Acute Kidney Injury

Question 1

When is a patient in AKI?

Answer 1

When there serum creatinine rises by 26micromol/L in 48 hours or by 50% over 7 days

urine output may fall below 0.5ml/kg/hour for more than 6 hours

This is AKI stage 1

Question 2

When is a patient in AKI stage 2

Answer 2

when serum creatinine is 2-2.9 greater than baseline and bring output is below 0.5ml/kg/hour and is maintained for more than 12 hours.

Question 3

When is a patient in AKI stage 3

Answer 3

When there serum createnine is >3 times baseline or has reached 354micromol/L or the patient needs dialysis. AKI staged three can also be characterised by a urine output of <0.3ml/kg/hour for more than 24 hours or no urine at all for 12 hours.

Question 4

AKI can be pre - renal. What does this mean and how is it caused and treated?

Answer 4

Renal perfusion

This could be due to haemorrhage, dehydration, hypovolaemia, heart failure, drugs (NSAIDS, ACE-I, ARBS)

Removal of nephrotoxic drugs and hydration can lead to recovery.

Question 5

AKI can be post-renal. What does this mean and how is it caused and treated?

Answer 5

Outflow obstruction

This could be due to stones, prostatic hypertrophy & tumours

This will resolve once the kidney can be drained, by catheter or nephrostomy tube.

Question 6

Intrinsic AKI is due to….

Answer 6

acute interstitial nephritis

direct damage to the kidney - due to drugs or toxic processes within the body including immunological problems, rhabdomyolysis, prolonged uraemia from other causes of AKI.

Try to rectify the cause of the AKI.

Question 7

symptoms of AKI

Answer 7

unwell
oliguric - reduced urine flow
anuric - no urine flow
hypotensive - if dehydrated
hypertensive - if overloaded

Question 8

How is AKI prevented?

Answer 8

Maintaining hydration

Treat infections

Good nursing of vital signs, fluid input and output
avoidance of nephrotoxic drugs unless essential and then

Used only with careful monitoring.

Question 9

What should systolic BP be to maintain renal perfusion?

Answer 9

> 110mmHg

Question 10

if overloaded loop diuretics may be used

Answer 10

but if they don’t work then they need to be stopped as patient will become toxic. The kidney is temporarily incapable of producing fluid output.

Question 11

Management of AKI essentially covers three areas

Answer 11

1) Identification of cause and deal with it
2) Removal of nephrotoxic drugs
3) maintain fluid and pH homeostasis, management of biochemical derangements especially hyperkalaemia.

Question 12

ACE’s, ARB’s and NSAIDs effect the kidney how

Answer 12

they impair the perfusion of the kidney and should be withheld.

ACE/ARB will increase potassium even when pre-renal hypoerfusion is not the cause of the AKI.

Question 13

is eGFR/CrCL accurate in AKI?

Answer 13

No

Question 14

Can we give full dose ABx in AKI?

Answer 14

Yes - may be the infection causing the AKI

Question 15

Does AKI have a high or low mortality rate?

Answer 15

High

Question 16

what is the prevalence of the causes of AKI?

Answer 16

80% pre renal and tubular necrosis
10% intrinsic
10% post renal

Question 17

post renal causes of AKI include

Answer 17

BPH
prostate cancer
retroperitoneal fibrosis
renal calculi

Question 18

intrinsic causes of AKI include (damage to the functional tissues of the kidney)

Answer 18

• acute interstitial nephritis (cause by hypersensitivity reaction and often drug induced)
• myeloma
• immunological renal disease including vasculitis and glomerulonephritis
• rhabdomyolysis

Question 19

signs of hypovolaemia include

Answer 19

reduced jugular venous pressure
reduced central venous pressure
reduced BP
increased HR

Question 20

sings of hypervolaemia include

Answer 20

raised jugular venous pressure
raised central venous pressure
raised HR
increased of decreased BP
reduced oxygen saturation
increased RR

Question 21

Risk factors for AKI include

Answer 21

Age

Long-term disease (CKD, DM, HF, Liver, vascular)

Surgical procedures

Medication

Question 22

Points about NSAIDS

Answer 22

• They inhibit prostaglandin synthesis
• They cause proteinuria
• They should be avoided in patients with AKI
• They can cause interstitial nephritis

Question 23

Causes of intrinsic AKI include

Answer 23

myeloma
rhabdomyolysis
vasculitis

Question 24

Medicines known to cause acute tubular necrosis include

Answer 24

calcineurin inhibitors
ciprofloxacin
aciclovir

Question 25

Pre-renal AKI

Answer 25

• responds to fluid administration
• can be cause by laxative abuse
• can be differentiated from intrinsic causes of AKI through urinalysis

Question 26

Points about loop diuretics

Answer 26

• gut oedema can reduce their absorption
• if high doses do not induce diuresis in fluid-overloaded patients they should be stopped
• they can cause interstitial nephritis

Question 27

CANDA stands for

Answer 27

Contrast media

ARB/ACE

NSAIDS

Diuretics

Aminoglycosides

Question 28

CRCL is reduced in

• pregnancy
• AKI
• cachetic patient (muscle waste)

Answer 28

True