Renal failure Flashcards
Describe incidence acute kidney injury
- Rare
- All species
- Poor prognosis
- 3 levels
What are the 3 levels at which acute kidney injury can occur?
- Pre-renal
- Renal/intrinsic (worst prognosis)
- Post-renal
What may cause pre-renal acute kidney injury?
- Loss of blood, fall in perfusion
- e.g. haemorrhage
- Need to support underlying cause (hypovolaemia)
What causes intrinsic AKI?
- Many nephrotoxins
- Lillies, anti-freeze, NSAIDs
What can cause post-renal AKI?
- Blockage leading to back flow
- Slows GFR and build up urea
- e.g. renal stones
What are the physiological effects of AKI?
- Loss of efficient excretion and homeostasis
- Uraemia, hyperkalaemia and acidosis
What are the clinical findings in AKI?
- Rapid and progressive
- Very sick (high uraemia)
- Large painful bladder/kidneys
- Lethargy
- Depression
- Anorexia
- Vomiting
- Dehydration
- No urine (anuria) as no GFR
Describe chronic kidney disease
- Common
- Cats > dogs > horses
- Prolonged (>2 months) loss of renal tissue
- Progress - chronic interstitial nephritis
- Irreversible
- Prognosis variable
When are clinical signs apparent in chronic kidney disease?
- Loss of 70% of renal tissue
- USG can decrease early on
What are the clinical signs of chronic kidney disease?
- Weight loss
- Poor body condition
- Loss of muscle mass
- Increased water intake
- Decreased appetite
- Ventroflexion (cats)
- PU/PD
- GI signs
- Small knobbly kidneys
- Non-regenerative anaemia
- Blindness
- Uraemia, azoaemia, dehydration
Why does polydipsia occur in chronic kidney disease?
- Hyperfiltration in remaining nephrons
- Higher GFR, reduced reabsorption, increased loss of water
- More urine produced
- Need to replace loss by drinking more
Why does ventroflexion occur in chronic kidney disease?
- Fall in potassium
- Cats due to lack of nuchal ligament
- Fatigue as need potassium for muscle contraction
Why do gastrointestinal signs occur with chronic kidney disease?
- High urea in blood irritates stomach lining
- Vomiting and nausea occur
Why does non-regenerative anaemia occur with chronic kidney disease?
- EPO produced in kidneys, loss of kidney leads to loss of EPo
- EPO trigger maturation of RBCs so will get anaemia with kidney disease
Why can blindness occur with chronic kidney disease?
Increased blood pressure can lead to burst blood vessels in back of retina
What is the difference between acute and chronic kidney disease?
- Acute very quick, chronic gradual
- In both signs shown renal insufficiency occurs (33% of kidney left)
- In chronic likely to be skinny due to loss of protein, rise in blood pressure can lead to blood clots in eye
What are the features of a renal diet?
- Reduced phosphate
- High quality protein
- Fat soluble vitamins
- Low sodium
- Potassium
What treatment options are available for kidney disease?
- Calcium channel blockers, vasodilation of efferent arterioles, reduces filtration pressure
- Decrease GFR (fortekor), in order to retain protein
- Potassium supplementation
- Correct acidosis potentially (bicarbonate solution)
- Synthetic EPO to correct anaemia
List some clinical pathological features of renal dysfunction
- PU/PD
- Weight loss
- Hypertension
- Vomiting, loss of appetite
- Blindness
- Anaemia
Why does hypertension occur with chronic kidney disease?
- Released renin due to perceived poor perfusion in kidney (damaged areas not perfused)
- Release of renin, activation of RAAS
- Increase in blood pressure
- Further damage to remaining nephrons
