Metabolic Acidosis Acid Base Balance Made Easy NCLEX Review | ABGs Made Easy for Nurses

Hey everyone, it's Sarah with RegisteredNurseRN.com and in this video, I'm going to be going over

metabolic

acidosis. In the next video, I'm going to be covering metabolic

alkalosis. So if you're studying this material, be sure to check out that video because I am doing a series on acid and base

imbalances. So in this video, what I'm going to cover is I'm going to cover a little bit of the patho behind

metabolic acidosis and break it down for what you need to know as a nursing student

and what you need to know for the NCLEX exam and your nursing lecture exams.

Then I'm going to go over the causes of metabolic acidosis and give you a clever mnemonic on how to remember those causes.

Then the signs and symptoms. How would you see a patient?

What are they going to appear to have whenever they're in this condition? And then the nursing interventions.

And then lastly, I'm going to follow it up with an arterial blood gas problem in solving for a patient who has metabolic acidosis.

And how to show you to find out if it's

compensated, partially compensated, not compensated, and things like that.

So let's get started. First, what we want to do is we want to go over the patho of this condition.

This can get really,

really in-depth. But as a nursing student who's needing to take the NCLEX or nursing exams,

I'm going to simplify it for you and tell you what you need to know specifically.

Okay, so metabolic acidosis. What is this?

Well, in the previous videos we talked about respiratory acidosis and respiratory alkalosis.

Those were respiratory issues going on in the lungs. The CO2 issues

were thrown off and it's causing the body to do all these crazy things. Here we got some metabolic

problems going on.

And we know since it's acidosis, we got acid issues. So we got metabolic problems going on with acids.

So pretty much what's happening in the body, there is too much acid built up in the body fluids

which is causing the HCO3, which is bicarb, to

decrease. It's plummeting. So remember this. Anytime you have increased acid production in the body,

your bicarb levels are going to plummet and put them into metabolic acidosis.

Now, what are some things that cause metabolic acidosis? And here in a second, we're going to go into it in depth.

But these are usually the three categories. First category,

you just have way too much acid being produced in the body. And this happens, for example, in DKA, diabetic ketoacidosis.

Hence the ketoacidosis part.

And this is what's happening is that patient's blood sugars are crazy high.

They're producing a lot of ketones. Ketones are an acid

and it's

building up in the body and it's causing the bicarb to just plummet, to go down.

Other thing, there's a decrease of acid secretion.

So what is responsible in your body for normally filtering out all those nasty waste products? Your kidneys.

So if your kidneys aren't working good, like in renal failure, they're not filtering all those byproducts, the waste out.

So you're going to keep all that acid. And whenever the acid increases, the bicarb plummets.

So the bicarb just can't regulate that imbalance of all that waste on board. So it just falls.

Next,

another third cause is loss of bicarb. You're losing it. How would you be losing it?

From diarrhea. Because diarrhea, those secretions have a lot of bicarb in them and whenever you're just

having profuse diarrhea, you're losing all that and all that acid is building up in the body.

So in turn,

what will happen is that lab values, your arterial blood gases are going to be thrown completely out of whack.

And the body is going to try to compensate. Just like in respiratory alkalosis, acidosis,

we talked about how the kidneys try to compensate for those problems going on. Now here, whenever you have

metabolic acidosis, your respiratory system tries to compensate because it's like, hey,

there is way too much acid here in the body and we got all this CO2 in our lungs, which is an acid.

So let's breathe a lot more rapidly. Let's hyperventilate

to expel this CO2 so we can hopefully

increase that blood pH back to normal and increase that

bicarb level. So that's what it's hoping to do. So you're going to see patients whenever they're in really bad metabolic acidosis,

their breathing rate is really going to be, they're going to be breathing and

the type of breathing they'll be doing is the cosmal breathing. This is

deep, rapid breaths.

And what your body is just trying to do is trying to expel all that CO2 because it's like, hey,

this is way too much acid. Let's get rid of this.

So this will throw your lab values off. So when a patient who's in metabolic acidosis,

you're going to see these falling lab values. You will see a blood pH of less than

7.35 and that is because you have all these acids on board and that

is what happens. The pH drops and a normal blood pH is 7.35 to 7.45.

