Acute Kidney Injury

Question 1

what is acute kidney injury?

Answer 1

This is when there’s a rapid decline in kidney function - leading to a reduction in the GFR.

Question 2

What is the criteria for acute kidney injury?

Answer 2

• <0.5ml/kg/hr for 6 hours
• > 50% increase in serum creatinine for 7 days
• > 25 increase in creatinine in 48hrs

Question 3

what are the stages of acute kidney injury?

Answer 3

stage 1: 50-99% increase in creatinine in 7 days, >0.5ml/kg/hr for 6 hours.
Stage 2: 100-199% increase in creatinine in 7 days, >0.5ml/kg/hr for 12 hours.
Stage 3: >200% increase in creatinine in 7 days, >o.3ml/kg/hr for 24hrs OR ANURIA

Question 4

what is the main cause of acute kidney injury?

Answer 4

Pre renal causes (most commonly hypotension)

Question 5

What are the pre-renal causes of acute kidney injury?

Answer 5

HYPOTENSION:

Dehydration, Vomiting, diarrhoea, heart failure, hypotension (shock), sepsis

Question 6

What are the intrinsic (renal causes) of acute kidney injury?

Answer 6

Usually due to ischaemia of the kidneys - glomerulonephritis, renal ischaemia, nephrotoxic drugs. acute tubular necrosis - most common renal cause.

Question 7

What are the post-renal causes of acute kidney disease?

Answer 7

Benign hyperplastic prostate, tumour, strictures, renal stones (must be BILATERAL) - unilateral kidney stones which only affect one kidney won’t cause AKI because the other kidney will be able to compensate for it.

Question 8

What are common nephrotoxic drugs?

Answer 8

NSAIDs, ARBs, ACE inhibitors, loop diuretics.

Question 9

what are risk factors of acute kidney injury?

Answer 9

Diabetes, heart failure, liver disease, CT scans.

Question 10

What are the complications of acute kidney injury?

Answer 10

HYPERKALAEMIA, fluid overload, metabolic acidosis, uraemia - encephalopathy or pericarditis, chronic kidney disease.

Question 11

when is an ultrasound indicated?

Answer 11

If an obstructive cause is suspected, otherwise it’s not.