[bt92019]

HI,
I'm reading ch#10(acid-base balance) from saunder's & I've a que. about compensation mechanism. I answered the que.#4 based on compensation rules on pg#107(saunder's 3rd edition-color print) & I got wrong when i read rationales it's saying opposite rules than what they are saynig in pg#107. can someone pl. explain it to me about compensation mechanism.

>HOW CAN U FIGURE IT OUT IN RESP.ACIDOSIS & RESP. ALKALOSIS -PARTIAL COMPENSATION & UNCOMPENSATION.

>SAME THING ABOUT METABOLIC ACIDOSIS & MET. ALKALOSI - PARTIAL COMPENSATION & UNCOMPENSATION

I know one thing is that when compensation occurs ph stays within normal limits. only problem with pco2 & hco3 compensation & uncompensation. I'll greatly appreciate your help.

Thanks.

[EricEnfermero]

You're right that full compensation will give you a normal pH. So if you're seeing a pH outside the normal range, your disorder is either uncompensated or partially compensated. You determine which one by looking at the 'odd man out' - the value that is not part of your initial diagnosis.

For example, if your pH is low and your CO2 is high, you have a respiratory acidosis. (Respiratory - pH and CO2 are opposite.) So for compensation, we look at bicarb. In partial compensation, the bicarb (the base) would be high in an attempt to neutralize the acidosis. Otherwise, no compensation.

In respiratory alkalosis, you know your pH is high and your CO2 is low. In partial compensation, your bicarb (base) would be low, compensating for the fact that your pH is already too alkalotic.

For metabolic acidosis, your pH will be low and your bicarb low as well. In partial compensation, you'll see the CO2 (acid) decrease so that the blood doesn't become any more acidic.

In metabolic alkalosis, your pH is high and your bicarb is high. In partial compensation, the CO2 (acid) would be high as well, in an attempt to make the pH come down.