So anything less than 7.35 is an acid.

Your HCO3, which is your bicarb, will be less than 22 because remember it just plummets whenever you get all these

acidotic conditions. And a normal bicarb level is 22 to 26.

And your PaCO2, which is your carbon dioxide level, is also

going to

decrease or it could stay normal. If it's not, the body's not compensating yet,

it'll be normal between 35 to 45.

But if it is trying to compensate, it will drop because remember it's trying to expel all that CO2.

So it'll be less than 35.

So now let's look at the causes of metabolic acidosis. Okay.

Before we get into the mnemonic,

let me lay the framework because in order to treat as the doctor who is going to be treating it,

we need to look back at this so we'll know

why the doctor is ordering these certain orders, how they know it's this type of metabolic acidosis.

So let's just lay the framework for this and then we'll go into the exact causes.

Okay, there are two different types of causes of metabolic acidosis. You have a high anion gap

or a normal anion gap.

And the reason that it's so important to know if the patient is in a high anion gap or a normal anion gap

is so the doctor can treat the cause because if they don't figure out exactly what's causing it, like for instance diabetic ketoacidosis,

which is a high anion gap and they don't treat that correctly,

this is life-threatening and the patient can die. So they have to pinpoint the cause in order to order the proper treatments.

So what in the world is an anion gap?

Simplified for what we need to know as nurses,

this is where the doctor looks at various lab values in the patient's blood work, for instance electrolytes like chloride, bicarbonate, and sodium,

and they calculate this to see the difference between the anions and the cations. And they're looking for this gap.

And if there is a gap in between this calculation from the normal greater than 14

milliequivalents per liter from the normal, which a normal anion gap is 10 to 14 milliequivalents per liter,

this means that it's a high anion gap cause. So they calculate it. They get a value greater than 14 milliequivalents per liter.

It's a high anion gap.

So

high anion gap acidosis, what conditions cause it? We'll go over that here in a second.

But typically what causes it is where the body starts to produce too much acid and not enough bicarb.

So,

for instance, diabetic ketoacidosis. There's too much acid in the body and the bicarb's dropping.

So that's a high anion acidosis. What are causes of the normal anion gap?

Acidosis. These are any conditions that cause your body to just lose that bicarb like in diarrhea. Okay, so

how do you remember all that? I wanted to take the high anion gap and the normal anion gap and just

put them together to help you remember it as a nursing student.

So what we're going to do is we're going to remember the mnemonic acidotic. We're in acidotic conditions.

So that's easy to remember and each letter will correlate with the cause. So let's get started.

Okay, A for aspirin toxicity.

This is a high anion gap because what's happening is whenever a patient

either accidentally or

on purpose like in the suicide attempt takes a whole bottle of aspirin in the body, all that aspirin is going to enter into the

gut and the body's going to absorb it and it is just going to increase all of the acid in the body.

And whenever that happens, you start getting hyperventilation and you also get respiratory

alkalosis, which we talked about that in the respiratory alkalosis. That was one of our causes.

So aspirin toxicity, taking all that aspirin is going to increase

the acid in your blood. Okay, C for carbohydrates not metabolized. There are conditions where patients

people have issues metabolizing carbohydrates and whenever this happens,

there's not enough oxygen to break down

those pyruvic acids. And pyruvic acids, what they are, they supply energy to the cell,

but the oxygen is not allowing us to break those acids down. So whenever those acids don't break down,

they start to turn into

lactic acid and whenever you have buildup of lactic acid that throws the body off

and that's going to cause your bicarb levels to plummet.

Okay, I for insufficiency of the kidneys and this is a high anion gap

metabolic acidosis, just like the carbohydrates was as well.

I didn't say that in the other one, but carbohydrate not metabolizing carbohydrates is high anion gap metabolic acidosis.

But with the insufficiency of the kidneys, like I talked about the beginning of the video, the kidneys aren't filtering out the waste in the blood.

So this increases acids. Remember when acids increase in the body, your bicarb falls.

Okay, D for diarrhea.

