DM3 Pt4-1 Acute Kidney Injury (AKI) Flashcards
What are the two most important causes of Acute Kidney Injury (AKI)?
Toxins and ischaemia (lack of blood/oxygen supply)
How much cardiac output does the kidney receive?
About 20% of cardiac output
Name a few blood-borne toxins that can cause AKI in cats.
Aminoglycoside antibiotics, antifreeze, NSAIDs, lilies
What can cause ischaemia in AKI?
Severe hypotension (mean blood pressure < 70mmHg) or hypoxia
Which kidney structures are most affected by toxins or ischaemia?
The proximal convoluted tubule and thick ascending limb of the Loop of Henle
What are the three phases of AKI?
- Initiation 2. Maintenance 3. Recovery
What characterizes the initiation phase of AKI?
Appropriate treatment may reverse the renal failure.
What happens during the maintenance phase of AKI?
Tubular damage and disruption of nephron function.
What occurs during the recovery phase of AKI?
Damaged nephrons are not replaced, but remaining nephrons may hypertrophy and compensate.
What are some clinical signs of AKI in cats?
Lethargy, inappetence, vomiting, diarrhea, dehydration, and uraemic breath.
What must be demonstrated to confirm a diagnosis of AKI?
Azotaemia on blood tests with suboptimally concentrated urine.
Why might polyuria occur in animals with AKI?
Disruption of urinary concentrating mechanisms or recovery phase of AKI.
Which animals are “at-risk” for iatrogenic renal injury?
Animals with hypovolaemic or vasodilatory shock, trauma, sepsis, pyometra, or pre-existing renal insufficiency.
What should be ensured during anesthesia or after trauma in “at-risk” animals?
Adequate hydration, blood pressure, and urine production.
What should be avoided in “at-risk” animals to prevent iatrogenic renal injury?
Avoid nephrotoxic drugs like NSAIDs. Appropriate use of NSAIDs is safe in cats.
Why is AKI considered a medical emergency?
AKI requires immediate discontinuation of nephrotoxic drugs, treatment of any pre/post-renal abnormalities, and management of electrolyte or acid-base imbalances.
What is the first step in treating AKI?
Start intravenous fluid therapy with 0.9% NaCl, aiming to rehydrate the animal within 6 hours.
What should be monitored to prevent over-hydration in AKI?
Clinical signs (skin tenting, mucous membranes), total protein, PCV, arterial blood pressure, central venous pressure, and urine production.
Why is monitoring potassium concentrations important in AKI?
Potassium excretion is impaired, leading to hyperkalaemia, which can cause cardiac dysfunction. Polyuria during recovery may lead to potassium depletion.
What diuretics may be required for AKI patients?
Furosemide or mannitol, especially in animals that remain oliguric despite adequate blood pressure/hydration.
When might sodium bicarbonate be required in AKI?
To treat severe acidosis.
What should be done to manage nutrition in cats with AKI?
Encourage eating as soon as possible, ideally palatable, easily digestible foods with good quality protein.
What drug may be needed to treat persistent vomiting in AKI?
Anti-emetics like metoclopramide.
How should prolonged hyperphosphataemia in AKI be treated?
With dietary phosphate binders.
