Home Forums Blood Urea Nitrogen, Why?

I am closing my in office lab over losing staff. Not profitable enough to go thru training another. And running an office lab is an analog endeavour in a digital world with ehrs.

Anyway, I am making up orders for labs to give to patients, and realized that I cannot remember when I needed a BUN to make a decision. We track Creatinine closely, since rheumatologists can kill or fail to save a lot of kidneys if we're not careful. I'm writing a database to track orders and results, and I wonder if I should even allow an option of ordering a BUN.

What are the clinical scenarios that need the BUN as well as the Creatinine? I'm not worried about dehydration in my practice.

Just too lazy to research this in private, and too old to care about exposing my ignorance, so thought I'd ask for advice.

Hi Dan,

I never worry about exposing my ignorance!

In a family practice, primarily geriatric, there are definitely times that the BUN is helpful. When a BUN is disproportionately elevated (typically greater than 20 times the creatinine) I usually think dehydration, although occasionally upper G.I. bleeding can do this too. I believe the protein load of the reabsorbed blood is the mechanism for this. So I find it useful to have.

In your practice, I would think it might be helpful in two scenarios. One is to help to detect upper G.I. bleeding (although you're probably following hemoglobin, so most likely redundant), the other would be to detect early dehydration in an elderly population.

Interesting, the question of the general utility of creatinine versus BUN and creatinine. The freestanding x-ray facility locally only wants a creatinine before administering intravenous contrast, the hospital wants both BUN and creatinine.

As a similar question, out of habit I order TSH and T4. Is there justification for ordering the T4 as well, or is the TSH sufficient?

Thanks.

Gene

I will order a TSH with reflex, so if TSH normal a free T4 will not be done.
BUN also helpful to predict severity of acute pancreatitis.

I am usually ordering CMP and BMP labs so I automatically get both. I use both to evaluate the overall picture of the kidney health. Of course, these are indirect indicators. An elderly lady with a Cr of 1.3 may have poor kidney function, as her muscle mass is so low and she really is hanging on to a large percentage of her Cr by failing to clear it. You are right, generally much more useful than the BUN, but we get both together.

@Dan,

I suppose if it is one of those things where it comes with the BMP and does not cost more, then why not. Otherwise it has never helped me which includes residency and PICU. I find ratios such as lactate to pyruvate and BUN/Cr.

Did you say rheumatologist or nephrologist.

I'm with gene. I never worry about exposing my arrogance.

JamesNT

Wait a minute....


JamesNT

I deleted mine. You may want to delete yours so it makes sense. Sorry.

My reason for an office lab was always to make sure I wasn't harming the patient with the NSAIDs and DMARDs I prescribe. CBC, simple chemistries, ESR, and Urine are not too hard to handle with a practice. It used to be profitable, now it pays for staff wages and health benefits and is a convenience that my patients will miss, as we give up phlebotomy and send outs too.

So if we all gave up ordering BUNs, could we save Medicare from bankruptcy and prevent the seas from rising?

Another frugal thought. Do we really need both ALT or AST to specifically monitor healthy appearing patients for liver toxicity from drugs? What's the cost to benefit ratio of ordering both.

I am missing something. What is the difference between being profitable and paying the staff's wages and health benefits? Does it really may for that? That would be awesome.

I think it is all specific to each doctor. I don't need everything on the differential. Maybe the MCV and RDW and even that isn't generally necessary. Some know the difference between alcoholic cirrhosis and not and other things, but for me in peds it doesn't help much.

Finally, you have to find out if removing the RDW from CBC makes it cheaper. If so, only add it on when the patient is anemic.

AC and its ilk are endangering the physician's office lab as our small volume machines can't interface with the ehr directly. To keep up with the Joneses, we manually enter the results so a program can manipulate the data to impress patients adequately.

Also, hospitals buying practices close the office labs to funnel the tests to the hospital lab for greater profits since volume is always the key. But that didn't affect me.

Spotting trends, systemic and non-systemic errors, and keeping lab machines in calibration is not something the average MA or phlebotomist can do. Lab techs are more expensive, maybe less flexible helping do MA tasks. Getting the right staff is essential.

Ten years ago, my lab paid me about $25k/year. Last year, $3k. If you have the space, right staff, and are bored, an office lab is a great convenience for your patients.

Dan,
Good question. I use BUN all the time in the inpatient setting, spec in diagnosing acute kidney injury. Outpatient not so helpful, although once in a while it really helps.
BUN is also part of the MDRD GFR and CKD EPI GFR equations, which improve our evaluation of renal disease.
As part of a panel, it's cost is literally pennies, and I suspect it would cast more to remove it from the panels than it would save by doing so.

Nice information shared here for blood urea. I would like to know more on this topic.

Why would an exporter of pharmaceuticals want to know anything about BUN.

See my post on Canada Pharm

Chris,

Can you give a link with those? Thanks?

I didn't get to read it, but the post by jack ross seems a bitch spammy. At least he could explain why his site is useful. I didn't ban him, cause I thought an explanation would be fun.