Acute renal injury

Question 1

AKI definition

Answer 1

Abrupt decrease in glomerular filtration= Imbalances in electrolyte, fluid and acid-base control.

Increased creatinine clearance or decreased urine output

Question 2

Stage 1 AKI

Answer 2

Creatinine:

• 1.5-1.9 from baseline
• > /=0.3

Urine output:
- 0.5, 6-12 hours

Question 3

Stage 2 AKI

Answer 3

Creatinine:
2-2.9x the baseline

Urine:
- 0.5, >/= 12 hours

Question 4

Stage 3 AKI

Answer 4

Creatinine:

• 3x from baseline
• Increase of 4

Urine:

• Anuria for 12 hours
• 0.5, >/= 24 hours

Any requirement for initiation of renal replacement therapy.

In patients younger than 18 years, a decrease in estimated GFR to less than 35 mL/minute/1.73 m2

Question 5

Risk factors for AKI (6)

Answer 5

• CKD
• Diabetes M.
• Coronary artery disease, heart failure
• Pulmonary disease
• Chronic liver disease
• Critical illness
• Intense prolonged exercise

Question 6

Pre-renal causes of AKI (13)

Answer 6

Hypoperfusion/ hypervolemia (most common)

• Haemorrhage
• Sepsis
• Vomiting
• Diarrhoea
• Dehydration
• Burns
• Diuresis/ Diuretics
• Cardiac failure

Drugs:

• NSAIDs
• ACEi
• ARBs
• Amphotericin B (antifungal)
• Noradrenaline

Question 7

Drugs that cause AKI

Answer 7

• NSAIDs
• ACEi
• ARBs
• Amphotericin B (antifungal)
• Cylcosporin
• Noradrenaline

Question 8

Renal causes of AKI (16)

Answer 8

• Most common: Hypoperfusion, hypovolemia, drugs (NSAIDs, ACEis, ARBs)

Others:

• RA thrombosis
• RA emobolism
• RA stenosis

Small renal vessels

• Artheroembolism
• Haemolytic uremic syndrome
• Malignant hypertension (MT)

Vascular disorders:

• Vasculitis
• Scleroderma
• MT

Glomerulus:
- Glomerulonephritis

Nephrotoxic:

• Increase Hb, myoglobin, bilirubin
• Uric acid crystals
• Drugs

Question 9

Post-renal causes of AKI (16)

Answer 9

Prostate hypertrophy

Urethral obstruction: suture, phimosis

Bladder, prostate and cervical cancer

Stones, crystal, clots, tumours

Neurogenic bladder

Retroperitoneal fibrosis