AKI

Question 1

What are the risk factors for AKI? (6)

Answer 1

Diabetes 
CKD
Cardiac: IHD/CCF
Elderly >75
Sepsis
Medications

Question 2

What medications can be risk factors for AKI?

Answer 2

ACEi
ARBs
NSAIDs
Abx

Question 3

Define stage 1 AKI

Answer 3

Serum creatinine:
1.5-1.9 times baseline
OR
>26.5 micromol/L increase

Urine output:
<0.5ml/kg/h for 6-12 hrs

Question 4

Define stage 2 AKI

Answer 4

Serum creatinine:
2.0-2.9 times baseline

Urine output:
<0.5ml/kg/hr for over 12 hrs

Question 5

Define stage 3 AKI

Answer 5

Serum creatinine:
3 times baseline 
OR 
Increase to >353.6 micromol/L
OR
Initiation of renal replacement 

Urine output:
<0.3 ml/KGH/hr for over 24 hrs
OR
Anuria for over 12 hrs

Question 6

What are the 3 categories of causes of AKI?

Answer 6

Prerenal
Intrinsic
Postrenal

Question 7

List some pre-renal causes of AKI (4)

Answer 7

Hypovolaemia
Decreased cardiac output
Decreased effective circulating volume 
- CCF
- liver failure 
Impaired renal auto-regulation
- NSAIDs
- ACEi/ARB
- Cyclosporine

Question 8

List some intrinsic causes of AKI

Answer 8

Glomerular 
- acute glomerulonephritis 
Tubules and interstitium 
- ischaemia
- sepsis/infection
- nephrotoxins (exogenous and endogenous)
Vascular 
- vasculitis
- malignant hypertension
- TTP-HUS (blood clots)

Question 9

List some post-renal causes of AKI

Answer 9

Bladder outlet obstruction

Bilateral pelvoureteral obstruction (or unilateral obstruction of a solitary functioning kidney)

Question 10

What investigations would you do for AKI?

What are you looking for in each investigation?

Answer 10

1) urine dipstick (look for protein and blood)
2) Daily FBC, U&Es, LFTs, bone profile, CRP, serum HCO3-, CK
3) urine MC+S
4) USS KUB (rule out obstruction)
5) clotting screen and blood film
6) investigate for intrinsic renal disease if indicated

Question 11

What is the management of AKI

Answer 11

Correct fluid levels (IV fluids/diuretics)
-be aware of third space losses
Monitor urine output and daily bloods 
Avoid hyperglycaemia 
Treat underlying cause 
Refer to specialist 
Consider ICU admission

Question 12

What are some supportive managements for AKI

Answer 12

Stop nephrotic medications 
Stop drugs that may increase complications 
- Metformin 
- diuretics 
- antihypertensives
Check drug doses 
Avoid radiograph contrasts

Question 13

What are the indications for renal replacement therapy in AKI?

Answer 13

Hyperkalaemia not responding to Medical therapy
Metabolic acidosis not responding to medical therapy
Fluid overload not responding to diuretics
Uraemic pericarditis
Uraemic encephalopathy
Intoxications