Renal

Question 1

Define acute kidney injury. What are the causes of AKI? How does urine output change with time following AKI?

Answer 1

1. Acute kidney injury is
   - Acute reduction in renal function
   - Usually due to tubular necrosis/insult
   - Potentially reversible
2. Causes of AKI
   - Pre-renal (Hypoperfusion): Dehydration, hypovolaemia, shock
   - Renal (ATN causes): Drugs (NSAIDs, aminoglycosides, aspirin), contrast, heavy metals, myoglobin
   - Post-renal (Obstruction): Stones, pyelonephritis, tumor, clot
3. Changes in urine output with AKI
   - Initiation phase: Oliguria
   - Maintenance phase: Persistent oliguria or goes into Anura
   - Recovery phase: Polyuria