AKI

Question 1

What is AKI defined as?

Answer 1

an abrupt (<48hours) reduction in kidney fucntion- increase in creat by >26.4; increase in creat >50%; reduction in UO

Question 2

What must happen before AKI is diagnosed?

Answer 2

following adequate fluid resus and exclusion of obstruction

Question 3

What are the 3 main causes of pre-renal AKI?

Answer 3

hypovolaemia; hypotension and renal hypoperfusion

Question 4

What are causes of hypovolaemia?

Answer 4

haemorrhage; volume depletion eg D&V; burns

Question 5

What are causes of hypotension?

Answer 5

cardiogenic shock; distributive shock- sepsis or anaphylaxis

Question 6

What can cause renal hypoperfusion?

Answer 6

NSAIDs; ACEi

Question 7

What is pre-renal AKI?

Answer 7

reveresible volume depletion leading to oliguria and incrase in creatinine

Question 8

What is normal UO?

Answer 8

0.5ml/kg/hour

Question 9

How much of the cardiac output do the kidneys receive?

Answer 9

20%

Question 10

What does untreated prerenal AKI lead to?

Answer 10

acute tubular necrosis

Question 11

What are causes of acute tubular necrosis?

Answer 11

decreased renal perfusion- sepsis; severe dehydration

rhabdomyolysis and drug toxicity

Question 12

How is prerenal AKI treated?

Answer 12

fluid status and if dry- fluid challenge

Question 13

What is renal AKI?

Answer 13

diseases causing inflammation of damage to renal cells

Question 14

What are the main categories of renal AKI causes?

Answer 14

vascular; glomerular; interstitial nephritis; tubular injury

Question 15

How do NSAIDs cause interstital nephritis?

Answer 15

COX inhibitor causes preferential conversion of arachidonic acid to leukotrienes which may then activate helper T cells

Question 16

What is seen on bloods with drug-induced AIN?

Answer 16

eosinophilia and IgE

Question 17

What are the risk factors for developing AKI?

Answer 17

age >75; CKD; cardiac failure; PVD; DM; sepsis; poor fluid intake/increased losses; hx of urianry symptoms

Question 18

What are hte causes of interstital nephritis?

Answer 18

drugs; TB; sarcoid

Question 19

What are the causes of tubular injury?

Answer 19

ischaemia- prolonged renal hypoperfusion; drugs (gentamicin); contrast; rhabdomyolysis

Question 20

What are the signs of AKI?

Answer 20

fluid overload; uraemia and itch; pericarditis; oliguria

Question 21

What are hte initial investigations for AKI?

Answer 21

U&Es- K!; FBC and coag screen- anaemia- CKD; myeloma; abnormal clotting- sepsis; urinalysis; USS- obstruction, size; immunology; protein electrophoresis

Question 22

What are the indications for urgent renal biopsy?

Answer 22

suspected reapidly progressive GN; positive immunology and AKI

Question 23

How can you ensure a renal biospy will be safe?

Answer 23

normal clotting; normotensive; no hydronephrosis

Question 24

What is the treatment of AKI?

Answer 24

establish good perfusion pressure; treat underlying cause- abx if sepsis; stop nephrotoxics

Question 25

When should dialysis be give nwith AKI?

Answer 25

if patient remains anuric and uraemia; pericardial effusion; hyperalaemia; severe acidosis; fluid overload

Question 26

What are hte life-threatening complications of AKI?

Answer 26

hyperkalaemia; fluid overload; severe acidosis; uraemic pericardiac effusion; severe uraemia

Question 27

What causes post-renal AKI?

Answer 27

obstruction

Question 28

What is the treatment of post-renal AKI?

Answer 28

relieve obstruction by catheter or nephrostomy- refer to urology

Question 29

What is hyperkalaemia?

Answer 29

> 5.5

Question 30

What is life-threatening hyperkalaemia?

Answer 30

> 6.5

Question 31

How is hyperkalaemia assessed?

Answer 31

ECG; muscle weakness