Hey there friend, I'm Christina Rafano from nursingschoolofsuccess.com and in this video
we are going to talk about cretinine clearance.
Yeah, I know you're confused by it, because I was too in nursing school.
So let's break it down.
And be sure to stick around until the end of the video because I've got a free lab value
cheat sheet to help you out with lab values in nursing school.
Alrighty, so creatine is just a big fancy word for trash.
Okay, it's not exactly trash, but it is trash.
It's just a waste product that your muscles make when they work hard all day.
So as you move around, and go throughout your day, your muscle cells are constantly building
up and breaking down in order to stay healthy.
And when muscle breaks down, it releases creatinine.
So creatinine is just a waste product of muscle metabolism.
That's all it is!
Now here's where things get interesting.
The kidneys are fully responsible for getting rid of all of this creatinine.
So they're job is to take it all out of the blood and excrete it into the urine.
So, let's walk through some critical thinking.
What do you think will happen to the creatinine level if the kidneys are damaged?
Will they be able to get out as much creatinine from the blood as they were before?
No sir!
If they are damaged, the kidneys can't do their job as well to get rid of all that creatinine,
so the creatinine level will build up inside the blood.
Now, this is why we measure creatinine clearance, it's primarily to check for kidney function.
So creatinine clearance is mostly a test of the kidneys, it tests the glomerular filtration
rate, meaning, how long does it take for the kidneys to get rid of all that creatinine?
So creatinine clearance is a really good test for kidney function.
It shows us how well the kidneys are doing.
Alright, so typically how we test for this is a 24 hour creatinine clearance test.
So over the course of 24 hours, you'll collect the patient's urine.
Now here's a KEY POINT, you've gotta know this for nursing school, it's almost guaranteed
to show up on one of your exams somewhere: when you do a 24 hour urine collection, you
MUST have the patient void FIRST before you start, and then 24 hours later, you need to
collect that last urine right at the 24 hour mark.
So, when you go to start the creatinine clearance test for a patient, are you going to walk
into their room and collect their urine right then.
No!
You're not, because the 24 hour clock hasn't started yet.
You will need to have them use the bathroom FIRST, and then that starts the 24 hours and
you'll collect all of their urine for 24 hours.
You're just trying to get it as precise as possible within that 24 hour time frame, and
if you collect urine that they made BEFORE the 24 hours started, the results would be
off.
So that's why this is super important!
Typical creatinine clearance is between 90 and 120 mL per minute, roughly.
Of course, it varies for men and women, and it may also decrease with age.
And there are some things that increase and decrease the creatine clearance value.
So let's walk through some critical thinking with these ones as well.
Creatinine clearance may increase if someone eats a whole lot of meat and protein, or does
a lot of weight lifting, because that's building up muscle and the creatine levels inside the
blood, so obviously, creatinine will be higher, and therefore the creatinine clearance will
be higher.
Now a decreased creatinine clearance would happen in kidney disease or kidney impairment.
Because like we said before, if the kidneys are damaged, they can't do their job.
And because their job is to get RID of creatinine, if they're damaged, they can't do that.
So that creatinine clearance value would decrease.
The same goes for dehydration, where the kidney just isn't getting enough blood flow or there's
just not enough fluid to pass through into the urine, then you might see the creatinine
clearance be a little lower as well.
So basically, if the kidney might possibly be impaired in any way, most likely, you'll
see a decrease in creatinine clearance.
And that is creatinine clearance.
Now I put a link in the description below this video so you can download your free cheat
sheet.
Be sure to check out the other videos we have for you to help you out with lab values and
med-surg nursing.
And as always, hit that like button, share this video with your friends who might also
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Thank you so much for watching friend.
Now go become the nurse that God created only YOU to be.
I'll catch you right back here next time, on the nursing school show.
Take care.