Posting this here because it’s been a constant frustration to me in understanding it. I’ve tried reading multiple sources / listening to videos explain it and something is just not clicking.
Essentially, how does the acid/base balance work in our body in regards to how our lungs and kidneys react? I know I can memorize acidosis / alkalosis through the ROME method or the Tic Tac Toe method, but I want to finally understand the mechanics of it all.
Bonus: To get into the issue deeper, how do I know if the body is fully or partially compensated?
In: Biology
Hey,
I am a respiratory therapist and this concept is our bread and butter.
First off let’s discuss what organs contribute to this process. The lungs remove CO2, which is an acidic compound, from the blood via ventilation. The normal range of CO2 is 35-45mmHg. The kidneys produce/remove HCO3, which is an alkaline compound. Normal range of HCO3 is 22-26mmHG. The normal pH range of blood is 7.35-7.45.
If there is an abundance of HCO3, the body will correct this by increasing ventilation (removing more CO2). If the HCO3 is below normal, the body will decrease ventilation (retaining more CO2). This works since acids and bases cancel each other out.
If the body isn’t ventilating very well (retaining too much CO2) the kidneys will eventually start to produce more HCO3. The kidneys take a day or two to recognize and react to a problem. Too little CO2 the kidneys will start to remove more HCO3.
To understand compensation you have to look at the entire blood gas. Partial compensation is when the body is trying to correct the problem, but the pH is still abnormal. Full compensation is when abnormal values result in a normal pH value. I will give an abnormal gas as an example and show how a partial compensation and full compensation would look like.
Start off with a respiratory acidosis blood gas of : 7.30, CO2: 75, HCO3: 24. A partially compensated respiratory acidosis would look like this : 7.33, CO2: 75, HCO3: 27. This is partial due to the pH still being low. You can tell that is is compensating though due to the rise is HCO3. A full compensation would look like : 7.35, CO2: 75, HCO3: 30. This is full compensation because the pH is now normalized.
Hope this helps!
Kidneys regulate base (bicarbonate) and respond slowly.
Lungs control acid (CO2) and respond quickly.
“Compensated” just means that one of those systems is responding well enough to correct the imbalance that the pH is in the normal range (7.35-7.45).
Looks like you got some sufficient answers already, but Medcram can help if you haven’t seen this series yet. The compensation piece just means even with a problem, the pH remains inside a normal range due to workload in either bicarbonate or CO2.
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