Kidney Dysfunction

Question 1

GFR vs body size in dogs

Answer 1

small dogs = high GFR and low creatinine

large dogs = low GFR and high creatinine

Question 2

stages of kidney dysfunction

Answer 2

normal <–> intrinsic injury –> structural damage –> kidney failure

Question 3

subclinical stages of kidney dysfunction

Answer 3

normal
intrinsic injury

can get compensation from other kidney to maintain function

can fully recover from these stages

Question 4

clinical stages of kidney dysfunction

Answer 4

structural damage
kidney failure

can NOT compensate completely

can NOT fully recover - recovery will initiate progressive damage pathways

Question 5

kidney markers during CKD stage 1

Answer 5

creatinine WNL

Question 6

kidney markers during CKD stage 2

Answer 6

detectable loss of functional renal mass (>75%)

creatinine above normal ranges

Question 7

kidney markers during CKD stages 3/4

Answer 7

small decreases in GFR (small losses of renal mass) cause large increases in serum creatinine

Question 8

what is a hallmark feature of CKD

Answer 8

progression even after initial injury is resolved

causes kidney functional markers to increase exponentially

Question 9

what does inverse creatinine measure

Answer 9

linearizes the rate of change in kidney function over time to predict progression of CKD

Question 10

negative slope on inverse creatinine graph

Answer 10

progressive disease

Question 11

positive/no slope on inverse creatinine graph

Answer 11

stable/unchanging renal function

Question 12

how does the kidney respond during CKD

Answer 12

compensation - remaining nephrons will hypertrophy to maintain global GFR

Question 13

clinical signs of early stage CKD

Answer 13

PU/PD
anorexia
unconcentrated urine
urinary incontinence
weight loss
GI signs

signs of decreased urine concentrating ability show up first

Question 14

clinical signs of advanced stage CKD

Answer 14

occurs at <25-30% remaining functional mass - kidneys unable to compensate/maintain homeostasis

anorexia
vomiting/nausea
weight loss
unthriftiness

Question 15

what does high BUN measure in terms of CKD

Answer 15

progression of clinical signs

affected by extra-renal factors, detects severity of clinical signs

Question 16

high BUN lesion

Answer 16

lingual ulcers

Question 17

uremic syndrome/uremia

Answer 17

elevated metabolic waste products (BUN, creatinine, SDMA, K+)

Question 18

what causes serum K+ to increase

Answer 18

severe disease - less K+ getting excreted

Question 19

what is an example of clinical trade offs in an attempt to regulate solutes

Answer 19

serum phosphate levels

during EARLY CKD:
dec GFR –> inc PO4 –> stimulates FGF-23 and inhibits calcitriol –> leads to PO4 maintenance

BUT - prolonged attempts to regulate PO4 causes PTH stimulation leading to hyperparathyroidism –> CKD-MBD