Talk:BUN-to-creatinine ratio

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Shouldn't we clarify what species we're talking about?[edit]

Considering that people might check wikipedia regarding their pet's renal condition, shouldn't it be clarified that all values in this article are for humans only? Dr.queso (talk) 23:08, 14 August 2011 (UTC)

Its obvious this is about humans. 1 in 1000 people will actually look at a BUN:Cr ratio and think... oh my dog has good kidney function. Lets be a little bit realistic here ok? --Smodtactical (talk) 19:23, 2 July 2012 (UTC)


Do H2RA's (cimetidine specifically) decrease BUN:Cr? I always thought that H2RA's block cimetidine secretion into the tubule, so presumably they decrease BUN:Cr? -- Samir धर्म 02:31, 25 June 2006 (UTC)

This article touches on the subject.
Here is a ref (Ixkes MC, Koopman MG, van Acker BA, Weber JA, Arisz L. Cimetidine improves GFR-estimation by the Cockcroft and Gault formula. Clin Nephrol. 1997 Apr;47(4):229-36. PMID 9128789.) that suggests-- cimetidine increases the GFR. So, I'd think it would decrease the BUN/Cr ratio (at least transisently). AFAIK, based on the mass transfer theory I learned, the BUN/Cr ratio changes because the mass generation rates of creatinine and urea are different--I have to find a ref for that though.
My question at the moment is-- is the sensitivity for detecting GI bleeding due to bleeding induced hypovolemia? <--That is my theory... I'm looking for something in the literature to confirm that hunch. Nephron  T|C 03:04, 25 June 2006 (UTC)

Urea:Creatinine ratio[edit]

To me, the term 'ratio' implies the units cancel one another out to create a dimensionless number. Shouldn't the urea to creatinine ratio therefore be 100:1 rather than 1:10 (with creatinine measured in micro moles/L and urea in millimoles/L)? Whyso (talk) 11:28, 15 July 2009 (UTC)

Units changed yet again[edit]

The chart columns are very misleading. First of all, there are no indications whether the first or second column are in SI or US units. Skimming the history, This was changed a few months ago, only to be changed back to its current (erroneous) state.

BUN, to my understanding, is used more in the US. So I'll assume the first column is in US units, and the second is in SI.

If that is the case, then, the second column may be in error. Cr is measured in micro-mol/L, while Urea is measured in millimol/L. Therefore, Ur is three orders of magnitude larger than Cr. It makes no sense, then, to have Cr:Urea of 10:1 -- to have that is to imply that the person has a Cr of 10,000 micromol/L for a Urea of 1 millimol/L.

If there are no further comments to this, I will change it back again to agree to SI units.

Why should a high BUN/creat ratio have a high specificity for GI bleeding, while it should not be caused by protein digest? If it were solely a matter of prerenal renal insufficiency, all causes with comparable volume depletion would cause a similar BUN/creat ratio. Therefore I think the digestion of protein is a major contributor to the increased BUN/creat ratio. —Preceding unsigned comment added by (talk) 10:05, 19 April 2011 (UTC)

Mistake in Interpretation?[edit]

When BUN reabsorption is increased, then this results in a lower amount of BUN in the urine and a lower BUN:Cr ratio in the urine. Because reabsorbed BUN goes back into the blood stream, instead of being excreted in the urine together with creatinine. But the interpretation table says the opposite of this, i.e. BUN:Cr ratio is increased.

And when there is intrarenal injury and reabsorption of BUN back into the blood is reduced due to tubular damage, then this results in greater excretion of BUN in the urine. Which leads to a higher BUN:Cr ratio in the urine. But the interpretation table says the opposite of this. —Preceding unsigned comment added by (talk) 22:51, 2 June 2010 (UTC)

clarification BUN:Cr and Urea:Cr[edit]

The BUN:Cr and Urea:Cr ratios are based upon serum (blood) values and not urine measurements. —Preceding unsigned comment added by Harrisd5917 (talkcontribs) 01:21, 4 June 2010 (UTC)

BUN increase with upper GI bleed[edit]

Can we get some more clarification and research for this section? The argument that high protein intake won't lead to elevated BUN is false I believe. Also, if breakdown from upper GI bleed doesn't elevate BUN but its due to pre-renal state, then why doesn't lower GI bleed also elevate BUN? — Preceding unsigned comment added by Smodtactical (talkcontribs) 19:30, 2 July 2012 (UTC)