More confusion about abnormal labs

[mlauren]

First I'll fill you in on my patient...Male, 51 years old. Admitting Diagnoses are interstitial lung disease and pneumothorax. He reported having a cough for past 5 years, productive and worse in mornings. Also reported increased chest discomfort for past several months. But he has not had a lung biopsy, so they are unsure what exactly is going on with that. They just know he has some fibrotic changes in his right lung. So anyways, he also has Crohn's (33 years) and a Ileostomy. He isn't having any problems with bowels. He has Osteoporosis and gout. He had a PE in 94' after a procedure. Other history...bronchitis, pneumonia, abd hernia, GERD, cataracts. During my clinical day he had a sinus/brady rhythm and his heart rate stayed between 54-60. Overall his vital signs were normal. No signs of anything wrong, other than the low HR. He was having trouble with breathing, SOB, and pain when he coughed, breathed deep, and moved. But O2 sat and RR were good and he was being weaned off of oxygen when I left. He had a chest tube that had drained 870ml in about 2 days, Serosanguinous.

His Hgb (12.9) and RBCs (4.33) were low. His CO2 was low as well. (20) And I'm trying to figure out if it was because of blood loss, anemia, or something else.

Also his BUN (26) & serum creatinine (1.53) were high and albumin (2.9) & GFR (48) were low. Everything that I have read points to kidney failure or some kind of renal problem when it comes to the above lab results. I'm confused about why he would have kidney damage and why he isn't being treated for it. I don't know a whole lot about this kind of thing since this is the first semester I've really had to interpret these labs. It's very confusing to me and I find myself completely lost, especially with a patient who's diagnosis isn't even certain. Does anybody have any advice or ideas for what might be the problem with this patient? It's driving me crazy.

[bear14]

Ok, now I am intrigued. Can you explain the venous CO2 measuring bicarb? I am still in school and we have never been taught that? Also, how did you come to dx of dehydration? Thanks :)!

[KelRN215, BSN, RN]

Ok, now I am intrigued. Can you explain the venous CO2 measuring bicarb? I am still in school and we have never been taught that? Also, how did you come to dx of dehydration? Thanks :)!

Serum Total Carbon Dioxide - Clinical Methods - NCBI Bookshelf

When you learn about CO2 in school, it is typically in the context of arterial blood gases which measure pCO2.

Here's an old thread where it was explained as well:

https://allnurses.com/emergency-nursing/co2-and-hydration-229959-page3.html

When looking at blood chemistries, a low CO2 indicates acidosis while when looking at arterial blood gas, a high pCO2 or a low HCO3 indicates acidosis.

Clinically, this patient seems to be somewhat dehydrated. His BUN and Cre are mildly elevated and his GFRs are a little low. He has Chrohn's with an ileostomy. What kind of stool comes out of an ileostomy? What part of the intestines is in charge of water reabsorption? What happens when someone has an ostomy before this? He also has a chest tube draining a fair amount of fluid. OP mentions nothing about what type of hydration he is receiving nor his urine output which are important pieces of the puzzle though...

[nurseprnRN, BSN, RN]

While BUN elevates with dehydration and will resolve with hydration, creatinine doesn't and won't, which is why it's a more sensitive measure of renal failure.

In COPD with chronic hypercarbia, an elevated CO2 is no longer the respiratory driver, hypoxia is. So when CO2 goes higher d/t pneumonia that will not be the cause of his hyperventilation, the decreasing O2 will.

CO2 doesn't decrease as a result of being hyperoxygenated, because O2 transport and CO2 transport are two independent variables. CO2 will drop with hyperventilation, though.

[mlauren]

These labs can be very simply explained. The low H&H are from a combined Crohn's disease and the output in the chest tube. Serosangious is blood tinged correct? So your losing blood from the chest tube as well. CO2 is from his disease in the early stages. In COPD patients CO2 tends to be high, but with him having PNA as well, he will be hyperventilating trying to compensate for this. His CO2 levels will eventually go back up in the mid 40's to low 50's due to his COPD. It would be interesting to see what his ABG's are to see his actual pH, p02 and pCO2 levels. His Cr and BUN are elevated due to dehydration. Hope this helps![/quote']

Ok so I get that H&H would be decreased if there is blood loss. But if the high bun/creatinine is due to dehydration then wouldn't the H&H increase?

[mlauren]

Work-up for a cause of all of the above-- interstitial fibrosis renal involvement, anemia, cardiac probs-- lupus, drug toxicity, poisoning?[/quote']

I know anemia could cause low H&H but wouldn't his iron levels be low? Unless it were pernicious anemia and then his b12 and folic acid would be low as well and they were not.

[Esme12, ASN, BSN, RN]

I know anemia could cause low H&H but wouldn't his iron levels be low? Unless it were pernicious anemia and then his b12 and folic acid would be low as well and they were not.

LOOK at your assessment....you already have your answer.....critically think this through

chest tube that had drained 870ml in about 2 days,

was that drainage bloody?

he also has Crohn's (33 years)

Crohn's disease: Symptoms - MayoClinic.com

[Esme12, ASN, BSN, RN]

Ok so I get that H&H would be decreased if there is blood loss. But if the high bun/creatinine is due to dehydration then wouldn't the H&H increase?

technically it will raise some...but IV hydration will cause it to be more reflective of an actual count

[nurseprnRN, BSN, RN]

While BUN elevates with dehydration and will resolve with hydration, creatinine doesn't and won't, which is why it's a more sensitive measure of renal failure.

Never had occasion to quote myself!