Acute Kidney Injury

Question 1

Creatinine

Answer 1

Waste product of the metabolism of creatine by muscles. Passes to the kidneys where it is excreted

Question 2

Urea

Answer 2

Ammonia is converted to urea during the ‘urea cycle’ in the liver. It then passes to the kidneys where it is excreted.

Question 3

What does elevated urea indicate?

Answer 3

Dehydration
GI bleeding
Increased protein breakdown (trauma, infection, malignancy)
High protein intake

Question 4

What does reduced urea mean?

Answer 4

Malnutrition
Liver disease
Pregnancy

Question 5

Acute Kidney Injury Classification

Answer 5

> 50% rise in serum creatinine from baseline
<0.5 mL/kg/h urine output for 6 hours

Question 6

Management for AKI

Answer 6

Urine dipstick
Bloods
VBG
Fluid balance chart (requires catheterisation)
Stop nephrotoxic drugs and stop/dose-reduce renal excreted drugs

Question 7

Causes of pre-renal AKI

Answer 7

Renal hypoperfusion
Hypovolaemia/sepsis
Renovascular disease
Cardiorenal failure

Question 8

Causes of renal (intrinsic) AKI

Answer 8

Acute tubular necrosis
Acute interstitial nephritis
Glomerulonephritis
Thrombotic microangiopathy

Question 9

Causes of post-renal AKI

Answer 9

Ureter obstruction - ureteric calculi, vesicoureteric reflux, ureteric stricture, tumour, extrinsic compression
Bladder obstruction - neurogenic bladder, bladder calculi, tumour
Urethra obstruction - benign prostatic hypertrophy, prostate cancer, stricture, blocked catheter