Hi, welcome to our video series on interpreting lab values.
In this one, I'm gonna dig a little
deeper into BUN or blood urea nitrogen
because I want you to
understand where those come from.
Alright, don't panic, I know
you see a molecule up there.
When I was in chemistry class, I used
to break out in a sweat when I saw that.
I have a reason, there's a method to
my madness in walking you through thi.s
All nurses need to understand where BUN comes from.
So nitrogen in the blood that comes from your urea seems
pretty simple but I want to walk you through the steps.
You have a very clear understanding,
I don't want you to have to memorize,
I want you to understand
what's going on behind it.
So let me talk to you today about the
urea cycle, okay, you heard me - cycle, C-Y-C-L-E
Here's what goes down.
Ammonia is a highly toxic waste
product - you already know that
but too much of it in your body,
we're gonna have some big problems.
Here's how the urea cycle help us with ammmonia,
because ammonia happens when protein is broken down.
It can't get rid of that in our body unless it's
converted to urea and that's this cycle - the urea cycle.
The urea cycle helps us take that toxic ammonia,
break it down so we can get rid of it from the body.
Now it takes this whole cycle of
biochemical reactions, so stay calm.
If you're a chemistry nerd quit picking on us, if you're
like me and chemistry was really hard for you, hang with me
I'm gonna get you to where you need to go.
Now these are the normal values.
Right, normal is 7-20 (mg/dL),
that's the value we use for this series.
The high range is when we're really
talking about our patient is in trouble
Now again we've got a long list there
and you know how I feel about lists.
My brain can't remember those but I know three main
things I think about when it be when the BUN is elevated.
I think about organ dysfunction
- both the liver and the kidneys.
I think about excess protein which could be
upper GI bleeding or high protein intake in my diet
or I think about significant dehydration.
So any time I see a high BUN, if the
organs weren't working, I've got extra protein
or I'm significantly dehydrated, all
those will cause my BUN to go up.