Now, hypotonic solutions.
See, D5W is a great introduction to these.
Remember, hypotonic solutions cause fluid to shift from the blood vessels into the cells.
So we've got the graphic there, the great picture to remind you.
So it moves from extracellular to intracellular when you hang a hypotonic solution.
So someone who already has elevated intracranial pressure, not a good choice.
So people who have head traumas are likely to have elevated intracranial pressure
that's why you wouldn't wanna give this solution.
Same thing for someone who's had stroke or neurosurgery.
Now, third spacers.
People who've got significant burns or trauma or have a low serum protein.
Again, these are not the solutions of choice.
So as a group, we're looking at the hypotonic solutions.
There's some of the examples listed there just to remind you of the names.
Same thing as you saw in our giant summary slide.
Now, let's take a look at some individual examples.
You'll hear us call this IV fluid half normal saline.
Technically, it's 0.45% but we often call it half normal saline.
Now, we can use it for DKA.
You notice I put some notes for you there about we use it after saline and before dextrose.
That's because we use more than one solution in treating diabetic ketoacidosis.
Just wanted you to be aware that this is one of the solutions we use.
We can also use it if someone's had intractable vomiting, nausea and vomiting,
or long-term NG suctioning.
The effect is the same. This would often be a fluid that we would choose for that.
And lastly, we can use it for hypertonic dehydration.
So you got water loss is greater than the salt loss. So those are 3 examples.
Kind of unusual ones.
You won't hang as much half normal saline in your career as you will the isotonic solutions.
Be careful not to use this with burns, liver disease, or trauma patients.
So that's a really important point that you remember this hypotonic solution,
you don't want to use it with burns, patients with liver disease, or who've had a trauma.
Okay, now we're to the last of the 3 sections, right?
We've done isotonic, hypotonic, now we're in hypertonic.
This is gonna cause fluid to shift from the cells and the interstitial spaces into the extracellular fluid.
So fluid is gonna come from the cells and the interstitial spaces
and into the extracellular fluid. So we can use this to replace electrolytes.
After surgery, this is a really good idea because it helps us with the risk of edema.
So if I'm causing fluid to go from the cells and the tissues into the outer space,
where is it going? Right, the intravascular space.
So I'm gonna dump that fluid into my intravascular space and healthy kidneys
should be able to help my body get rid of that fluid.
After surgery, that's how it helps with reducing the risk of edema.
They'll help keep the blood pressure stable
cuz you're putting more fluid into the intravascular space and it will regulate urine output.
Here's the examples of some hypertonic solutions.
Same ones that you saw on our summary slide.
Now, let's look at another example, D5 in half normal saline.
You'll hear us call that D5 half but it's 5% dextrose in 0.45% saline.
Now, it's one of the fluids used in DKA and we remind you there's multiple fluids that are used in DKA.
So we've got some specific parameters for you there
but just those are for your notes just for your information.
I cannot imagine you're gonna have that specific a question on an exam
but it does give you a frame of reference on where this is used.
Now, it helps us to minimize the effects of fast and drastic decrease in serum osmolality.
So we wanna avoid cerebral edema and hypoglycemia.
We're dealing with those kind of impacts that's why it's used in DKA.
Just kinda write on this slide 3 letters: D, K, A.
And for this point, that's what I remember about this solution.
One of the solutions used in DKA.
Now, we can also use it with hypotonic dehydration where the salt loss is greater than the water loss.
That may come from diuretics or impaired kidneys or decreased fluid volume
but we can use it for hypotonic dehydration.
We also use it in SIADH which is syndrome of inappropriate antidiuretic hormone
or we can use it in an Addisonian crisis.
Now, those are pretty specific applications.
Hypotonic dehydration, SIADH, or Addisonian crisis.
So those are 3 examples of when you would hang this particular solution
but you would not wanna use it with renal or CHF patients.
There's just too much of an increased risk of fluid volume overload
so you end up with heart failure and pulmonary edema.
So pay attention to where we say don't use this solution with this type of patient.
It'd be a great exercise for you to go back when you review your notes
and then make yourself a chart.
Who should not receive isotonic, hypotonic, or hypertonic solutions.
Now, here's another one that uses dextrose but it's 5% dextrose in LR.
Now, just for fun, think about it. I want you to think what you already know about LR.
You know that the liver converts lactate to bicarbonate when we talked about LR.
Now, you throw a little D5 in there.
Who would be the types of patients that you wouldn't wanna give this IV solution to?
Well, you know patients with liver disease can't metabolize lactate well.
So there you go.
There's one that you could apply that piece of information whether you're giving LR or D5LR.
You also don't want to give it to patients who are -- right, alkalotic.
That's gonna make things worse.
We do use this as a fluid for -- and as a fluid and electrolyte replenisher.
So when you hang D5LR, you should be thinking about why am I hanging this fluid,
what am I likely replacing, what lab work should I be keeping an eye on?