Kidney - Clinical Path.

Front 1

hormones are responsible for re-absorption in the kidney. which hormones cause reabsorption and of what

Back 1

2 act on the distal convoluted tubule....

PTH- calcium reabsorption.
Aldosterone- Na reabsorption and K secretion

ADH act on the collecting duct

Front 2

how is urine concentration measured and why might this be an inaccurate reading

Back 2

using a refractometer to indirectly measure the USG.

glucose and protein can provide a false high reading

Front 3

define hypo-sthen-uria, Iso-sthen-uria and hyper-sthen-uria and give the ranges for hyop, iso and adequate for dog, cat, horse and cow

Back 3

hypo-sthen-uria- when the osmolarity of the urine is less than that of the plasma

iso-sthen-uria- when the osmolarity of the urine is = to that of the plasma

hyper-sthen-uria- when the osmolarity of the urine is higher than that of the plasma


all hypo- <1.007
all iso- 1.007-1.012
adequate for...

dog- >1.030
cat->1.035
horse and cow - >1.025

Front 4

what is the name of the condition in which there is a lack of ADH or the kidneys don't respond to ADH

Back 4

diabetes insipidus

Front 5

what is the method used to measure the GFR and what level of damage is needed to seen a change in creatinine. what else might cause this parameter to rise or fall.

Back 5

the rate a substance is cleared from the plasma ( expensive and hard to do) eg creatinine or urea as it is not reabsorbed and is produced at at relatively constant rate by muscle.

requires a 3/4 loss of functioning nephrons.

good in rum and horses as non renal factors are not as significant. creatinine may rise due to dehydration, high muscle mass- greyhounds. it may be low if muscle mass is very low eg is cachexia.

Front 6

what two endogenous products can be used to measure GFR and why would you want to measure GFR

Back 6

creatinine and urea. GFR is the best predictor of renal function.

Front 7

in which species would you not want to use urea or creatinine to measure GFR

Back 7

urea- horses ( some excreation in the GI ) and ruminant ( recycled in rumen to make AAs with bacteria which can break down urea)

creatinine is fine in all species but grayhounds will have higher values due to their high muscle mass

Front 8

what might cause a non renal increase or decrease in urea

Back 8

increase- dehydration/high protein /GI haemorage/starvation

decreased- liver insuficiency/ low protein diet/ urea cycle problems

Front 9

define azotaemia and how it is classed and uremia

Back 9

azotaemia- an increase in non protein nitrogenous products in the blood ( eg urea and or creatinine ) classed as renal/pre/post renal.

uremia- clinical signs of azotaemia ( vommiting / diarrhoea/ ulcers/ ammonia breath smell

Front 10

how do you differentiate between pre renal/ post renal and renal azotemia.

Back 10

USG

Front 11

what is prerenal azotaemia caused by and what might USG be

Back 11

extra renal causes which decrease renal blood flow and GFR. (eg dehydration , scock, decreased CO) the kidneys are stimulated to conserve water so the urine is concentrated- so USG appears 'adequate'.

Front 12

describe renal azotaemia and what USG will it produce

Back 12

any renal disease which causes a major decrease in GFR ( around 75% of nephrons would have to be lost)

isosthenuria - 1.007-1.012

Front 13

describe post renal azotemia and what USG might be

Back 13

caused by reduced renal blood flow due to increased pressure within the renal collecting system- UT blockage or leakage into body cavity.

variable USG.

Front 14

what amount of renal functional mass must be lost before the ability to concentrate urine is lost

Back 14

2/3

Front 15

how is total calcium affected in azotemic patients

Back 15

variable.

dog/cat/cow- in chronic renal disease it is usually low ( as less calcium is reabsorbed and there is less vit D)

horse- often high ( a lot of calcium is usually excreated via the kidenys)

Front 16

how is total phosphorus affected in azotemic patients

Back 16

in dogs and cats there is decreased renal clearence of phosphorus so increased levels in the blood.

cattle and horses - may or may not see in horses as they have other ways of excreation

Front 17

how is total potassium affected in azotemic patients

Back 17

hyperkalemia ( main rout of excretion) seen if there is anuric or oliguric renal disease except cattle who are more likely to have hypokalaemia.

Front 18

what might be the consequence of renal failure in a dog or cat

Back 18

secondary renal hyperparathyroidism- leads to tissue mineralisation and fibrous osteodystrophy ( rubber jaw). hyperplasia of the parathyroid may develope

renal failure causes hypocalcaemia dog/cat/cow- in chronic renal disease it is usually low ( as less calcium is reabsorbed and there is less vit D) and hyperphosphatemia (in dogs and cats there is decreased renal clearence of phosphorus so increased levels in the blood.)

PTH will reabsorb Ca from the bone and kidney and cause loss of phorphorus via the kidney

Front 19

does the size of the azotaemia tell you if it can be reversed.

Back 19

no

Front 20

how do you tell if renal disease is chronic

Back 20

duration of clinical signs. may see Azotaemia with isosthenuria and non regenerative anaemia (production of erythropoietin)

Front 21

how might you collect urine for testing and give some adv/dis

Back 21

cystocentesis- best in dogs and cats. possible risk of seeding neoplastic cells.

catheter- contamination

voided- contamination

Front 22

list the causes of aciduria and alkalinuria

Back 22

Aciduria
–Carnivores (protein breakdown)
–Metabolic or respiratory acidosis
–Paradoxical aciduria
Alkalinuria
–Herbivores
–Urease-containing bacteria
–Prolonged storage at room temp
–Metabolic/respiratory alkalosis

Front 23

how much protein is normally in the urine. and what elses should always be considered when measuring it.

Back 23

little to none.
always consider USG.

also there are many false positives eg alkaline urine or increased contact time.

also UPC ratio is a more accurate way of measuring the protein.

Front 24

what is a normal-questionable and abnormal UPC ratio and what else must be considered

Back 24

normal- <0.5
questionable-0.5-1
abnormal->1
>5 indicates a glomerular component

consider sediment contents. active sediments ( eg haemorage or inflammation ) will make p:c ratio unreliable

Front 25

list some prerenal , renal and post renal causes of proteinuria

Back 25

Prerenal
–Fever, strenuous exercise
–Colostrum
–Hgb, Mgb, Bence-Jones proteinuria
•Renal
–Glomerular disease
–Tubular disease
•Postrenal
–Hemorrhage
–Inflammation
•If occurs in kidneys, then not really postrenal

Front 26

how do you differentiate between intact RBCs ( hematuria ) and Hb or Mb and what else should you consider.

Back 26

RBCs- red colour will clear on centrifugation and plasma will be clear. ( should consider that very dilute urine might cause lysis of RBCs as well as a low ph)

Hb or Mb- red colour does not clear on centrifugation and plasma will be red if Hb

Front 27

what might cause a false positive or negative for urine glucose

Back 27

False positive:
•Hydrogen peroxide
•Bleach
•Penicillins
•False negative:
•Prolonged dipstick storage
•Vitamin C
•Tetracycline
•Urinary tract infection (bacteria utilize glucose)

Front 28

what else should you look at if investigating glucosuria

Back 28

blood glucose.

Front 29

what does Glucosuria with persistent hyperglycemia tell you

Back 29

Diabetes mellitus until proven otherwise

Front 30

what causes ketones in urine

Back 30

Ketosis is due to negative energy balance
–Diabetes mellitus (diabetic ketoacidosis)
–Bovine ketosis
–Starvation
–Late pregnancy/early lactation