Which option is NOT a renal or intrarenal cause of acute renal failure?

Which option is NOT a renal or intrarenal cause of acute renal failure?

• A. Injury from trauma
• B. Nephrotoxic drugs
• C. Nephrotic infection
• D. Renal stones

Answer: (D)

Acute kidney injury is categorized by where the injury occurs: pre-renal (outside the kidney), intrarenal (within the kidney tissue), and post-renal (urinary tract obstruction). Renal stones cause a blockage that obstructs urine flow along the urinary tract, which is a post-renal mechanism. That means it’s not damage to the kidney tissue itself, so it’s not an intrarenal cause. The other scenarios describe direct kidney injury: trauma can injure kidney tissue, nephrotoxic drugs damage the tubules/interstitium, and infections that involve the kidneys can affect the glomeruli or interstitium, all intrarenal processes.

Acute kidney injury is categorized by where the injury occurs: pre-renal (outside the kidney), intrarenal (within the kidney tissue), and post-renal (urinary tract obstruction). Renal stones cause a blockage that obstructs urine flow along the urinary tract, which is a post-renal mechanism. That means it’s not damage to the kidney tissue itself, so it’s not an intrarenal cause. The other scenarios describe direct kidney injury: trauma can injure kidney tissue, nephrotoxic drugs damage the tubules/interstitium, and infections that involve the kidneys can affect the glomeruli or interstitium, all intrarenal processes.