Acute kidney injury

Question 1

Define AKI?

Answer 1

reduction in kidney function in under 48hrs of: absolute increase in serum creatinine by >26.4 OR
increase in serum creatinine by >50% OR
reduction in urine output

Question 2

What must sometimes be done for stage 3 AKI?

Answer 2

referral to dialysis

Question 3

What are the risk factors for AKI?

Answer 3

older age
CKD
diabetes
cardiac failure
liver disease
peripheral vascular disease 
previous AKI 
hypotension
hypovoleamia

Question 4

What can cause pre renal AKI?

Answer 4

hypovoleamia
hypotension
renal hypoperfusion

Question 5

What is the presentation of pre renal AKI?

Answer 5

volume depletion leading to oliguria <0.5mls and an increase in creatinine

Question 6

How do ACEis cause a fall in GFR?

Answer 6

cause efferent arteriolar vasodilation

decreased renal perfusion

Question 7

What does untreated pre renal AKI lead to?

Answer 7

acute tubular necrosis

Question 8

What is acute tubular necrosis?

Answer 8

one of the most commonest causes of AKI in hospital
death of the tubular epithelial cells due to a cmobination of factors leading to decreased renal perfusion - rhabdomyolysis, drug toxicity, sepsis and severe dehydration

Question 9

How is pre renal AKI treated?

Answer 9

FLUID
crystalloid - 0.9% NaCl or gelofusin
give bolus

Question 10

What is renal AKI?

Answer 10

diseases causing inflammation or damage to the cells causing AKI

Question 11

What causes renal AKI?

Answer 11

vasculitis
glomerulonephritis
interstitial nephritis due to drugs and infection
tubular injury - rhabdomyolysis, gentamicin, ischaemia, contrast

Question 12

What are the signs of renal AKI?

Answer 12

fluid overload - oedema, effusions
uremia - itch
pericarditis
oliguria
anorexia
weight loss
nausea and vomiting
SOB

Question 13

What can a sore throat lead to?

Answer 13

strep glomerulonephritis

Question 14

What can both vasculitis and lupus lead to?

Answer 14

rash and joint pain

Question 15

What investigations should be done for AKI?

Answer 15

U&Es
FBC and coagulation screen - sepsis has abnormal clotting
urinalysis - haematoproteinuria
USS - one kidney bigger than the other (renal artery stenosis)
immunology - ANA, ANCA and GBM
protein electrophoresis

Question 16

How is renal AKI treated?

Answer 16

good perfusion pressrure - FLUIDS
stop nephrotoxics
dialysis is remains anuric and ureamia

Question 17

What are the complications of AKI?

Answer 17

hyperkalaemia
fluid overload
severe acidosis (pH <7.15)
uraemic pericardial effusion
severe uraemia >40

Question 18

What causes post renal AKI?

Answer 18

obstruction of renal flow causing back pressure - hydronephrosis
and therefore loss of the ability of the urine to become concentrated

Question 19

How can post renal AKI be treated?

Answer 19

relieve obstruction

put in a catheter

Question 20

What K level signals hyperkalaemia?

Answer 20

> 5.5

Question 21

What K level signals life threatening hyperkalaemia?

Answer 21

> 6.5

Question 22

What arrythmias does hyperkalaemia cause?

Answer 22

ventricular fibrillation
ventricular tachycardia
bradycardia

Question 23

What are the investigations for hyperkalaemia?

Answer 23

ECG

muscle weakness

Question 24

What are the treatments for hyperakalaemia?

Answer 24

10mls 10% calcium gluconate - normalises ECG and protects myocardium
Insulin 10 units actrapid 
50mls 50% dextrose - 30 mins
Salbutamol nebs - 90mins 
sodium bicarb if acidotic

Question 25

What is the role of giving insulin, dextrose and salbutamol?

Answer 25

helps the K go back into the cells

Question 26

What urgent signs indicate the need for dialysis?

Answer 26

hyperkalaemia > 7 or >6.5 - unresponsive to medical therapy
severe acidosis pH <7.15
fluid overload
urea >40 and pericardial rub/effusion

Question 27

What is the mortality rate of AKI?

Answer 27

10-30%

Question 28

What is the mortality rate of AKI with one other organ dysfunction?

Answer 28

30-50%

Question 29

What is the mortality rate of AKI with multiple organ dysfunction?

Answer 29

70-90%