Final answer:
In pre-renal acute kidney failure, the BUN: Creatinine ratio is typically greater than 20:1, making option c (20:1 - 30:1) the correct answer.
Step-by-step explanation:
In pre-renal acute kidney failure, the BUN (blood urea nitrogen): Creatinine ratio is typically elevated, often greater than 20:1. When comparing the options provided in the question, the correct answer is c. 20:1 - 30:1.
This is reflective of a decrease in renal perfusion or effective blood volume without intrinsic kidney damage, leading to a disproportionate elevation of BUN relative to creatinine. This is because urea reabsorption is increased in response to hypoperfusion, whereas creatinine, which is not reabsorbed, does not increase to the same extent.
The BUN (blood urea nitrogen) and creatinine levels are used to assess renal functions. In Pre-Renal Acute Kidney Failure, the BUN level is significantly higher compared to the creatinine level, resulting in a higher ratio.