Acute Kidney Injury (AKI): The Daily PANCE Blueprint
Which of the following is a cause of acute kidney failure due to prerenal azotemia?
A. Excessive diuresis
B. Urinary tract obstruction
C. Radiologic contrast media
D. Aminoglycosides
E. Rhabdomyolysis
Answer and topic summary
The answer is A. Excessive diuresis
Prerenal azotemia results from decreased renal perfusion, which leads to reduced glomerular filtration rate (GFR) without structural damage to the kidney. The main causes of prerenal azotemia include:
- Hypovolemia: Due to dehydration, excessive diuretic use, hemorrhage, or fluid loss from vomiting, diarrhea, or burns.
- Decreased Cardiac Output: Conditions like congestive heart failure, myocardial infarction, or severe arrhythmias reduce blood flow to the kidneys.
- Systemic Vasodilation: Such as in sepsis, anaphylaxis, or liver cirrhosis (hepatorenal syndrome), where blood vessels dilate and reduce effective perfusion.
- Renal Artery Stenosis or Constriction: Narrowing or blockage of the renal arteries, either from atherosclerosis or vasoconstrictors, decreases blood flow to the kidneys.
- Medications: NSAIDs, ACE inhibitors, and angiotensin II receptor blockers can impair kidney perfusion by affecting renal blood flow and autoregulation.
Incorrect Answers:
- Urinary tract obstruction: Leads to postrenal azotemia, caused by blocked urinary flow, resulting in kidney failure.
- Radiologic contrast media: Causes acute tubular necrosis due to direct nephrotoxicity, categorized as intrinsic renal disease.
- Aminoglycosides: Exogenous nephrotoxins that induce acute tubular necrosis, an intrinsic renal condition.
- Rhabdomyolysis: Leads to intrinsic renal failure due to myoglobin release, causing acute tubular necrosis.
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Smarty PANCE Content Blueprint Review:
Covered under ⇒ PANCE Blueprint Renal System ⇒