Okay,

your GI fluids and your pancreatic fluids, all those fluids are rich in bicarb, HCO3,

alkalotic fluids. And whenever you're losing a lot of that,

you're going to increase the acid because you've got rid of all the alkaline fluids. So what's left over is the acid.

So that again is going to make your bicarb drop. And then the other D, just help you remember,

the other D is a DKA, diabetic ketoacidosis. Remember you have too many ketones on board which are an acid

and it's all over the body. Body can't compensate. So what happens is that the bicarb levels fall.

Okay, O

for ostomy drainage. And this is a normal anion gap one,

just like the diarrhea is a normal anion gap. Because again, that's where the body is losing too much bicarb.

So with the ostomy drainage, you need to pay attention to especially

ileostomies.

Because these fluids are rich in bicarb. And normally

whenever stuff travels through your body, out through your stool,

the stool is low in bicarb because the body's absorbed it, regulated it.

But whenever you have an ileostomy or other ostomies, you're stopping at a certain point.

So if you're having excessive drainage come out, all that fluid is really rich in bicarb.

And it's not going to pass normally through the gut like it's supposed to.

So you have to really watch these patients who do have ileostomies

for

metabolic acidosis because they're going to lose a lot of bicarb through there. So you have to watch that.

Okay, T for fistula. We'll use the T in fistula. And this is like the same concept as ostomy.

Fistulas are where you have a hollow passage either between an organ and the body surface or between two organs

where fluids are going through.

And normally that's not supposed to happen because those fluids are supposed to stay and go and be transported throughout the body where they're

supposed to go. So they are again, just like the ostomy drainage, rich in

bicarb. They're alkalotic. So if you're losing them somewhere, you're not needing to lose them.

You're definitely at risk for developing metabolic acidosis because you're losing all that alkaline fluid which increases the acids.

Okay, and

I for intake of a high fat diet.

This is a high aniline gap. And this is where if you are consuming way too much fat in your diet,

you're not having a good balanced diet. You're just eating a lot of fat.

What happens is that you're going to have increased waste and acids and ketones in your body.

And your body's not going to be able to compensate for all this fat acids, all that nasty stuff on board.

And it's going to cause the bicarb to decrease. Okay, and last

C for carbonic anhydrase inhibitors. These drugs,

and remember this, this is a big one. For instance,

Diamox. Diamox is a diuretic. We will be talking about this in metabolic alkalosis.

It's actually a treatment for metabolic alkalosis. So remember this drug, Diamox. It's a carbonic anhydrase inhibitor.

And this, what happens is this is a diuretic and it

causes to decrease the reabsorption of bicarb. So the patient's urinating and

to urinate, it's causing you to not reabsorb that bicarb.

So if a patient's been taking way too much Diamox or their body hasn't been responding appropriately to it,

they're definitely at risk for metabolic

acidosis. So now let's talk about how your patient's going to look, the nursing interventions, and then let's work an ABG problem.

So how are these patients going to look to you as the nurse? What are they going to have signs and symptoms wise?

Okay, the first thing that you just want to remember out of this whole signs and symptoms area is the causal breathing.

This, remember, was the body's attempt in the respiratory system to try to compensate for those acidic conditions

by blowing off that CO2, which is an acid. So they're going to have

deep and rapid breathing, greater than 20 breaths per minute, up into the 40.

So that is a big sign, especially in diabetic ketoacidosis.

They may also be weak, confused, have a low blood pressure,

and they could have cardiac changes. And this is due to the increased potassium hyperkalemia.

We talked about this in the hyperkalemia video. So be sure to check out that video as well.

And nausea and vomiting. So what are you going to do for this patient as the nurse?

Well, it totally depends on what is causing this. Is it diabetic ketoacidosis? Is it diarrhea?

Is it renal failure? So depending on what's causing it will vary your treatment.

But what you need to do with all of these conditions is watch for respiratory distress.

And this is coming from your causal breathing. If that patient blows off so much CO2 and drops those levels less than 35,

they can be in really big trouble. So they may need some intubation, mechanical ventilation.

Watch those other electrolyte levels, especially the high potassium levels.

