Urinary Flashcards
what is acute renal failure?
abrupt and sustained decrease in GFR resulting in azotaemia and fluid/electrolyte disturbance
is acute renal failure reversible?
yes, in the early stages
what is the main cause of post-renal azotaemia in horses?
neonates with bladder rupture
what pre-renal factors can lead to acute renal azotaemia?
hypovolaemia
volume redistribution (effusions…)
decreased cardiac output
altered vascular resistance (sepsis…)
what is the main renal factor that causes acute renal failure?
acute tubular necrosis secondary to ischaemia or nephrotoxin exposure
what are some possible nephrotoxins?
antibiotics - ahminoglycosides, tetracyclines…
endogenous - haemoglobin, myoglobin…
others - NSAIDs, heavy metals…
what commonly exacerbates the effect of nephrotoxic drugs?
dehydration
what should be monitored in horses being given potentially nephrotoxic drugs?
serum creatinine
what is the most nephrotoxic aminoglycoside?
neomycin
what part of the kidney are aminoglycosides toxic to?
proximal tubular epithelial cells (reabsorbed and accumulates in these which interferes with function)
what can possible be done to reduce the nephrotoxicity of aminoglycosides before they are administered?
treat with calcium
what causes NSAIDs to be nephrotoxic?
medullary crest and papillary necrosis
sloughing of tubular epithelial cells
how can acute renal failure be differentiated from pre-renal azotaemia?
pre-renal azotaemia should be rapidly reversible with fluid therapy
what electrolyte changes are seen with acute renal failure?
hyponatraemia
hypochloraemia
hypocalcaemia
hyperphosphataemia
when is hyperkalaemia seen with acute renal failure?
if the horse is oliguric
what should be done to treat acute renal failure?
IV fluids
stop nephrotoxic drugs
what fluids should be given to horses with acute renal failure?
hartmanns (maintaining twice maintenance if polyuric)
when is diuretic therapy needed for acute renal failure treatment?
if the animal is oliguric
what diuretic therapy is given to horses with acute renal failure and oliguria?
furosemide and dopamine (synergistic)
why is dopamine given as part of diuretic therapy for horses with acute renal failure and oliguria?
potent renal vasodilator acting specifically on arteriole receptors
why is chronic renal failure rare in horses?
massive reserve capacity
what are the clinical signs of chronic renal failure?
weight loss, lethargy, poor coat, PUPD
oral ulceration, gastroenteritis, halitosis
ventral oedema
how is chronic renal disease diagnosed?
persistent isosthenuria with azotaemia and clinical signs
how is chronic renal disease treated?
palliative
always need water/salt available
lower protein nutrition
decrease calcium if high in diet