Okay, so bilirubin we've talked about
earlier when we were looking at the color
What color is that going
to give you, your urine?
Well that, for the most
part will be your yellow
Now, the discussion here
for dipstick - bilirubin
detects conjugated bilirubin
So Dr. Raj, I thought you just
told me that you'd find bilirubin
in your urine and in your stool?
You even told me to take a look
at my stool from this morning
which you said was brown.
Yeah, that's exactly what I told you.
But why did I tell you to do that?
Because that type of bilirubin is
your urobilin or your stercobilin.
Is that the conjugated bilirubin?
Now at this point if you feel completely
lost about bilirubin metabolism
Guess what, this would be a good time for
you to review your bilirubin biochemistry
We don't have time right now
So, I'm telling you this
If you find conjugated bilirubin
in your urine, this is a problem
This is a pathology, so now let
me give you a differential.
What if you had liver damage?
What if you had some type of obstruction
known as choledocholithias?
Say that three times fast, it's
actually kinda fun.
Do it: choledocholithiasis.
or you have liver damage.
Isn't that fun? Come on now, let's
have fun with that information.
So now, you cannot, now
listen, now we'll get serious
That bilirubin now
has been conjugated
You know that conjugating
enzymes are in the liver
You know about UGT, or UDPGT,
it's all the same thing
But it undergone the process
Okay so if you're conjugating in the liver
and you don't have an enzyme
supply problem in the liver
Then you are conjugating
your bilirubin, are you not?
Yes, you are.
That conjugated bilirubin
should end up in the bile
and then eventually
in the intestine
and then through the process
of bacteria and such
will then form your different types of
bilirubin: either urobilin or stercobilin
And that should end up in your
stool and your urine, respectively
But what if you couldn't get that
conjugated bilirubin out into the bile
What are you forced to do?
What did I tell you earlier
How do you get something
in your urine?
It has to be filtered from the
plasma, are you picturing that?
It has to be filtered from the plasma
If you just have something in the
intestine, I'd give you the stool,
but it won't be in the urine.
Your kidney doesn't filter the
intestine, it filters plasma.
It's a conjugated bilirubin if
it's forced to go onto the blood
either due to through obstruction
or maybe liver damage
Then what are you gonna find
in urine, pathologically?
Are we clear now?
It has to be conjugated bilirubin
But Dr. Raj, why not unconjugated
bilirubin or indirect bilirubin?
Because that'll give you your
discoloration, yellow skin- that's jaundice
because that's lipid soluble
So in order for you to understand the
significance of conjugated bilirubin here,
You must understand the biochemistry and
physiology for all this to come together
Bilirubinuria: viral hepatitis,
Voila! there's your differentials
But guess what, you already predicted that
because that's exactly what we discussed.
You can't memorize this, how
many times have I said this.
But it takes time to understand,
but don't get frustrated.
Keep coming back, a tidbit, just
a little bit every single day
Consistency, digest it. Trust
me, it will become a party.
to have trace amounts.
Normal urine color is due
to, there it is, urobilin.
Are we seeing this?
Now more importantly,
urobilin is different from
our previous discussion
just now, of conjugated bilirubin
Conjugated bilirubin to you,
Oh, maybe there's liver damage.
Oh, maybe there's obstruction.
Urobilinogen, yeah the urobilin should
be normally present in your urine.
Stercobilin in your stool.
Now, absent urine urobilinogen increases
or if you have absent urine urobilinogen,
you're thinking about obstructive jaundice
and if you find increased
Okay see how these terms
sound very much alike?
Urobilinogen, it's trace amount should
be normal. Bilirubin should not.
If you're obstructed,
give yourself an example.
such as a stone.
If you have a stone in your biliary tree,
can I get my bilirubin into my bile?
No, you cannot.
Where are you forced to go into?
Tell me, I need this from you.
You're forced to go into your blood,
you're forced to go into your plasma.
See if you find increased urobilin
or bilirubin, that is not good.
something like choledocholithiasis
Next, increased urine urobilinogen,
absent urine bilirubin. What's this mean?
extravascular hemolytic anemia.
Wow, what are we doing here?
We're putting out this is an examples of complete
integration of various systems as we're seeing
Give an example of extravascular hemolysis.
Who's this patient?
Young guy, african american boy, running,
likes to play, is on the track team
while running, all of a sudden stops and
feel pain in the chest and in the fingers
You take a look at your patient.
Well, the patient, kinda
difficult to find the jaundice
But right around the eyes, there's
icterus in the mucosa, icterus.
Who's your patient?
sickle cell disease.
I gave you an African boy who's running,
feeling pain in the chest, pain in the fingers
What is this called?
It's called cclusive crisis.
Microvascular occlusive crisis,
acute chest syndrome.
What's this called in the hand, the pain?
Is this intra or extravascular hemolysis?
Take your time.
The spleen is destroying the
RBCs in great abundance
This is extravascular hemolysis.
Another one, they're also falling
to the category of extravascular,
Take a look at your example,
Two differentials for extravascular.
What's happening here?
You are releasing your RBC and
bilirubin at great abundance
This bilirubin, unconjugated ends up in
the skin, gives you jaundice no doubt
This vast amounts of bilirubin
also will arrive at the liver
You are going to conjugate this
Look at this, any problems with the
liver and extravascular hemolysis?
No, no, no.
Maybe have issues in spleen later on
That's a different discussion.
But the liver is conjugating,
conjugating, conjugating, conjugating,
everything that it's getting,
it's trying to conjugate.
So therefore, how much urobilinogen
do you have in your urine?
Do you have obstruction with
extravascular hemolysis? Yes or no?
So therefore, you have
absent urine bilirubin.
Your objective at this point?
Stop here for a second.
And I need you to take a look at this
discussion, with the discussion right above
where we talked about absent urine
urobilinogen and increased urine bilirubin
Do you see as to how after 6 hours,
7 hours, 8 hours of taking exam
you're on your rotation, you are tired.
You might be tired now and I only
spent what, 15 minutes with you.
and then on the 6th hour, you're
supposed to think like this?
where all your terms should
be absolutely perfect?
Yeah, that's how alert
you need to be.
Is it stressful? It is. But you need
to spend time is what I'm saying.
and understand this.
Increased urine urobilinogen,
increased urine bilirubin.
this should be a mixed picture and this
would be something like hepatitis.
so this would be another
section of urobilinogen
and walking through the different components
that becomes really important discussion
take a look at the second
column, what's this category?
You notice it doesn't say "memorization".
is that clear?
That's what these are!
These are discussions.
And once you get this done,
you can have a conversation
with any doctor, at any point in
time, and you will not feel foolish