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Can someone tell me what the levels of bun/creatinine are for Prerenal, renal, postrenal conditions?



bun/creatinine are for Prerenal - > 20, renal- <15, postrenal->15


As you say, these are the values I know of:

Pre-renal: Bun/Creatinine > 20
Renal: Bun/Creatinine < 20
Postrenal: Bun/Creatinine ????? (not sure). You say it's 15. Is it <15, >15, or just 15?

I heard there have been qs on First Step just on this concept.


Obstruction should result in urea rising faster than creatinine, so it should be >15 (assuming that 15 is the value); I just remembered it in terms of increased or decreased (with a reference range of 10-20).

(Though prerenal disorders usually result in a ratio over 20).


Bela Postrenal: Bun/Creatinine is > 15, more than renal, and less than prerenal. In case of dif. diagnosis of pre- and post- renal you need some additional information, bcouz in that both cases there are increase in b/c ratio.


The key in postrenal are the BUN will be really high, and creatinine will be high but not as high as renal, because backflow will cause BUN buildup due to obstruction.

So, classic presentation:

60 BUN/2 creatinine (WITH OBVIOUS ABNORMAL EABV) = prerenal
60 BUN/6 creatinine (ANYTIME) = renal
60 BUN/2 creatinine (WITH NORMAL EABV or signs of obstruction) = postrenal


thnx a lot guys!

What is the main determinator of the renal function, Bun or creatinine? wink




U're right smiling face

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