Lecture 19 - AKI

Question 1

Acute kidney injury

Answer 1

Rapid decline in GFR over 2 - 7 days

Rise in serum creatinine

Question 2

CKD staging

Answer 2

1 - eGFR - greater than 90 with proteinuria/haematuria

2. eGFR 60-90 - proteinurian and haematuria
3. eGFR 30 - 60
4. eGFR 15 - 30
5. eGFR less than 15 = ESRF

Question 3

Causes of CKD

Answer 3

20% diabetic nephropathy 
Hypertension
Polycystic renal disease
Renal vasular disease 
Glomerulonephritis
Urinary tract infection

Question 4

Stages of AKI

Answer 4

1. Serum creatinine increases by 1.5 - 2 x
2. Serum creatinine increases by 2 - 3 x
3. Serum creatinine increases by 3+ x

Question 5

What is the least common cause of AKI

Answer 5

Glomerular disease

Question 6

Causes of AKI

Answer 6

Pre renal - decreased renal perfusion

Renal - acute tubular injury

Post renal - Obstruction to urine flow after urine has left the tubules e.g. uteroliathiasis

Question 7

Pre renal cause of AKI

Answer 7

Most common

Decreased renal perfusion e.g. due to BP falling below threshold level therefore decreasing GFR

Kidneys not yet impaired and reversible

Can develop into renal ATI

Question 8

Renal AKI

Answer 8

Acute tubular injury can develop from lack of renal perfusion (pre-renal)

If not treated quickly, kidney cells become ischeamic especially in the proximal tubule as less well perfused

Question 9

Hypoperfusion

Answer 9

Septic shock
Hypovalemic shock
Cardiogenic shock - AKI marker detects CVS disease not kidney disease

• Stenosis of renal artery

Question 10

Causes of renal AKI

Answer 10

Drugs:
NSAIDs
Antibiotics - vancomycin and gentomyocin are nephrotoxic
ACE inhibitors

Sepsis
Rhabdomyolysis
Myeloma
Tubulointestitial disease

Glomerulonephritis - rare

Question 11

AKI causes

Answer 11

Electrolyte disturbance:

• hyperkalaemia
• acute uraemia

Pulmonary oedema

Question 12

GFR in AKI

Answer 12

Not useful as it takes time for creatinine to change