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another acid-base question for clarification:

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by GingerSue GingerSue (Member)

GingerSue has 20 years experience .

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in this eg. the

pH is 7.20

PCO2 is 78

HCO3 is 30

this is respiratory acidosis

the client is compensating, and is partiallly compensated.

the explanation that is provided for this specific question re: compensating is "the pH and HCO3 are changing in the same direction"

I can see that the pH is decreased. But the HCO3 is elevated. So, can anyone explain how it is seen that the pH and HCO3 are changing in the same direction? Why does it seem to me that they are in opposite directions. It seems to me that the PCO2 and the HCO3 are moving in the same direction (both increasing).

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Myxel67 has 15 years experience and specializes in Diabetes ED, (CDE), CCU, Pulmonary/HIV.

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I think it means that the pH is on its way up, as is the HCO3.

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GingerSue has 20 years experience.

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why would I think that the pH is on its way up?

in the chart that is provided, when the pH is below 7.4 it is called decreased.

and the earlier explanation of the pH and PCO2 is that they are changing in opposite directions.

Therefore, why would I think of the pH as decreased in relation to the PCO2, but increasing in relation to the HCO3?

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The pH is acidic.

The CO2 is significantly elevated, indicating a respiratory acidosis.

The HCO3 is slightly elevated, indicating minimal metabolic compensation.

When you analyze blood gasses, look at each component individually. I think you are causing yourself needless confusion by trying to "match up" different components. You can't memorize blood gasses, you need to be able to analyze them. It just takes practice.

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GingerSue has 20 years experience.

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not attempting to memorize anything

trying to understand the explanations provided

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GingerSue has 20 years experience.

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it is "compensation" that I am trying to clarify

(not acidosis nor alkalosis)

compensation is about the ratio of carbonic acid to base bicarbonate and

the ratio is 1:20 and this is then to restore the balance and then pH will return to its normal range

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In determining compensation, I am simply looking at the HCO3 value. Norm is 22-26. The value in this instance is 30, which is only slightly elevated. So the patient's body is TRYING to compensate for the respiratory acidosis by retaining metabolic acids, but is not doing a very good job of it, certainly not enough to bring the pH back to a normal range.

In reality, the management of this patient would probably involve ventilation to "blow off" the excess CO2. It is not likely that the patient's body is capable of balancing out the pH on its own.

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Ann RN specializes in ICU/CCU, CVICU, Trauma.

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in this eg. the

pH is 7.20

PCO2 is 78

HCO3 is 30

this is respiratory acidosis

the client is compensating, and is partiallly compensated.

the explanation that is provided for this specific question re: compensating is "the pH and HCO3 are changing in the same direction"

I can see that the pH is decreased. But the HCO3 is elevated. So, can anyone explain how it is seen that the pH and HCO3 are changing in the same direction? Why does it seem to me that they are in opposite directions. It seems to me that the PCO2 and the HCO3 are moving in the same direction (both increasing).

Some may argue with me, but this is not a compensated blood gas. It is only compensated if the pH is "normal".

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36 Posts; 1,585 Profile Views

respiratory acidosis

ph paco2 hco3

uncompensated down up normal

partial comp down up up

fully comp normal up up

respiratory alkalosis

ph paco2 hco3

uncompensated up down normal

partial comp up down down

fully comp normal down down

so 7.20 down

78 up

30 up

partial compensated

hope this helps

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36 Posts; 1,585 Profile Views

To answer the second part of your question.... When Ph decrease we have a acidic environment, the body want to compensate by add base or bicarb to bring the acid back up to the normal range.. This why you are seeing an increase in bicarb during partial or fully compensated acidosis. Hope this is heplful

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cardiacRN2006 is a ADN, RN and specializes in Cardiac.

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Some may argue with me, but this is not a compensated blood gas. It is only compensated if the pH is "normal".

The OP said it was partially compensated, which it is...

why would I think that the pH is on its way up?

Because if the Bicarb wasn't elevated, then the pH would be even lower...

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