Kidney disease testing and treatment Flashcards
(39 cards)
What is azotaemia?
Increased concentration of nitrogenous waste products in the blood
What is uraemia?
The clinical syndrome that results from loss of kidney function.
Define an acute kidney injury?
Aa rapid loss of kidney function. Reduced kidney function results in abnormal GFR, tubular function and urine production and therefore a sudden inability to maintain fluid, acid base, and electrolyte balance.
Define a chronic kidney disease
- Is present when there are structural or functional abnormalities of one or both kidneys that have been there for 3 months or longer.
- Typically there is reduced GFR and a reduced number of functioning nephrons
- An irreversible, slowly progressive disease
What is the best way to assess kidney function?
Glomerular filtration rate
What is the most accurate measurement of kidney function?
Plasma creatinine conc
What is meant by ‘clearance of drugs’?
Clearance of a solute (X) is the rate at which that X disappears from the body by excretion and/or metabolism
Total body clearance will be the … + … + …?
Renal clearance
Hepatic clearance
Lung clearance
How are we able to calculate GFR?
Using renal clearance of a substance that is not metabolised elsewhere in the body, it is not reabsorbed or secreted by the renal tubule
What factors make a good filtration marker?
- Not metabolised elsewhere in the body
- Freely filtered in glomerular capillaries
- Not reabsorbed or secreted anywhere in the kidney
- Exogenous
Give 2 examples of exogenous filtration markers of GFR
- Inulin (gold standard)
- Iohexol
The steady breakdown of creatine phosphate in skeletal muscle results in?
Creatinine
Where does reabsorption of urea occur and why?
Partially fat soluble so in the PCT
What is needed to prevent excessively high conc of urea in the blood?
Continuous high filtration rate
What is rate of urea production related to?
- Dietary protein intake
- Rate of endogenous catabolism of proteins (fever, starvation, vigorous exercise, recent GCC, burns, sepsis)
- GI haemorrhage
- Dehydration
What factors may reduce urea production?
- Anabolic steroids
- Liver failure
- Protein restricted diet
Why is creatinine a better indicator of GFR than urea?
Can lose up to 75% K function before GFR becomes abnormal
What is prerenal azotaemia?
- Reduced blood supply to the kidney absence of kidney disease. e.g. Cardiac disease, Hypovolaemic shock
- Pathology occurring upstream of kidney
- Animal IS able to concentrate urine
- In a case of prerenal azotaemia you are most likely to see an increase in urine specific gravity
Why is urine retained in post renal azotaemia?
- Because of metabolic acidosis and high potassium
- Blockage of urine flow below the kidneys
Would you expect hypovolaemic animals to have LOW urine SG or HIGH urine SG?
Animals with hypovolaemia (low blood volume) should be conserving volume i.e. concentrating filtrate & have a relatively high USG
What are the clinical signs of Chronic renal failure?
- Anorexia & weight loss
- Poor appetite (azotaemia)
- Dullness, lethargy, sleeping more
- PUPD (primary PU)
- Dehydration
- Vomiting (azotaemia)
- Constipation (dehydration and anorexia)
- Poor hair coat
- Neurological signs
Why does PUPD occur in kidney disease?
- Increased filter load per nephron
- Disruption of normal countercurrent system
- Impaired response to ADH
Why can hypertension be a sign of kidney disease?
- May involve sodium and fluid retention and activation of the RAAS
Why can neurological signs occur in azotaemia?
- Hypertension can also cause neurological signs.
- Hypokalaemia can lead to polymyopathy and weakness
