Bicarb

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anbuitachi

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Have attendings that love to asking me what is the patient's preop bicarb prior to starting the case.. My question for you all is what do you do with this information? A patient comes in otherwise fine for elective case, but has kidney disease with bicarb if 13. Are you cancelling the case? Are you giving bicarb during the case? How do YOU change your management based on this information?
 
CKD shouldn't decrease your bicarb that much. If it does ... It's probably due to RTA. A bicarb of 13 in my opinion should be delayed until a more thorough workup is completed. I would at a minimum get an abg, cmp, LFTs, and better history.

My sickest patients after induction of anesthesia were the ones with a severely depressed bicarb. We didn't expect the decompensation until they went to sleep.
 
bad CKD/ESRD. so you would cancel the case if the bmp shows a bicarb of 13. K normal. everything else normal. dialyzed yesterday.
i would definitely be concerned if it's an acute process.. and im guessing they probably wouldnt be totally fine looking if its acute.

yea i think low bicarb is correlated to higher mortality.. but would giving bicarb intraop change things..?
 
anbuitachi said:
Have attendings that love to asking me what is the patient's preop bicarb prior to starting the case.. My question for you all is what do you do with this information? A patient comes in otherwise fine for elective case, but has kidney disease with bicarb if 13. Are you cancelling the case? Are you giving bicarb during the case? How do YOU change your management based on this information?
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I look for compensatory alkalosis, usually for undiagnosed chronic respiratory acidosis (COPD, OSA). At a bicarb of 13, I would definitely get at least a venous gas preop and start looking for a cause.

If the patient has ESRD and was dialyzed yesterday, and the bicarb is 13, something is fishy. I would try figuring out the reason first.
 
Agreed. My main interest in bicarb levels pre op is the level of indication it provides regarding level of chronic CO2 retention, assuming they aren’t on high levels of chronic furosemide. Similar to Hb levels and chronic hypoxia (but this relationship is FAR less robust).
 
FFP said:
I look for compensatory alkalosis, usually for undiagnosed chronic respiratory acidosis (COPD, OSA). At a bicarb of 13, I would definitely get at least a venous gas preop and start looking for a cause.

If the patient has ESRD and was dialyzed yesterday, and the bicarb is 13, something is fishy. I would try figuring out the reason first.
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what if the patient has diagnosed COPD, OSA. and you see a bicarb of 13. would you do anything other than it tells you patient has bad OSA/COPD
 
anbuitachi said:
what if the patient has diagnosed COPD, OSA. and you see a bicarb of 13. would you do anything other than it tells you patient has bad OSA/COPD
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As someone mentioned poor respiratory function usually associated with OSA or COPD would have an elevated bicarb because of the chronic CO2 retention. In that case I would try to optimize the patient periop as much as possible. Advocate for a regional block. If possible do the case under regional. Duonebs in preop holding. Take a listen to lung sounds preop. Do a better history to establish his baseline and any recent hospitalizations. Make sure he's not having a COPD exacerbation. If a longer case under general I would consider an arterial line. In the OR I would not bring the ETCO2 to 35. If the CO2 were chronically elevated trying to "make the numbers perfect" would make patient alkalotic.


Your patient has a metabolic acidosis. And you have to figure out why. If chronic or acute. And you need to make sure this is all chronic rather than assume it is. RTA, chronic bicarb losses from enterocut fistulas, patient with neobladders, and NGTs would be examples of chronic bicarb losses which I would proceed.

Acute processes I would delay for is uncompensated AKI on CKD/need for more dialysis, acute liver injury, sepsis, acute CHF.

no I would not necessarily give bicarb. The bicarb is an indicator that something is going on. And you should figure out what it is rather than try to make the numbers perfect. Giving bicarb would just make your numbers look better without fixing the underlying issue. And can even worsen your CO2. I would only give bicarb for patients in severe metabolic derangement with pH around 7.0-7.2 who are requiring high pressors etc.... I.e. Perforated viscus.
 
anbuitachi said:
Have attendings that love to asking me what is the patient's preop bicarb prior to starting the case.. My question for you all is what do you do with this information? A patient comes in otherwise fine for elective case, but has kidney disease with bicarb if 13. Are you cancelling the case? Are you giving bicarb during the case? How do YOU change your management based on this information?
Click to expand...

With a bicarb of 13, even if I strongly suspected esrd, I would still recheck a chemistry, mag, phos, get a white count, lactate, abg, and make sure there’s not a significant gap acidosis or other metabolic process going on. Ckd 4 and ESRD should usually be on TID PO bicarb if required so I’d wanna know why this person wasn’t
 
Lol oops was not thinking clearly! Definitely high not low in copd lol

But yea its not unfrequent i see patients with pretty low bicarb with ESRD. Just the other day i had 3 ESRD patients and all 3 had bicarbs <15, with other labs in pretty much normal range
 
Well I asked my buddy since you peaked my curiosity. So let’s say some poor soul is born with RTA and now has gotten fat enough to get bad OSA or smoked enough to have bad COPD. Now what?
Her response was, unless the RTA and COPD is severe there will be some compensation especially with treatment. But RTA is so rare that the only times she sees numbers that low are with ESRD patients. But apparently these patients can compensate to both disorders if not severe.
 
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