole host of differentials
You do that throughout
medicine with me,
and you will be in fantastic
shape when it comes to pathology
Another component would be
What's this mean?
literally, the gravity that
the urine is exhibiting,
concentration and dilution
now before we move on, if your urine's
concentrated, what color is it?
Next, if your urine is concentrated,
what do you expect the gravity to be?
use common sense here,
Obviously, it will be increased
Let's take a look.
If your specific gravity is above, now
this you'd want to memorize, 1.023,
the usual limit of specific
gravity is usually by 1.010
What I mean by that is 1.010
Use 1.010, How would you say that
in layman's terms?
say "10.10" make your life easier
now here we have something
that's graded 1.023
that's high specific gravity.
next, well okay that sounds good
but what does that actually mean?
responsible to do what?
you're responsible to
actually interpret labs
in your hands maybe on a
computer screen, what have you?
and you should be able to take
a look at urine osmolarity,
take a look at what's
in the parenthesis here
urine osmolarity at
may I ask you something?
what's normal plasma osmolarity?
normal, approximately 300 mOsm
when you get this plasma
into the Bowman's space
and the proximal
portion of the PCT
which of the urine
osmolarity approximate? 300
Ah, what's my point?
If you start moving down to descending
limb, you start raising urine osmolarity
doesn't 900 seem a lot more
dramatically increased than 300? it is.
is 900 concentrated or
diluted urine, please?
It's concentrated urine.
which is specific gravity?
understand the concept first
then you put in the values
indicates urine concentration and
excludes the intrinsic renal disease
excludes it. why?
that means that ADH
had an opportunity to remove the water
and thus increase concentration
so we have hypotonic urine - has a specific
gravity of 1.015, what does this mean?
Don't memorize this either,
understand the concept first
hypotonic urine, what kind of
urine is this? it's diluted urine
did ADH work yet? Probably not.
Because you created diluted urine
the urine osmolarity, take a look at
this, what's normal plasma osmolarity?
approximately 300 mOsm,
and then you get them
to the Bowman's space,
what is the urine osmolarity there?
Approximately 300 mOsm
take a look at urine osmolarity in
the parenthesis, what does that say?
320 mOsm in the urine
What does that mean to you?
what do you call that in layman's terms?
what is the specific gravity?
understand the concept, then
you memorize less than 1.015
Let's move on..
Urine osmolarity is the best indicator
of urine concentration or dilution
We just went through examples
here of showcasing that
Next, what if it was a fixed specific
gravity, okay so then we have here
let's say that it's fixed at approximately
normal, and we'll use 1.010
correlation with urine osmolarity,
lack of concentration and dilution
This indicates chronic
I want you to come back up and
take a look at the second row here
and while we're talking about specific
gravity being greater than 1.023
that is concentrated urine.
What does that do?
that excludes intrinsic
But if your urine osmolarity is
fixed throughout the nephron,
Do you understand the concept?
Nothing is changing.
Why? because the kidney is dying
Do you understand how
important this is?
Example, chronic renal failure.
How important is this?
How often does this occur?
Have you heard of diabetic nephropathy?
it occurs more often
than when we think, huh?
specific gravity. We spent
a little bit of time here
Understand the concepts
in putting the values