Because whenever metabolic acidosis is actively going on, they're going to have high potassium levels.

But whenever you're starting to correct it,

you have to watch out because you can flip them into hypokalemia.

Because what's happening is that potassium is going to go back into that cell.

So all that potassium was in the blood and hyperkalemia is going to shift intracellularly

and cause hypokalemia.

There's not going to be any potassium left in the blood because you're trying to correct the state.

So you need to watch out for that as well. And other neurostatus and seizures may put them in seizure precautions.

Okay. Now I just wanted to discuss if the patient was in renal failure.

One thing you need to do is you need to get strict

I's and O's, intake, output, things like that. Be watching their urinary output. Be watching their other lab values.

Because whenever a patient's in renal failure, they can have high potassium,

high BUN creatinine. You really got to watch those levels and watch their diet, what they're eating,

how much fluids they're drinking. And also the patient may be a candidate for dialysis to go in to remove that

extra waste acids off the body and help correct this.

Now if they are in DKA, diabetic ketoacidosis,

typically what will happen is that the doctor will order you to start them on like an insulin drip maybe

where you'll be titrating insulin, giving them, watching their blood sugars very very closely.

And what's going to happen is that that insulin is going to act as a little

transporter and help take that glucose back into the cell, which will help the body to start metabolizing the glucose correctly.

Instead of metabolizing those ketones, which it was breaking down ketones.

When you break down the ketones, it goes in the body, increases the acid, which throws them in metabolic acidosis. So

you may be doing that if the patient's in that.

Okay, so now let's work an arterial blood gas problem that you may encounter on the NCLEX or in nursing school.

And I want to go in depth about

if it's compensated, not compensated, what would look like if it was fully compensated.

And I use the tic-tac-toe method when solving ABGs.

It's one of the best ways for us nurses to get a quick result of what we need, super easy.

And I have a video on how to solve the tic-tac-toe method. A card should be popping up or a link in the description below.

And I go into depth. I've had to set these problems up.

So I'd watch that video if you're not familiar with this, how to do this.

Okay, so what you want to do very first thing is look at your

blood gas values. Okay, we have a bicarb HCO3 of 11. We have a pH of 7.2

and we have a PaCO2 of 42. So let's plug them in our tic-tac-toe and see what we get.

Okay, our bicarb HCO3 is 11. We know that a normal bicarb is 22 to 26.

So this is acidic.

So HCO3 will go under acid.

And pH is 7.2. We know that a normal pH is 7.35 to 7.45. So this is

acidic as well. And we have a tic-tac-toe.

And

whenever you have a tic-tac-toe, you look and see what's under it. We have metabolic because HCO3 represents

metabolic and our pH is acidic. So we have metabolic acidosis.

Now, let's see if it's compensated or not compensated or fully compensated. To do that, remember what happens when you're metabolic

acidosis or metabolic problems. Your lungs start to try to compensate. And in this condition,

it's going to try to start blowing off the CO2.

So we're going to say to ourself, well, if the body was compensating, the CO2

must be low because it's trying to blow it off if it was compensated. So what's our CO2?

Our CO2 is

42. A normal CO2 level is 35 to 45. So it's normal. It's not really doing anything.

So we're going to put it here.

So we know the answer to this is metabolic acidosis not compensated.

Now say that the

CO2 we'll say was 33.

Okay, if it was 33,

it means that our levels dropped because it's less than 35. So the body has been trying to compensate. So we'll put it under the base

one and it would be

metabolic acidosis

partially compensated. Now, why is it partially compensated?

The reason it's partially compensated is because our pH is still abnormal. If

the respiratory system had corrected it, our pH would have went back up into the 7.3 to 7.4

range. So the body has helped correct itself, which would hopefully bring the bicarb back up too as well.

So this is not fully compensated because the pH is still abnormal.

Okay, so that is how and that's a little bit about metabolic acidosis.

Please check out the video on metabolic alkalosis and don't forget to take the free quiz on my website

registerednursern.com. A card should be popping up or a link in the description below to test your knowledge on metabolic alkalosis and metabolic

acidosis. Thank you so much for watching and please consider subscribing to this YouTube channel.