Lab 11- Kidney Function Flashcards
What is lab diagnosis of kidney func based off
Body weight
- increase –> oedema, ascites
- decrease –> chronic kidney disease
Body condition
General status/ behaviour
- depressed
Fur quality, skin turgor
- not nice hair
- decreased turgor
Shape of body
- swelling
Water
- normal
20-40 ml/kg body weight/day
Water
- max
80 ml/kgBW/day - dog,
40 ml/kgBW/day - cat
Water
- General dog
- Small dog
(30 ml/ kg bw): 1 l/day
3 dl/day (300 ml/day)
Water
- Cat
1 dl/day (100 ml/day)
Water
- Horse
20-30l/day
Water
- Cattle
20-40 l/day
Water
- sheep/goat
1-2 l/day
Water
- swine
3-8 l/day
Urine output
- dog
20-40 ml/kg body weight/day
Urine output
- ccat
10-20 ml/kg body weight/day
Urine output
- horse
5-15 l/day
Urine output
- cattle
20-40 l/day
Urine output
- sheep
1-2 l/day
Urine output
- Swine
3-8 l/day
What is diagnosis of kidney failure based off?
anamnesis, physical examination of the patient and laboratory examination of blood and urine
(urinary sediment, protein, sodium, potassium, calcium, inorganic phosphate and creatinine content of urine).
Azotaemia
accumulation of nitrogen containing protein breakdown products in the blood (for example: urea).
Ureamia
severe increase in the level of nitrogen containing protein breakdown products and toxins in the blood, leading to obvious clinical signs
Determination of Glomerular function
- Urea colour test
- Enzymatic Urea method
normal urea vol
8-10 mmol/l
Causes of increased blood urea concentration:
- pre renal factors
- increased Nitrogen intake
- Poor energy status in ru
Ru protein intake
- how it is catabolised
- into Nh3 and resynthesised by rumen micro organisms.
10% bypass proteins
Where is urea excreted from?
salivary gland, ruminal wall, kidney and
udder too.
Ru: urea conc milk
2-3 mmol/l
What does energy defiency in ru cause?
increased urea
concentration in blood and in milk, increased ketone concentration in blood, urine and milk;
and decreased glucose concentration in blood and increased total lipid concentration in the
blood.
What is urea an indicator of?
small intestinal bacterial overgrowth (SIBO) similarly to vitamin-B12
decrease (increased utilisation by bacteria) and folic acid increase (increased production by bacteria)
What does blood in the intestines cause?
typically increases urea concentration in the blood and it can cause significant diagnostic problems!
Haemolysis: what does it to do the urea conc
Increase in conc
What does an increased catabolism of the tissues own proteins cause?
energy deficiency (due to for example decreased carbohydrate intake),
widespread neoplastic processes,
high fever,
endogenous overproduction or iatrogenic overdose of catabolytic hormones (thyroxine, glucocorticoids))
What does a decreased blood perfusion of the kidneys cause?
shock,
hypotension,
dehydration,
cardiac failure,
hypoadrenocorticism (Addison’s disease),
thromboembolism or
strangulation of the renal artery.
Causes of decreased urea conc
Impaired liver function: decreased urea synthesis in the liver cells from NH3, leading to
increased NH3 level.
Haemodilution (hyperhydration)
decreased protein intake (starvation, anorexia)
How does creatinine produce energy in muscle
converts to creatin
this is bound to a phosphate group
when released provides energy
what is creatinine a good indicator of?
Glomerular function
- bc its filtered by the kidney and not reabsorbed
Determination of creatinine methods
Jaffe method
Enzymatic method
Creatinine
- Jaffe method
- what is the result highly influenced by?
Creatinine forms a yellow orange complex w picric acid on alkalytic pH
- haemolysis and jaundice
Creatinine
- normal value
50-200 umol/l
Creatinine
- what does its blood conc depend on?
meat content of diet
state of muscles
- muscle cell damage –> increase
- cachexia –> decrease
kidney
Creatinine
- When GFR decreases … creatinine ….
increases
Creatinine
Plasma urea (mmol/l) / plasma creatinine (µmol/l)
- normal value
0.1-0.06
Creatinine
Plasma urea (mmol/l) / plasma creatinine (µmol/l)
- what does it mean if it is more than 0.06?
pre renal kidney failure
decreased blood supply of kidney
post renal causes - ureter, urethra,
Creatinine
Plasma urea (mmol/l) / plasma creatinine (µmol/l)
- what does it mean if it is less than 0.06?
renal causes
Changes in plasma urea and creatinine conc NOT due to renal disease
- High urea, low or normal creatinine
High urea:
increased protein intake
gastrointestinal bleeding
fever (increased protein catabolism)
tetracycline, steroid treatment
haemolysis necrotic processes
hyperthyroidism (increased protein catabolism)
catabolic drugs (amphetamine)
Low, normal creatinine
cachexia
chronic muscle atrophy
Changes in plasma urea and creatinine conc NOT due to renal disease
- low or normal urea, high creatinine
Low, normal urea:
liver failure, portosystemic shunt
polyuria-polydypsia
low protein intake
anabolic steroids
High creatinine:
inflammation of muscles (myocarditis, rhabdomyolysis)
rhabdomyosarcoma
muscle trauma
increased meat intake
normal creatinine clearance in:
- dogs
- cats
2.4-5 (dog),
1.9-5 (cat)
What is proteinuria an essential indicator of?
glomerular dysfunction
proteinuria febrilis
higher protein concentration in urine despite normal renal function
