Urinary medicine (Yr4) Flashcards
what causes pre-renal acute renal failure?
haemodynamic cause…
hypovolaemia, volume redistribution (effusions), decreased cardiac output, altered vascular resistance (endotoxaemia)
what cause post-renal acute renal failure?
uncommon… only really seen with neonates that rupture there bladder as blockages are uncommon
what are the renal causes of acute renal failure?
ischaemia or nephrotoxin exposure (less commonly glomerulonephritis)
what are some nephrotoxic substances?
antibiotics - aminoglycosides, tetracyclines
endogenous substances - haemoglobin, myoglobin
NSAIDs, heavy metals…
what should be monitored in horses on nephrotoxic drugs?
serum creatinine
what is the most nephrotoxic aminoglycoside?
neomycin
where do aminoglycosides accumulate?
proximal tubular cells (they are freely filtered at the glomerulus then reabsorbed by proximal tubular cells)
why are aminoglycosides (such as gentamicin) only given once daily?
reabsorption in the kidneys is time rather than dose dependant, so less toxic to give one large dose
what can you pre-treat horses with before giving gentamicin (aminoglycosides) to reduce the nephrotoxicity?
calcium
what will be a significant finding on urinalysis if there is pre-renal azotaemia?
maximally concentrated urine (>1.035)
how is acute renal failure treated?
IV fluids (Hartmans)
diuretics (furosemide)
stop nephrotoxic drugs
what fluid rate would you put a horse with acute renal failure on?
twice maintenance (60ml/kg/hr)
what diuretics can be used for treating acute renal failure?
furosemide
dopamine
what are the main causes of chronic renal failure?
glomerular disease
interstitial nephritis (from tubular necrosis)
renal neoplasia
amyloidosis
what clinical signs can be seen with chronic renal failure?
chronic weight loss
lethargy, PUPD, poor coat, poor performance
halitosis, oral ulceration
(possible ventral oedema but this is inconsistent)
how is chronic renal failure diagnosed?
persistent isosthenuria (1.008-1.014)
mild anaemia and hypoalbuminaemia
electrolyte abnormalities (hypercalcaemia, hyponatraemia…)
how can chronic renal failure be treated?
one;y palliative…
ensure water and salt available
lower protein (manage BUN)
decrease calcium
what is a good prognostic indicator for chronic renal failure?
creatinine (higher creatinine indicates a shorter survival time)
what is polyuria defined as?
urine output exceeding 50ml/kg/day
what is polydipsia defined as?
fluid intake exceeding 100ml/kg.day