Now we're going to look at serum creatinine.
Now creatinine is another waste product.
Creatinine is the waste product of creatine
like muscles use creatine to make energy.
So if you've been at the gym,
you see a lot of people add and creatine to their stuff.
Right?
But creatine is the muscles use that to make energy.
When the muscles use creatine you end up with creatinine.
Wow, those names are closed.
So you might need to pause the video
and go go over the a little bit
but serum creatinine is looking
at the creatinine level in your blood.
So creatinine is a chemical waste product
and it's produced by muscle metabolism.
Now healthy kidneys can usually get rid of this.
They can usually filter creatinine
from the waste products and other waste products
from your blood into your pee.
That's what it does.
So we know creatinine it's a chemical waste product.
It's produced by muscle metabolism
from creatine that they use for energy
and normal healthy. kidneys can filter this
out of the bloodstream and pee it out of their bodies.
If the kidneys are limping.
They're not doing well.
Then we're going to have elevated serum creatinine levels.
Because they help us assess renal or kidney function
and pair of kidneys lead to higher levels
of creatinine in the blood
because the folk the kidneys can't filter it out of the blood
and deposit into the pee to be excreted out,
you end up with higher levels remeaning in the blood
when we do a serum creatinine test,
your drawing blood usually from a venous sample.
And so that's why we can measure
that there's a higher level of creatinine in the blood.
Now serum creatinine can also help give us an estimate
of how well the kidneys are able to filter.
Okay, hang on, because this part gets super cool.
Now you see we have over there for picture of what?
That should look familiar to you.
Yeah, it's the glomerulus.
Look at that.
You got the blood supply coming
in the tangle of capillaries that's the Glomerulus.
It's surrounded by Bowman's capsule
that will lead down to the tubules.
That is some cool kidney stuff. Right?
Well, it's much easier to estimate
the glomerular filtration rate.
If I'm healthy,
there's some numbers that I can know GFR
but as the kidneys begin to have trouble
that GFR is going to be lower and lower and lower.
So the Serum Creatinine,
will tell me what the creatinine level is
in my blood and if the kidneys aren't functioning well that's going to go up,
and also the serum creatinine is used
to do the estimate of the glomerular filtration rate.
Now, there's normal levels of serum creatinine
and I know you're not going to be super excited
because you see there's two values for this.
It's because males have one normal value
and females have another.
Now they are pretty close
so you can figure out how you want to memorize those.
But just remember males are slightly higher
than females on our slide.
It's like .1 higher, right?
so you can memorize one and no it's either just .1 higher
or point one lower.
Whichever one you want to memorize
because this is a very important test of both kidney function
and helping us calculate glomerular filtration rate.
Now, what are some reasons for high creatinine
we've talked about some
but I want to give you some major examples.
So if I have a patient who has Chronic Kidney Disease,
I would anticipate a relatively high creatinine
if they have kidney obstruction.
Whoa.
Well, remember we're trying to get the creatinine
out of the body through the urine.
So if there's an obstruction
or not letting enough urine of the body
that would make sense why creatinine would be high
if someone is really really dehydrated
both their BUN and their creatinine will be elevated.
So watch that
if I have a patient I know is really intravascularly dehydrated,
I would expect there BUN and creatinine to be high
when we rehydrate them when we fill up their tank again
intravascularly their volume is more imbalance,
so they've got more in their veins and arteries,
you'll watch that be you in and creatinine come down.
Now it could also be the patient is eating
extremely high amounts of dietary protein
that may or may not affect the patient.
It just depends on the individual patient.
But if you think about it,
you got the issues with dietary protein
that might be another cause of high creatinine.
Now here's a here's a killer one.
Intense exercise, If you've got someone who's an extreme athlete
who's doing some really tough workouts,
you might also see higher creatinine levels
the kidneys may be fine.
The reason for the high creatinine is
because of the Extreme Workout.
There's also some medications that can cause it so.
Okay, that was a lot of information.
Let's walk back through it again.
So you see underneath the kidney.
They just have kidney disease or kidney obstruction,
that's going to be high creatinine.
If they're dehydrated
or eating high levels of dietary protein
that could also cause it.
That's why you've got a glass of water next to a big fat steak
unless you've got this guy who's running away
from Angry pills that are chasing him.
So that will help you remember intense exercise
or certain medications.