ABG Interpretation Help

  1. Help! I have a 60 year old female patient who was admitted with dehydration, renal failure, and hyperkalemia. Her ABGs is as follows.
    PH 7.315 L
    pCO2 81.5 H
    pO2 49.7 L
    HCO3 35.8 H
    Base Excess 13.7 H
    Is this due to her renal failure or is this metabolic alkalosis? Any ideas?
    •  
  2. 6 Comments

  3. by   cardiacRN2006
    Quote from 1RNStudent
    Help! I have a 60 year old female patient who was admitted with dehydration, renal failure, and hyperkalemia. Her ABGs is as follows.
    PH 7.315 L
    pCO2 81.5 H
    pO2 49.7 L
    HCO3 35.8 H
    Base Excess 13.7 H
    Is this due to her renal failure or is this metabolic alkalosis? Any ideas?

    It's not alkalosis at all. It's acidosis.

    Lot of ideas come to mind with these crappy ABG values!

    Was this person on O2?
    What was RR?
    What was the K?
    What does this patient LOOK like? In distress?

    Or...
    How would you treat a PO2 of 49? What about that CO2?

    These numbers are awful!
  4. by   1RNStudent
    I didn't actually get to see the patient. This was an assignment where I pre-planned with my "big sister" (2nd year RN student) I was just to interpret her lab values and do a med. sheet. Her K was 6.6 H on admission but had dropped to 3.9 by yesterday afternoon. I don't think the patient was in acute distress by the way the nurses at the station were talking. Her CO2 in her electrolyte panel was 36 H, her Na was 141, her Cl was 97 L, her Creat was 0.3 L, her Mg was 1.4 L and her Ca was 8.6 L. Her Calc. Osmolality was 297 H. Talk about sucky labs! Any further suggestions?
  5. by   SarasotaRN2b
    Quote from 1RNStudent
    Help! I have a 60 year old female patient who was admitted with dehydration, renal failure, and hyperkalemia. Her ABGs is as follows.
    PH 7.315 L
    pCO2 81.5 H
    pO2 49.7 L
    HCO3 35.8 H
    Base Excess 13.7 H
    Is this due to her renal failure or is this metabolic alkalosis? Any ideas?
    If you do a search for ABG's you'll find a great some great resources.

    For starters though, because her pH is <7.35, it is acidosis (>7.45 would be alkalosis), right away you will rule out metabolic alkalosis. With a PCO2 of 81.5 which is > the normal of 35-45, there is respiratory acidosis.

    There is definitely something metabolic going on wit h that high of a HCO3.

    Kris
  6. by   1RNStudent
    I wonder if her renal failure would cause the metabolic issues. It just seems that her kidneys are not excreting wastes as they should. Wouldn't this account for all the abnormal highs?
  7. by   Daytonite
    this is respiratory acidosis where the ph is diminished and the pco2 is elevated. you can use the rome mnemonic to determine this (post #25 of http://allnurses.com/forums/f205/pat...es-145201.html). the hco3 is high because the patient's body is compensating by retaining hco3 in order to increase the body's ph.

    in looking at the patient lab results that you posted, they were all normal except for:
    • her co2 in her electrolyte panel was 36 - slightly elevated, but not critical - this is often seen in gi conditions where the patient has been losing gi fluids through vomiting or diarrhea
    • creat was 0.3 (low) - seen in debilitating conditions [i.e. chronic renal failure] where the patient is not very mobile, decreased muscle mass
    • calc. osmolality was 297 - slightly elevated, but not critical - this is seen in dehydration and uremia
    did the patient's dramatic potassium level drop because she had a dialysis treatment? chronic renal patients will come in with really skewed electrolytes before dialysis because their kidneys are so damaged that they can't correct the imbalances. hemodialysis, however, corrects many of the imbalances until the next treatment. i think correlation with the patient's physical condition will answer many of the questions that you have about some of this labwork.

    there are all kinds of abg's weblinks on post #46 of this sticky thread:
  8. by   Nrs_angie
    Quote from 1RNStudent
    Help! I have a 60 year old female patient who was admitted with dehydration, renal failure, and hyperkalemia. Her ABGs is as follows.
    PH 7.315 L
    pCO2 81.5 H
    pO2 49.7 L
    HCO3 35.8 H
    Base Excess 13.7 H
    Is this due to her renal failure or is this metabolic alkalosis? Any ideas?
    Looking like you need a quick lesson in ABG interrpretation.

    1: look at the PH... its low so thats ACIDOTIC
    2: look at the CO2... its veryyyy high so that is also ACIDOTIC
    3: look at the Bicarb (HCO3)... its also pretty darn high, which is Alkalotic.

    Because the PH is acid, the problem here is going to be ACIDOSIS.
    Because the CO2 is also ACIDOTIC, that tells you that it is RESPIRATORY in nature.
    Hence, the acid-base disturbance is RESPIRATORY ACIDOSIS.

    4: look for other abnormal values... the Bicarb is high, so it is attempting to compensate by making the blood more alkalotic and less acidotic.

    5: look at the pO2... its very low and this number I believe falls into the moderate to severe hypoxemia.

    Hence, your final ABG interrpretation is: RESPIRATORY ACIDOSIS WITH MODERATE TO SEVERE HYPOXEMIA.

    Causes for Respiratory Acidosis are COPD, NEUROmuscular disorders such as ALS or Guillain-Barr syndrome, Obesity, Narcotics such as Morphine, or CNS depressants such as Benzos, or anything that would cause hypoventilation.

    You didn't mention any of these in your assessment, so I can not assume here why this patient has Resp. Acidosis.

    The hyperkalemia goes hand and in hand with the Renal failure, as Daytonite already mentioned. I also agree with her interpretation of the other labs.

    Good luck,, hope this helps some,
    Angie

close