Renal function/integrity (Yr 4)

Question 1

what are the functions of the kidney?

Answer 1

excretion of waste
control of body fluid balance (pressure, electrolytes, acid-base)
production of hormones (erythropoietin, calcitriol, renin)

Question 2

what is calcitriol?

Answer 2

active form of vitamin D

Question 3

what is excreted by the nephron?

Answer 3

urea
creatinine
potassium
hydrogen
phosphate
ketones/lactate

Question 4

what is conserved by the nephrons?

Answer 4

water
amino acids/proteins
glucose
bicarbonate
sodium/chloride
magnesium/calcium

Question 5

what are the three parts of a urinalysis?

Answer 5

USG
dipstick
sediment

Question 6

what needs to be measured to determine if the kidneys are working effectively?

Answer 6

glomerular filtration rate

Question 7

how can glomerular filtration rate be measured accurately in practice?

Answer 7

exogenous creatinine clearance (this is rarely done)

Question 8

how can GFR be indirectly measured in practice?

Answer 8

urea or creatinine

Question 9

how will urea and creatinine change if GFR decreases?

Answer 9

will both increase as they aren’t being filtered

Question 10

how are urea and creatinine differed?

Answer 10

urea is made in the liver from ammonia and can be reabsorbed
creatinine is constantly produced by muscle and not reabsorbed

Question 11

where is creatinine made?

Answer 11

muscles (constantly produced)

Question 12

is creatinine or urea a better marker for GFR?

Answer 12

creatinine as it isn’t reabsorbed by the kidney and is less effected by other processes

Question 13

what can cause increased urea?

Answer 13

decreased GFR
upper GI haemorrhages
recent meals
catabolism (fever, corticosteroids…)

Question 14

what can cause decreased urea?

Answer 14

severe liver disease or portosystemic shunts
low protein diet
aggressive fluid therapy
PUPD
young animals

Question 15

what can cause increased creatinine?

Answer 15

decreased GFR
high muscle mass
high dietary protein

Question 16

what can cause decreased creatinine?

Answer 16

reduced muscle mass

Question 17

what is the name for increase urea and creatinine in blood?

Answer 17

azotaemia

Question 18

what are the three causes of azotaemia?

Answer 18

pre-renal
renal
post-renal

Question 19

what causes pre-renal azotaemia?

Answer 19

dehydration or decreased cardiac output

Question 20

how can you tell azotaemia is pre-renal?

Answer 20

clinical evidence of dehydration/hypovolaemia
if USG is normal (adequately concentrated)
they should respond to fluid therapy

Question 21

what is adequate concentration for USG?

Answer 21

dogs - >1.030
cats - >1.035

Question 22

how can you diagnose if an azotaemia is renal?

Answer 22

variable USG…
can be isosthenuric (1.008-1.012)
USG inadequately concentrated (<1.030 in dogs, <1.035 in cats)

Question 23

how can post-renal azotaemia be diagnosed?

Answer 23

lack of urine output, full bladder (painful)
usually hyperkalaemic

Question 24

how much nephron function needs to be lost for renal azotaemia to present?

Answer 24

75%

Question 25

what is a possible test for GFR that increases when there is less nephron loss (40%) so can detect disease earlier?

Answer 25

SDMA (not perfect... puppies/kittens)

Question 26

what are the three main electrolyte changes associated with the kidney?

Answer 26

phosphorous potassium calcium

Question 27

what does hyperphosphataemia reflect in animals with high dietary phosphorous content?

Answer 27

decreased GFR

Question 28

what can cause increased potassium?

Answer 28

fluid compartment shift in acidosis decreased urinary output (anuria, oliguria, bladder rupture, obstruction)

Question 29

what can cause increased potassium?

Answer 29

increased urinary loss (CKD) decreased food intake or GI loss

Question 30

where is urea made?

Answer 30

liver

Question 31

what is USG a measure of?

Answer 31

solutes in urine

Question 32

what is the USG of plasma?

Answer 32

1.010

Question 33

what is adequately concentrated urine in dogs and cats?

Answer 33

dogs >1.030 cats >1.035

Question 34

when would a sub-optimally concentrated urine be a cause for concern?

Answer 34

if the animal is dehydrated

Question 35

if USG is hyposthenuric (lower than 1.010) are the kidneys functioning normally?

Answer 35

yes - nephrons have to be functioning otherwise they would be isothenuric

Question 36

what is needed to accurately quantify proteinuria?

Answer 36

protein to creatinine ratio (UPCR)

Question 37

what are the three things that should be checked when you have diagnosed a proteinuria?

Answer 37

location persistence magnitude

Question 38

where can proteinuria be located to?

Answer 38

pre-renal renal post-renal

Question 39

what can cause a pre-renal proteinuria?

Answer 39

fever systemic inflammation haemoglobinaemia myoglobinaemia

Question 40

what can cause a post-renal proteinuria?

Answer 40

UTI nephrolithiasis tumours of urinary tract

Question 41

is glucose a normal constituent of urine?

Answer 41

no (not normally present)

Question 42

what is ignored on a dipstick for urine?

Answer 42

nitrite leucocytes

Question 43

what are casts?

Answer 43

cylindrical moulds of tubules composed of mucoproteins (plus cells)

Question 44

where can you localise the problem to if there are casts in the urine?

Answer 44

the actual kidney (tubules)

Question 45

when should urine be assessed for crystals?

Answer 45

only in fresh urine (older samples can develop crystals)

Question 46

what are the common crystals seen in urine?

Answer 46

struvite urate phosphate calcium oxalate di/monohydrate ammonium biurate cystine

Question 47

what shape are struvite crystals?

Answer 47

coffin lid

Question 48

what substance makes struvite crystals?

Answer 48

magnesium ammonium phosphate

Question 49

what pH urine do struvite crystals form in?

Answer 49

alkaline

Question 50

what crystals are associated with ethylene glycol toxicosis?

Answer 50

calcium oxalate monohydrate