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If there is any kind of acid-base imbalance occurs, then the homeostasis mechanism of the human body tries to balance it. This can happen if the PCO_{2 } and HCO_{3 }will be in a normal range. So, at first, we will know what are the normal values of P^{H}, PCO_{2,} and HCO_{3 }ions.

P^{H }= 7.35- 7.45

PCO_{2}= 35- 45 mm/Hg

HCO_{3} =22-26 mmol/L

## compensated or uncompensated

To know about the compensation mechanism, let’s take some examples.

## case-1

## There is a patient having asthma. During ABG analysis we found that the P^{H} value, PCO_{2, }and HCO_{3} values are 7.30, 50mm/Hg, and 49mmol/L respectively. So, is it acidosis or alkalosis, and identify is it compensated or uncompensated ?

Ans. Here the P^{H }=7.30, which means acidosis. then PCO_{2} =50mm/Hg, which means respiratory acidosis. Then HCO_{3 }= 49mmol/L, which means metabolic alkalosis. But, here only the value of PCO_{2} will be considered and don’t give much importance to the value of HCO_{3. }because the body is now acidic as per the value of p^{H}. So, here the HCO_{3} was tried to balance it. but, It happened partially. not only the value of p^{H } or PCO_{2} but also the asthmatic condition of the patient shows that it is the matter of respiratory acidosis.

## case-2

## There is a patient having P^{H}, PCO_{2 }and HCO_{3 } are 7.50, 51 mm/Hg, and 41mmol/L respectively. Identify if it is compensated or uncompensated (acidosis/alkalosis)?

Ans. Here the value of P^{H }=7.50, which means alkalosis. The value of PCO_{2} = 51, which means respiratory acidosis and at last the value of HCO_{3} =41, which means metabolic alkalosis. But, here we will be considered only the value of HCO_{3} and don’t focus on the value of PCO_{2.} Because the blood is in the alkaline state as per the value of P^{H}. here also the PCO_{2} will be tried to compensate but failed. so, It is metabolic alkalosis and there is partial compensation takes place.

## case-3

## There is a man having P^{H} (7.35).But, the value of PCO_{2} and HCO_{3} are 49 mm/Hg, 30 mmol/L respectively.so, what kind of compensation it is?

Ans. The P^{H }is 7.35 which means it is normal. On the other hand the value of PCO_{2} is 49, which means respiratory acidosis, The value of HCO_{3} is 30, which means metabolic alkalosis. So, what we can do in this case, we have to divide 7.35-7.45 into two parts. like 7.35 -7.39 is considered as acidic and 7.40-7.45 is consider as basic. In this sense, the p^{H} is 7.35 which means acidosis occurs. As the blood is acidic that’s why we will only consider the pco_{2 }and ignore the value of HCO_{3.} so, It is called respiratory acidosis. but, It is fully compensated because of HCO_{3.}

## case-4

## During ABG analysis, the nurse examined that the p^{H }of the patient is 7.26, PCO_{2 }is 49mm/Hg and the value of HCO_{3} is 24. So, is it compensated or uncompensated (acidosis/alkalosis)?

Ans. The value of the patient’s P^{H} is 7.26 which means acidosis. as the value of PCO_{2} is 49, which means respiratory acidosis takes place. and the value of HCO_{3} is 24 which means metabolic acidosis. So, here we can see that there is no compensation mechanism takes place as the bicarbonate ions didn’t increase in their normal values. It is basically a respiratory acidosis case.

So, that’s all about the compensation mechanism of acid-base balance. To know about the whole concept of the acid-base balance, please read my previous blog which is about the “acid-base balance”.