It took me a while to understand Acid-Base Imbalances. I still don't understand how to figure out about compensation. Please help... after step 3, it' s all blurry.
Step 1:
Evaluate pH
pH
pH >7.45 - Alkalosis
Step 2:
Evaluate pCO2
>45 pCO2 - Respiratory Acidosis
Step3:
Evaluate HCO3
>26 - HCO3 - Metabolic Alkalosis
Step 4:
?
How do you determine compensation? If pH is within normal limits - compensation has occur but what happens if it's not?
I would like to ask you, if pH is only one measurement to show compensation?
I'm not DocsWifey, but no, pH isn't the only measurement you look at when trying to figure out compensation. You also have to take into account the HCO3- and pCO2 levels, along with the rest of the clinical picture (including anion gap, etc). There are also additional calculations we generally use in the clinic with acid/base disturbances (ex. Winter's formula, etc). These help in evaluating compensation mechanisms.
I personally prefer to stick with basic chemistry principles when working with acid/base disturbances rather than working with various formulas, etc. It makes more intuitive sense, in my opinion. Take a look at the following article to get a more thorough understanding of this stuff. It's a very, very quick read and pretty easy to understand:
Understand the concept of the carbonic anhydrase mechanism and Le Chatelier's Principle, as I mentioned in my previous post, and it'll make the reading much more simpler and intuitive. Seriously, when learning this stuff, it's better not to get bogged down on details or formulas or whatever. Understand the concept and add more layers of complexity afterwards.
I had the same problem and never understood acid-base balance. Now I'm just going with the basic principle. If the pH is normal, the patient is compensated, if it's abnormal the patient is either uncompensated or on his way to compensation.
studentdrtobe is right, there is more than the ph to figure out compensation but if you have see ABG's only stick with the pH to see in what kind of acid base imbalance your patient is.
Always look at the clinical picture too though, if the patient is in DKA for example but you figured out he is in alkalosis something is obviously off.
Don't get too much into detail right now, try to understand the basics first - know how what kind of acid base imbalance your patient has with the pH, CO2, and HCO3
If you are a foreign nurse trying to pass NCLEX_RN exam... Saunders is great but incomplete in some parts. Thank you guys for all your support and patience with a Nursing Dummy! I set a side my Nursing career until children will be old enough but now I feel like I need to study Chemistry with them all over again. :thankya: Thank you all!
All I remember answering acid base balance is ROME®espiratory (o)pposite(M)etabolic (e)qualSo I write down the ph, pco2, and hco3. To know is it's acidic or alkaline. I look at the ph level.
ph 7.45 arrow is going up alkali ticSame with co2 and hco3 Then plot your arrow.
Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
from an article written by vicki assist.admin....theses are great!https://allnurses.com/nursing-student-assistance/active-learning-strategy-387179.html
If both HC03 and PC02 are abnormal then the body is compensating so then you look at pH again. If the pH is within normal limits then it is Fully compensating if it is not within normal limits then it is partially compensating:-)
studentdrtobe
63 Posts
I'm not DocsWifey, but no, pH isn't the only measurement you look at when trying to figure out compensation. You also have to take into account the HCO3- and pCO2 levels, along with the rest of the clinical picture (including anion gap, etc). There are also additional calculations we generally use in the clinic with acid/base disturbances (ex. Winter's formula, etc). These help in evaluating compensation mechanisms.
I personally prefer to stick with basic chemistry principles when working with acid/base disturbances rather than working with various formulas, etc. It makes more intuitive sense, in my opinion. Take a look at the following article to get a more thorough understanding of this stuff. It's a very, very quick read and pretty easy to understand:
A practical approach to acid-base disorders. [West J Med. 1991] - PubMed - NCBI
Understand the concept of the carbonic anhydrase mechanism and Le Chatelier's Principle, as I mentioned in my previous post, and it'll make the reading much more simpler and intuitive. Seriously, when learning this stuff, it's better not to get bogged down on details or formulas or whatever. Understand the concept and add more layers of complexity afterwards.
Hope this helps.