DM3 Pt4-1 Acute Kidney Injury (AKI)

Question 1

What are the two most important causes of Acute Kidney Injury (AKI)?

Answer 1

Toxins and ischaemia (lack of blood/oxygen supply)

Question 2

How much cardiac output does the kidney receive?

Answer 2

About 20% of cardiac output

Question 3

Name a few blood-borne toxins that can cause AKI in cats.

Answer 3

Aminoglycoside antibiotics, antifreeze, NSAIDs, lilies

Question 4

What can cause ischaemia in AKI?

Answer 4

Severe hypotension (mean blood pressure < 70mmHg) or hypoxia

Question 5

Which kidney structures are most affected by toxins or ischaemia?

Answer 5

The proximal convoluted tubule and thick ascending limb of the Loop of Henle

Question 6

What are the three phases of AKI?

Answer 6

1. Initiation 2. Maintenance 3. Recovery

Question 7

What characterizes the initiation phase of AKI?

Answer 7

Appropriate treatment may reverse the renal failure.

Question 8

What happens during the maintenance phase of AKI?

Answer 8

Tubular damage and disruption of nephron function.

Question 9

What occurs during the recovery phase of AKI?

Answer 9

Damaged nephrons are not replaced, but remaining nephrons may hypertrophy and compensate.

Question 10

What are some clinical signs of AKI in cats?

Answer 10

Lethargy, inappetence, vomiting, diarrhea, dehydration, and uraemic breath.

Question 11

What must be demonstrated to confirm a diagnosis of AKI?

Answer 11

Azotaemia on blood tests with suboptimally concentrated urine.

Question 12

Why might polyuria occur in animals with AKI?

Answer 12

Disruption of urinary concentrating mechanisms or recovery phase of AKI.

Question 13

Which animals are “at-risk” for iatrogenic renal injury?

Answer 13

Animals with hypovolaemic or vasodilatory shock, trauma, sepsis, pyometra, or pre-existing renal insufficiency.

Question 14

What should be ensured during anesthesia or after trauma in “at-risk” animals?

Answer 14

Adequate hydration, blood pressure, and urine production.

Question 15

What should be avoided in “at-risk” animals to prevent iatrogenic renal injury?

Answer 15

Avoid nephrotoxic drugs like NSAIDs. Appropriate use of NSAIDs is safe in cats.

Question 16

Why is AKI considered a medical emergency?

Answer 16

AKI requires immediate discontinuation of nephrotoxic drugs, treatment of any pre/post-renal abnormalities, and management of electrolyte or acid-base imbalances.

Question 17

What is the first step in treating AKI?

Answer 17

Start intravenous fluid therapy with 0.9% NaCl, aiming to rehydrate the animal within 6 hours.

Question 18

What should be monitored to prevent over-hydration in AKI?

Answer 18

Clinical signs (skin tenting, mucous membranes), total protein, PCV, arterial blood pressure, central venous pressure, and urine production.

Question 19

Why is monitoring potassium concentrations important in AKI?

Answer 19

Potassium excretion is impaired, leading to hyperkalaemia, which can cause cardiac dysfunction. Polyuria during recovery may lead to potassium depletion.

Question 20

What diuretics may be required for AKI patients?

Answer 20

Furosemide or mannitol, especially in animals that remain oliguric despite adequate blood pressure/hydration.

Question 21

When might sodium bicarbonate be required in AKI?

Answer 21

To treat severe acidosis.

Question 22

What should be done to manage nutrition in cats with AKI?

Answer 22

Encourage eating as soon as possible, ideally palatable, easily digestible foods with good quality protein.

Question 23

What drug may be needed to treat persistent vomiting in AKI?

Answer 23

Anti-emetics like metoclopramide.

Question 24

How should prolonged hyperphosphataemia in AKI be treated?

Answer 24

With dietary phosphate binders.