AKI

Question 1

what is it

Answer 1

An abrupt (<48hrs) reduction in kidney
function defined as
– an absolute increase in serum creatinine by
>26.4µmol/l
– OR increase in creatinine by >50%
– OR a reduction in UO

• Can only be applied following adequate fluid
  resuscitation & exclusion of obstruction

Question 2

stage 1

Answer 2

serum cr- Increase >26µmol/L or
Increase > 1.5-1.9 x
reference Cr

UO < 0.5 mL/kg/hr for > 6

Question 3

stage 2

Answer 3

Increase > 2 to 2.9 x
reference SCr

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

Question 4

stage 3

Answer 4

Increase > 3 x reference
SCr or increase to > 354
µmol/L or need for RRT
<0.3 mL/kg/hr for > 24hrs or
12 hrs for anuria

Question 5

risk factors

Answer 5

Older Age
* CKD
* Diabetes
* Cardiac Failure
* Liver Disease
* PVD
surgery
* Previous AKI
Hypotension
* Hypovoleamia
* Sepsis
recent contrast

Question 6

pre renal causes

Answer 6

anything affecting perfusion to kidney
* Reversible volume depletion leading to oliguria &
increase in creatinine

Hypovolaemia
* Haemorrhage
* Volume depletion (e.g. D&V, burns)

Hypotension
* Cardiogenic shock
* Distributive shock (e.g. sepsis, anaphylaxis)

Renal Hypoperfusion
* NSAIDs / COX-2
* ACEi / ARBs- pril , - sartan
* Hepatorenal syndrome

Question 7

complications of pre renal AKI

Answer 7

acute tubular necrosis

most common causes- sepsis and severe
dehydration
rhabdomyolysis
and drug toxicity

Question 8

treatment of pre renal

Answer 8

hydration

Crystalloid (0.9% NaCl) or Colloid (Gelofusin)

• Give bolus of fluid then reassess and repeat as
  necessary
• If >1000mls and no improvement, seek help

stop metformin for diabetic patients

Question 9

renal AKI

Answer 9

Diseases causing inflammation or damage to
cells causing AKI

Vascular
- vasculitis, renovascular disease

• Glomerular
  – Glomerulonephritis
• Interstitial Nephritis
  – Drugs
  – Infection (TB)
  – Systemic (sarcoid)
• Tubular Injury
  – Ischaemia—prolonged renal hypoperfusion
  – Drugs (gentamicin)
  – Contrast
  – Rhabdomyolysis

Question 10

presentation of renal AKI

Answer 10

Nausea & Vomiting
– Itch
– Fluid overload- Oedema, SOB since kidneys not working - bibasal crackles

– Fluid overload/ dehydration, Oedema, Pul oedema, effusions (pleural
& pulmonary)
– Uraemia, pericarditis
– Oliguria

Question 11

rhabdomyalysis

Answer 11

old person lying on floor for couple days - muscle breakdown to myoglobin which is toxic for kidneys

IV drug user

compartment syndrome

Question 12

treatment on renal AKI

Answer 12

rehydrate then inotropes/vasopressors

Stop nephrotoxics
* Dialysis if remains anuric & uraemia

Question 13

complications of renal AKI

Answer 13

Hyperkalaemia
* Fluid Overload (Pulmonary oedema)
* Severe Acidosis (pH < 7.15)
* Uraemic pericardial effusion
* Severe Uraemia (Ur >40)

Question 14

post renal AKI

Answer 14

AKI due to obstruction of urine flow leading to back pressure
(hydronephrosis) and thus loss of concentrating ability

Causes: Stones, Cancers, Strictures, Extrinsic Pressure

dilated renal pelvis

Question 15

TREATMENT OF POST RENAL

Answer 15

Relieve obstruction
* Catheter
* Nephrostomy

refer if need stent

Question 16

hyperkalaemia

Answer 16

Hyperkalaemia = >5.5
* Life threatening hyperkalaemia = >6.5

Question 17

Assessment of hyperkalamia

Answer 17

ECG
– Muscle weakness

Question 18

hyperkalamia treatment

Answer 18

Protect myocardium
– 10mls 10% calcium gluconate (2-3mins)

• Move K+ back into the cells – Insulin (actrapid 10units) with 50mls 50% dextrose (30
  mins)
  – Salbutamol Nebs (90 mins) maybe

Question 19

indications for dialysis

Answer 19

Hyperkalaemia
– >7
– >6.5 unresponsive to medical therapy

• Severe Acidosis
  – pH < 7.15
• Fluid overload
• Urea >40, pericardial rub/effusion
  pericarditis- pain relieved by sitting forward