If given 3 blood gases what's the best way to tell if their state is (respiratory metabolic acidosis, etc)

Question

Need some ways to remember this stuff quickly!

Answer 1

1. look at ph (over 7.4 is alkalosis, under 7.4 is acidosis)
2. look at pCO2 (partial pressure of dissolved carbond dioxide)-this will tell you the respiratory aspect
3. Look at HCO3, this tells you the metabolic aspect
4. Now combine every thing and determine if you have a metabolic acidosis, metabolic alkalosis, respiratory acidosis or respiratory alkalosis
5. check for physiologic compensation .

NOTES: do not confuse TCO2 (serum bicarb) with pCO2 (partial pressure of carbon dioxide)

Metabolic acidosis-decrease in HCO3, decrease ph (if there is compensation will increase respiration to decrease pCO2-get rid of co2 becase makes blood acidic)

Metabolic alkalosis-increase HCO3, increase Ph (compensation will include decreased respiration and increased pCO2)

Respriatory acidosis-increased pCO2, decreased Ph (compensation includes renal retention of HCO3-because this is a base and you want to reverse acididity)

Respiratory alkalosis-decreased pCO2, increased ph (compesnation is renal excretion of HCO3)

Answer 2

First- look at the pH. Is it acidotic or alkalotic?
That determines acidosis or alkolosis.
Second- Once you have determined the above, you know that for instance in acidosis the CO2 would have to be high or the bicarbonate level would need to be low. If it is a high CO2 then the problem is respiratory. If the CO2 is normal or low (compensation) then the bicarbonate must be low. This would be reversed in alkalosis. You do not need 3 blood gases to determine this.
If the Ph is with in normal range but the bicarb or CO2 level are off then the body has compensated to bring the pH to normal but you still have an issue.