Acute Kidney Injury

Question 1

What is acute kidney injury?

Answer 1

sudden kidney failure meaning that blood volume and electrolytes cannot be managed properly and urea and nitrogenous waste are retained

Question 2

What 3 things classify acute kidney injury?

Answer 2

• anuria/oliguria (<0.5ml/kg/hr) for >8 hours
• rapid rise in plasma creatinine
• hypertension with fluid overload

Question 3

By how much does the creatinine have to increase to be worried about AKI?

Answer 3

1.5x age specific reference creatinine or previous baseline if known

Question 4

What are the 3 levels of the AKI warning score and what is it based on?

Answer 4

• AKI 1-3

- based on increasing creatinine levels on relation to the upper limit of reference interval

Question 5

AKI 1.

Answer 5

measured creatinine>1.5-2 times ULRI

Question 6

AKI 2.

Answer 6

measured creatinine 2-3 times ULRI

Question 7

AKI 3.

Answer 7

serum creatinine >3 times ULRI

Question 8

How is acute kidney injury managed?

Answer 8

• prevention!!
• Monitor: urine output, PEWS, BP, weight
• Maintain: good hydration
• Minimise: Drugs

Question 9

What are the 3 different ways be can split up thinking of causes of acute kidney injury?

Answer 9

• pre-renal
• intra-renal
• post-renal

Question 10

Generally speaking, what causes pre-renal AKI?

Answer 10

a perfusion problem e.g. volume depletion, hypotension, renal artery stenosis

Question 11

What are intra-renal causes of AKI?

Answer 11

• glomerular disease such as haemolytic uraemic syndrome*** and glomerulonephritis
• tubular injury e.g. acute tubular necrosis because of hypo perfusion or drugs
• interstitial nephritis as a result of NSAIDs, penicillin or diuretics

Question 12

What is haemolytic uralic syndrome?

Answer 12

• a condition caused by bacterial toxins from eating contaminated food
• results in acute haemolytic anaemia and thrombocytopenia

Question 13

What bacteria are normally involved in HUS?

Answer 13

• shiga toxin producing e.coli

- shigella species

Question 14

What toxin do the bacteria produce that causes the problems?

Answer 14

shiga toxin

Question 15

What is the pathophysiology behind HUS?

Answer 15

• the shiga-toxin binds to endothelial cells in the glomerular arteriole
• this results in clots forming with platelets to try to plug the gap
• RBCs get damaged travelling through the arterioles and so get removed from blood by spleen resulting in haemolytic anaemia
• platelets being used up for clots results in thrombocytopenia

Question 16

What are the presenting symptoms in HUS?

Answer 16

3 days after eating dodgy meat:
-diarrhoea
-abdominal pain
-fever
-vomiting
after a couple of days:
-bloody diarrhoea

Question 17

What is the triad of HUS?

Answer 17

• microangiopathic haemolytic anaemia
• thrombocytopenia
• acute renal failure

Question 18

How is HUS managed?

Answer 18

3Ms:
Monitor:
fluid balance, electrolytes, acidosis, hypertension and other organs

Maintain:
IV normal saline and fluid
renal replacement therapy

Minimise:
no antibiotics

Question 19

What can cause post-renal AKI?

Answer 19

obstruction

Question 20

What are long term consequences of AKI?

Answer 20

• blood pressure
• proteinuria monitoring
• evolution to CKD