renal function

Question 1

what are the main functions of the kidney

Answer 1

excretory
endocrine
regulatory
metabolism

Question 2

how does the kidney play a role in excreting

Answer 2

excretes waste products and drugs

Question 3

how does the kidney play a endocrine role

Answer 3

erythropoietin production - stimulates RBC prod. in bone marrow
renin production
prostaglandin production

Question 4

how does the kidney play a regulatory role

Answer 4

fluid volume control and composition
BP regulation
blood pH regulation

Question 5

how does the kidney play a role in metabolism

Answer 5

vitamin d metabolism

Question 6

what are routine tests for assessing renal function

Answer 6

plasma
urea
eGFR
urine

Question 7

what does the blood test for creatinine show

Answer 7

(CrCl), increased in decreased function because it is not being excreted (55-125 umol/L)

Question 8

what are the limitations of the Cockcroft and gault equation

Answer 8

assumes average population data
unsuitable for kids and pregnancy
renal function must be stable

Question 9

what shows up in plasma blood tests

Answer 9

creatinine
urea
eGFR

Question 10

what does the blood test for urea show

Answer 10

nitrogenous breakdown product of protein metabolism - usually excreted - <15mmol/L = uraemia - not specific

Question 11

what else can raise urea levels in the blood

Answer 11

dehydration
muscle injury
infection
haemorrhage
excess protein intake

Question 12

what does eGFR mean

Answer 12

calculated using CKI-EPI as a local lab calc

Question 13

what are the stages of renal impairment and the matching eGFR

Answer 13

normal - >90
mild - 60-89
mild/mod - 45-59
mod/sev - 30-44
severe - 15-29
end stage - <15

Question 14

what shows up in urine tests when checking renal function

Answer 14

osmolality
specific gravity
haematuria
mid-stream urine
albumin - creatinine ratio

Question 15

what does the osmolality test show about renal function

Answer 15

high particle conc = high osmolality

Question 16

what does the specific gravity test show about renal function

Answer 16

solute concentration, more = higher gravity

Question 17

what does the haematuria test show about renal function

Answer 17

blood in the urine

Question 18

what does the MSU test show about renal function

Answer 18

UTI

Question 19

what does the albumin:creatinine ratio test show about renal function

Answer 19

predictor of renal disease development albumin should be in blood not urine (alb/cr)

Question 20

what does the proteinuria test show about renal function

Answer 20

albumin should be in blood not urine

Question 21

what are the effects on drug absorption in CKD

Answer 21

uraemia reduces - D&V, GI oedema
red. calc absorption - less vit d activation

Question 22

what are the effects on drug distribution in CKD

Answer 22

less protein and tissue binding

Question 23

what are the effects on drug metabolism in CKD

Answer 23

○ Less vitamin D metabolism (less calcitriol production) = Less calcium absorption from gut and kidneys
○ Less insulin metabolism
Less elimination of pharmacologically active metabolites

Question 24

what are the effects on drug excretion in CKD

Answer 24

○ Less excretion
○ Dose adjustments: Lower dose and/or increased dose interval
○ NO adjustment to LOADING DOSES

Question 25

what characteristics do drugs used in renal impairment ideally need to have

Answer 25

wide therapeutic index
eliminated via liver
not nephrotoxic
not affected by changes in fluid balance. tissue or protein binding