Assessment of renal function Flashcards
What is AKI?
Acute Kidney Injury (AKI)
When things go wrong acutely the kidneys suddenly cannot function and therefore efficient excretion and homeostasis cannot be achieved
The animal will present as very sick (large painful bladder and kidneys) with lethargy, possibly anorexia, vomiting and anuria.
What is chronic kidney disease?
Prolonged (>2 months) loss of renal tissue
Irreversible
In chronic kidney disease the animal Cant concentrate urine appropriately or excrete nitrogenous waste, this Leads to dehydration, azotaemia/ uraemia and electrolyte imbalance
Why do we use creatinine as a measure of GFR?
Creatinine is freely filtered by the glomerulus so its clearance is therefore a close approximation of GFR and production from the muscle is constant
Glomerular function can also be assessed by the presence of:
Urea - Horses and ruminants are less reliable as there is microbial NH3 production
Insulin: Injected and excretion directly proportional to that of water and salts
A decrease in the number of functional nephrons has what effect on the Urea and creatinine levels
They increase
High BUN/Cr implies 70-75% nephron loss
What is BUN?
Blood urea nitrogen
An increase of BUN:Cr ratio means…
Decreased blood flow to the nephrons or fewer functioning nephrons
What are casts and are they normal in urine?
Should be none in urine
Protein/cell collections moulded in lumen of tubules
What do casts in the urine suggest?
Suggests tubule disease/damage
What are the types of cast and what do they suggest?
Cellular (rbc/wbc/epithelial cells) - Disease process is in tubules
Granular (fine/coarse)
Degenerate cellular casts – implies longer stasis, Precipitated protein and degenerate epithelial cells
Waxy – end product of degeneration: Implies long period of stasis
Hyaline casts are formed from Tamm-Horsfall mucoprotein and are caused by dehydration
