Explanation of Compensated, Partially Compensated, and Uncompensated ABG PDF

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Explanation of Compensated, Partially Compensated, and Uncompensated ABG Compensated: This means the body was able to bring the pH back into the normal range So - the pH has to be normal for it to be compensated! (The pH can also be normal if it is a normal blood gas - but if either the CO2 or the HCO3 are abnormal, then it's compensated not normal) Once you figure out it's compensated, then you have to figure out what it was before it was compensated - was it an acidosis or alkalosis before the body was able to bring the pH back to normal. To figure this out, look at which end of the normal range the pH is at - and that will tell you what it was. Example: pH -7.35 CO2-51 HCO3-28 Look at the pH - it is normal, look at CO2 - it is abnormal, so you know this is compensated and not a normal blood gas. Go back and see which end of the normal range the pH is - it's at the low end, which is the acidic end - so this was an acidosis. Now look at the CO2 and HCO3 to determine whether it was a respiratory or metabolic acidosis...CO2 is elevated and so is HCO3 - too much acid (CO2) would give you an acidosis - so it was a respiratory acidosis Interpretation: compensated respiratory acidosis Partially compensated: This means the body is trying the fix the pH problem, but has not been able to bring the pH back into the normal range yet. So all 3 of your values (pH, CO2, HCO3) are going to be abnormal...but the CO2 and HCO3 will be going in the same direction (they'll either be both high or low). Example: pH-7.49 CO2-49 HCO3-28 The pH is high - so you know this is an alkalosis. The CO2 is high...too much acid does not cause an alkalosis, so you know the CO2 is not the cause - it's trying to fix the alkalosis. The HCO3 is high, so too much base can cause the alkalosis. Interpretation: partially compensated metabolic alkalosis Uncompensated: This means either both the CO2 and HCO3 are causing the problem (both will be abnormal, but going in different directions - one will be high and the other low) - this would be an uncompensated mixed problem OR the body has not responded yet to the imbalance, which means either the CO2 or HCO3 value will be normal. Example: pH-7.33 CO2-48 HCO3-25 The pH shows an acidosis, the CO2 is high, high acid can cause an acidosis - so this is respiratory acidosis, the HCO3 is normal because it is not trying to fix the problem yet Interpretation: uncompensated respiratory acidosis Example: pH-7.33 CO2-48 HCO3-20 As above, pH shows acidosis, CO2 is high causing acidosis, but now the HCO3 is also low - too little base can cause acidosis - so both the CO2 and the HCO3 are causing the problem Interpretation: uncompensated mixed acidosis (mixed blood gases are always uncompensated)

LLS 3-1-2019...