please help with these ABG's - page 2

82yo male on bipap FIO2 90% with diagnosis of pneumonia. o2 sats WNL. ph 7.54 pco2 51 p02 64 hco3 43.6 BE 18.5 I am a relatively new ICU nurse and ABG's aren't my strong point. Charge RN... Read More

  1. by   texasnursingstudent
    ph 7.54 ALK
    pco2 51 ACID
    p02 64 indicates that the body does not have enough oxygen in the blood or "hypoxemia."
    hco3 43.6 ALK
    BE 18.5 pretty high base excess there

    partially compensated
    the bicarb is high, as in alkalotic. the pH is also high, that is, it is also alkalotic. this means that we have metabolic alkalosis. to kick start the compensation process the lungs will go the opposite direction of the kidneys- because the kidneys are showing alkalosis, the lungs will become acidodic or acidic (pardon my poor spelling). since the kidneys are going in the direction of acidosis (the high CO2 levels mean acidosis), we say it is "partially compensated." this is good-it isn't perfect, yet, in the sense that full compensation hasn't occurred- we would say that full compensation had occurred if the pH went back into the normal range between 7.35 and 7.45.

    last thing: i recommend to anyone struggling with, or new to ICU nursing, that you buy Critical Care Nursing Made Incredibly Easy. It has helped me SOOO much. Also, get a good book on fluid and electrolytes- The "made incredibly easy" people and "dummies" people make a book covering this topic.

    hope this helps!
  2. by   nurse4theplanet
    Did this pt have a hx of CHF? Had they been on long term lasix therapy? Was the hypokalemia being corrected? What did the doctor say when he was notified?

    This pt was only 52, right? Why were they a partial DNR (probably a Do Not Intubate...or DNI...which is what we have at my facility). That seems a little young with only knowing about the pneumonia.
  3. by   emmycRN
    pt was a 82 not 52. He was a partial DNR, or chemical code only (no vent or compressions, only drugs). K was being replaced. No hx of CHF, although he probably was experiencing some mild left heart failure during this admission. No long term lasix. Was put on lasix in hospital due to infiltrates caused from pneumonia and probably some heart failure (although this was not one of his dx). Doc said "I'll be in later" when notified. This was 1.5 hours before shift change so I have no idea what doc did when he arrived, I have not been back to work yet. Also, I didn't mention before that he was on a Cardizem gtt for a fib but had already converted to SR.
    Thanks again for your input, it's very helpful.
  4. by   nurse4theplanet
    Thanks for sharing.
  5. by   TopherSRN
    Quote from emmycRN
    chemical code only (no vent or compressions, only drugs).
    those always make me laugh. Catecholamines do no good sitting in a periphreal or the svc.


    PO2 isnt horrible considering his Hx. You would be surprised at the PO2 some people walk around with though, I wouldn't suggest he buy any green bananas.
  6. by   loafin'
    Actually this is quite simple. I've seen it hundreds of times with chronic hypercapnic's who are very anxious(especially fighting Bipap). You will see the same thing with a client who is a chronic hypercapnic who is place on vent with too high rate. This client's co2 is below his normal. His normal is somewhere around 73 mmhg +or - 2. So it is actually respiratory alkalosis. There is no strange electrolyte imbalance or a drug that caused it. PM me if you would like a more detailed explanation.



    Quote from emmycRN
    82yo male on bipap FIO2 90% with diagnosis of pneumonia. o2 sats WNL.
    ph 7.54
    pco2 51
    p02 64
    hco3 43.6
    BE 18.5

    I am a relatively new ICU nurse and ABG's aren't my strong point. Charge RN and RT said ABG results were respiratory alkalosis due to anxiety and pt fighting bipap. If this is correct why is bicarb so elevated. What is your interpretation of these results?
  7. by   bellarn75
    I think it's also metabolic alkalosis and with respiratory compensation.
  8. by   loafin'
    Quote from BabyM01
    I think it's also metabolic alkalosis and with respiratory compensation.
    I gave my explanation, what is yours. People who have a high bicarb do not slow down respirations to compensate. this is client is a chronic hypercapnic. I don't need any other hx besides abg's to know that.
  9. by   loafin'
    Quote from emmycRN
    K level was low and pt was experiencing muscle twitching, which I know is a symtom of met. alkalosis.
    Thank you all for your input. I hadn't thought about kidneys being the problem.
    I wonder why the experienced RT thought this was a respiratory problem?
    The experienced RT and charge RN were correct. The K+ was low due to the client hyperventilating and lower the hydrogen ion concentration and subsequently pushing K+ from extracellular to intracellar.
  10. by   bellarn75
    Quote from texasnursingstudent
    ph 7.54 ALK
    pco2 51 ACID
    p02 64 indicates that the body does not have enough oxygen in the blood or "hypoxemia."
    hco3 43.6 ALK
    BE 18.5 pretty high base excess there

    partially compensated
    the bicarb is high, as in alkalotic. the pH is also high, that is, it is also alkalotic. this means that we have metabolic alkalosis. to kick start the compensation process the lungs will go the opposite direction of the kidneys- because the kidneys are showing alkalosis, the lungs will become acidodic or acidic (pardon my poor spelling). since the kidneys are going in the direction of acidosis (the high CO2 levels mean acidosis), we say it is "partially compensated." this is good-it isn't perfect, yet, in the sense that full compensation hasn't occurred- we would say that full compensation had occurred if the pH went back into the normal range between 7.35 and 7.45.

