Question
Which one of the following parameters suggests pre-renal azotemia?
| A. |
Renal tubular epithelial cell casts
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| B. |
Granular casts in urine sediment
|
| C. |
Hyaline casts in urine sediment
|
| D. |
Fractional excretion of sodium > 1%
|
Show Answer
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Correct Answer � C
Explanation
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|
Pre-Renal Azotemia:
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- Pre-renal azotemia is caused by decreased renal perfusion (e.g., hypovolemia, heart failure). The kidney structure remains intact.
- It is reversible if the underlying cause is corrected.
Key Features Suggesting Pre-Renal Azotemia:
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- Hyaline casts: These are typically observed in pre-renal azotemia due to dehydration and low urine flow, causing precipitation of Tamm-Horsfall proteins.
- Fractional excretion of sodium (FENa): It is usually
Why Other Options Are Incorrect:
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- Renal tubular epithelial cell casts (A): Suggestive of acute tubular necrosis (intrinsic renal pathology).
- Granular casts (B): Indicative of intrinsic renal disease, such as acute tubular necrosis.
- FENa > 1% (D): Found in intrinsic renal failure where sodium excretion is impaired.
