Okay. In this video, we are going to talk about respiratory acidosis.
We're going to talk about what values you will see for uncompensated respiratory acidosis,
partially compensated respiratory acidosis, and fully compensated respiratory acidosis.
We will then talk about some causes of respiratory acidosis, what symptoms you can expect to see in
your patient with this type of imbalance and how we can treat respiratory acidosis.
Okay. So when we look at the pH, and if the pH is under 7.35, that means we have acidosis.
Remember that's the first step of our process. So now we're going to figure out who's to blame.
Well, when we look at PaCO2, if that is over 45, that is indicative of respiratory acidosis,
so we know that the respiratory system is to blame. We have respiratory acidosis.
The next thing we need to check is for compensation. So when we look at HCO3,
if it is within normal range, that means that the metabolic system is not trying to
compensate for this respiratory acidosis. So if we have values that fall within these ranges,
we have uncompensated respiratory acidosis. The respiratory system is to blame for the
acidosis, and the metabolic system is not currently trying to fix the situation.
Let's look at this next row down. Again, pH is under 7.35, so we have acidosis.
Our PaCO2 is over 45. So we have respiratory acidosis. Now let's look at bicarb. If the
bicarb level, HCO3, is over 26, that is basic, which means that the metabolic system is trying
to compensate for this respiratory acidosis. But because the pH is still under 7.35, it hasn't done
the job completely. So in this case, we have partially-compensated respiratory acidosis,
which means that the respiratory system is to blame for the acidosis. The metabolic system is
trying to fix the situation, right, by becoming more basic. But it hasn't completely fixed the
situation because our pH is still out of range. Let's look at the third row down.
If the pH is within the normal range, but is a little bit on the acidic side-- so if the pH,
for example, is 7.35 exactly, or 7.36, well those numbers are within the normal ranges,
but they're a little on the acidic side. So if our pH is normal, but on the acidic
side, and we look here and the PaCO2 levels are over 45, we can guess that we have respiratory
acidosis that is likely being compensated. And sure enough, when we look over here at HCO3,
it is over 26, which is basic. So in this situation, we have a normal pH but a little
on the acidic side, we have the respiratory system that is causing the respiratory acidosis,
and we have the metabolic system, which is coming in to save the day by becoming more
basic and balancing out that pH. So we have fully compensated respiratory acidosis in this case.
The key cause for respiratory acidosis is really hypoventilation, and this hypoventilation
can be due to a number of pulmonary or respiratory conditions, including acute respiratory distress
syndrome, asthma, COPD, pneumonia, a pneumothorax, a pulmonary embolism. If the patient has had some
kind of chest trauma and they can't expand their chest to take in a nice, deep breath,
that can result in respiratory acidosis. Also, if a patient has had too many opioid analgesics, that
definitely results in respiratory depression, as will taking too many benzodiazepines for anxiety.
So in terms of symptoms, some of the symptoms you may see with respiratory
acidosis include confusion, lethargy, difficulty breathing, which is dyspnea.
The patient may also have pale or cyanotic skin. And then, with prolonged respiratory acidosis,
the patient may have something called polycythemia, which means that they have
a lot of red blood cells in their blood. So the percentage of red blood cells there is quite high,
which results in a high hematocrit level. In addition, with prolonged respiratory acidosis,
the patient may end up with pulmonary hypertension or heart failure as well.
In terms of treatment, we can provide the patient with oxygen. We can also give them bronchodilators
for obstructive airway diseases, such as COPD or asthma. So we can give them a bronchodilator
to help expand that airway. We can also give naloxone
for an opioid overdose and we can give flumazenil for a benzodiazepine overdose.
And then, lastly, for really serious conditions, we can do mechanical ventilation as well.
Okay, so that's it for respiratory acidosis. In my next video, we will
cover respiratory alkalosis and go over all of this same information for that condition.