    last thing: i recommend to anyone struggling with, or new to ICU nursing, that you buy Critical Care Nursing Made Incredibly Easy. It has helped me SOOO much. Also, get a good book on fluid and electrolytes- The "made incredibly easy" people and "dummies" people make a book covering this topic.

    hope this helps!
    Quote from loafin'
    I gave my explanation, what is yours. People who have a high bicarb do not slow down respirations to compensate. this is client is a chronic hypercapnic. I don't need any other hx besides abg's to know that.

    How TXnursingstudent explains it is how I learned it. If what you explained is more advanced then the basics that I learned then enlighten me some more.
  11. by   nurse4theplanet
    Quote from loafin'
    Actually this is quite simple. I've seen it hundreds of times with chronic hypercapnic's who are very anxious(especially fighting Bipap). You will see the same thing with a client who is a chronic hypercapnic who is place on vent with too high rate. This client's co2 is below his normal. His normal is somewhere around 73 mmhg +or - 2. So it is actually respiratory alkalosis. There is no strange electrolyte imbalance or a drug that caused it. PM me if you would like a more detailed explanation.
    I am a brand new nurse in ICU and I am trying to get a better grip on ABGs. Your explanation is interesting and I want to make sure I understand it.

    Is this something you would see with COPD patients? (That's the first condition that comes to mind where someone is chronically hypercapnic).
    What your saying is that this is definitely a respiratory problem because the pt is used to having a co2 level much higher than what is on the ABG results...(a condition of chronic compensated respiratory acidosis maybe ???). However, when they become anxious and hyperventilate, blowing off more of their co2, it sends them into respiratory alkalosis... even though the CO2 is still at an acidic level and the bicarb is at an alkalotic level. And the low potassium was actually due to the pt hyperventilating and excreting H+ ions.

    Am I understanding you correctly?

    I still don't understand why the bicarb is so high? I assumed the bicarb would be acidotic to correct respiratory alkalosis. However, considering the CO2 is acidotic, I don't know if that would make a difference. Or is the bicarb high simply as a result of the hypokalemia?
  12. by   loafin'
    Quote from asoldierswife05
    I am a brand new nurse in ICU and I am trying to get a better grip on ABGs. Your explanation is interesting and I want to make sure I understand it.

    Is this something you would see with COPD patients? (That's the first condition that comes to mind where someone is chronically hypercapnic).
    What your saying is that this is definitely a respiratory problem because the pt is used to having a co2 level much higher than what is on the ABG results...(a condition of chronic compensated respiratory acidosis maybe ???). However, when they become anxious and hyperventilate, blowing off more of their co2, it sends them into respiratory alkalosis... even though the CO2 is still at an acidic level and the bicarb is at an alkalotic level. And the low potassium was actually due to the pt hyperventilating and excreting H+ ions.

    Am I understanding you correctly?

    I still don't understand why the bicarb is so high? I assumed the bicarb would be acidotic to correct respiratory alkalosis. However, considering the CO2 is acidotic, I don't know if that would make a difference. Or is the bicarb high simply as a result of the hypokalemia?
    You understand exactly. There is a formula called winter's formula for expected pco2 with a given hco3. The abg and client on bipap is a big clue

    Remember HCO3 compensates slower than co2. And actually the bicarb might be slightly lower than client's normal, difficult to know exactly without seeing a normal baseline abg for this client. I wonder if this client had a previous admission with another abg.

    Give yourself more credit, sounds like you have a pretty good grasp. Sometimes we have to think out of the box and not automatically assume that everything we learned in nursing school is law. I mean we know our normal ranges for our lab values, but sometimes when things fall out of range especially abg's, it's not always as simple as using the arrow system(when co2 is up and hco3 is down, it is this...).
    Last edit by loafin' on Feb 21, '07 : Reason: reply was within previous posters quote
  13. by   loafin'
    Quote from BabyM01
    How TXnursingstudent explains it is how I learned it. If what you explained is more advanced then the basics that I learned then enlighten me some more.
    BabyMO1,
    PM me if my reply to asoldierswife05 still did not explain enough.

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