Acute Kidney Injury (AKI)

Question 1

define AKI

Answer 1

abrupt (<48 hours) reduction in kidney function due to tubular cell death

Question 2

classification of AKI

Answer 2

1. pre-renal
2. renal
3. post-renal

Question 3

stages of AKI

Answer 3

1-3

Question 4

stage 1 of AKI

Answer 4

serum creatinine increase >26 umol/L or increase > 1.5-1.9

UO <0.5mL/kg/hr for > 6 hours

Question 5

stage 2 of AKI

Answer 5

serum creatinine increase >2-2.9

UO <0.5mL/kg/hr for >12 hours

Question 6

stage 3 of AKI

Answer 6

serum creatinine increase >3 or need for RRT

UO <0.3mL/kg/hr for >24 hours or 12 hours anuria

Question 7

pre-renal causes of AKI

Answer 7

hypovolaemia
hypotension
infection
renal hypoperfusion (NSAIDs, COX2, ACEI/ARB)

Question 8

what can untreated pre-renal AKI lead to?

Answer 8

acute tubular necrosis

Question 9

diagnosis of acute tubular necrosis

Answer 9

muddy brown casts of epithelial cells

Question 10

diagnosis of pre-renal AKI

Answer 10

fluid challenge for hypovolaemia using crystalloid or colloid

Question 11

what renal AKI?

Answer 11

inflammation/ damage to cells

Question 12

causes of renal AKI

Answer 12

Vascular= vasculitis, renovascular disease
Glomerular= glomerulonephritis
Interstitial nephritis= drugs, infection (TB) and systemic (sarcoid)
Tubular injury= ischaemia, drugs (gentamicin), contrast and rhabdomyolysis

Question 13

what is post-renal AKI

Answer 13

obstruction

Question 14

management of post-renal AKI

Answer 14

catheter
nephrostomy
ureteric stenting

Question 15

presentation of AKI

Answer 15

non-specific= anorexia, weight loss, fatigue, lethargy, N&V
fluid overload= SOB, oedema, hypertension, effusion
uraemia= itch, pericarditis
oliguria

Question 16

diagnosis of AKI

Answer 16

U&Es, FBC, clotting screen
check BP
urinalysis
USS for obstruction
immunology

Question 17

management of AKI

Answer 17

perfusion= fluid resuscitate and consider inotropes/vaspressors
dialysis if anuria and uraemia
stop nephrotoxics

Question 18

what nephrotoxics should be stopped in AKI?

Answer 18

NSAIDs
ACEI/ARBs
diuretics
gentamicin
contrast
trimethoprim
potassium-sparing diuretics

Question 19

complications of AKI

Answer 19

hyperkalaemia
fluid overload
severe acidosis
uraemic pericardial effusion

Question 20

what does hyperkalaemia cause?

Answer 20

cardiac arrhythmias

Question 21

assessment of hyperkalaemia

Answer 21

ECG

muscle weakness

Question 22

management of hyperkalaemia

Answer 22

protect myocardium with calcium gluconate
move K+ back into cells with insulin with dextrose and salbutamol
prevent absorption from GI tract with calcium resonium