Final answer:
In Post-Renal acute kidney failure, the BUN:Creatinine ratio is typically greater than 20:1 due to obstruction in the urinary tract leading to increased BUN reabsorption.
Step-by-step explanation:
Post-Renal acute kidney failure can lead to an elevated BUN (blood urea nitrogen): Creatinine ratio due to the inability of the kidney to properly eliminate waste products.
In Post-Renal acute kidney failure, the typical BUN:Creatinine ratio is >20:1, often much higher because BUN reabsorption increases as urine flow decreases due to the obstruction.
Examples of conditions leading to Post-Renal failure include medication interference with bladder emptying, prostate issues, kidney stones, abdominal malignancies, or an obstructed urinary catheter.