In this video, we will talk about metabolic acidosis. So we'll talk
about what lab values you will see with uncompensated metabolic acidosis,
partially compensated metabolic acidosis, and fully compensated metabolic acidosis. We will
also cover the causes of metabolic acidosis, what symptoms you may see in your patient,
and treatment options for metabolic acidosis. Alright. So when we look at the pH, if it is
under 7.35, then we know we have acidosis present, and we just have to figure out who's to blame.
When we look at PaCO2 here, if it's in the normal range between 35 and 45,
then we can't blame that acidosis on the respiratory system. When we go over here to HCO3,
which is bicarb which represents the metabolic system, we can see it's low, it's under 22,
which means that we have metabolic acidosis and that it is uncompensated because this respiratory
system's not doing anything to try to save the day. It's not trying to fix the situation,
it's just chilling out in its normal range, so we have uncompensated metabolic acidosis.
Then if we go to the second row here, again, if the pH is under 7.35, we have acidosis.
Who's to blame? If we look at PaCO2, it is under 35 which means it's basic. So we definitely
know that the respiratory system is not to blame for the acidosis.
However, with HCO3, we see that it is low under 22. So the metabolic system is to blame for the
acidosis. And the respiratory system is trying to fix the situation, right? It's becoming more
basic to help counteract this acidosis. So we have partially compensated metabolic
acidosis. The metabolic system is to blame for the acidosis. Respiratory system's trying to
save the day but hasn't done so completely because that pH is still out of range.
Then if we go down to this last row, if we have a pH that is within the normal range,
so it's between 7.35 and 7.45, but it's a little on the low side like if it's 7.35 or 7.36,
then you can guess there may be some compensation that is occurring.
And sure enough, if we look here at PaCO2, we'll see that it's basic. It is under 35.
And if we look at HCO3, it is acidic. It is under 22.
So we can deduce that we had metabolic acidosis that was fully compensated by
the respiratory system because our pH is in normal range.
So again the metabolic system caused the acidosis - they're to blame - and
the respiratory system came in and fixed the situation, got that pH in the normal range.
Alright. Let's talk about some of the causes of metabolic acidosis. One big cause is something
called diabetic ketoacidosis, or DKA. This is a life-threatening complication for,
typically, Type 1 diabetic patients that we see fairly regularly in the hospital.
So with DKA, these Type 1 diabetic patients, they don't produce enough insulin or any insulin,
and so the glucose can't get from the patient's bloodstream into their cells. They can't get in
there because it needs insulin to get in there. So these cells feel like they're starving to death,
right, so they start breaking down protein and fat to try to get energy. And with that breakdown
of protein and fat, we get an accumulation of acid in the body, including ketones, and
that's what causes the metabolic acidosis. Other causes of metabolic acidosis include
kidney failure, so that's another really common cause, as well as starvation, for kind of the same
reasons as DKA, right? If your cells are starving, they can't get glucose in. They start breaking
down that muscle and fat, the protein and fat, which is how we have that accumulation of acid.
Other causes include diarrhea. So one way to remember that diarrhea causes metabolic acidosis
is that you lose bicarb out the butt. Another tip that someone gave me is that with diarrhea,
you have diarrhea out the acidosis. So if either of those little tricks help you, that's great.
Other causes include dehydration, pancreatitis, liver failure, and then anything that causes
hypermetabolism. So this could be something such as a fever, seizures, or heavy exercising.
And then in terms of symptoms, symptoms of metabolic acidosis include hypotension,
tachycardia, weak pulses, GI upset such as nausea and vomiting, dysrhythmias because we often have
hyperkalemia or too high of our potassium levels when it comes to metabolic acidosis. It
happens almost all the time. So when you think of metabolic acidosis, I want you
to think of hyperkalemia. And when you think of hyperkalemia, I want you to know that there is a
high risk of life-threatening dysrhythmias when a patient's potassium levels are out of whack.
Other signs and symptoms can include Kussmaul's respirations. So you would see this with a
diabetic patient who has DKA. They have this deep rapid breathing due to respiratory compensation
for that metabolic acidosis. So just like we were talking before, the metabolic system is
to blame for the acidosis, and the respiratory system often tries to compensate. And it will
do that by increasing the depth and the rate of breathing, so you have this really deep, rapid
breathing that you see with Kussmaul respirations. Other things include a fruity odor or breath,
so that's definitely a sign of DKA and of metabolic acidosis, and then warm, flushed skin.
In terms of treatment, we can provide the patient with sodium bicarbonate. So again, we're trying to
eliminate the acid, trying to create acid-base balance. So we can give them bicarbonate.
We can also give them IV fluids as well as insulin for DKA. So by giving them insulin,
we can get that glucose into the cells so that the cells will stop trying to break down
that fat and that protein. And then, if a patient has
renal failure, like kidney failure, then hemodialysis is another option.
Okay. So that is it with metabolic acidosis. I spent a little more time
on the causes, signs and symptoms, and treatment, just because it's really important for you to know
as a nursing student and as a nurse. In my next video, we'll go over metabolic alkalosis, all
of that same information. And we're on the home stretch, so stick with me. We're almost there.