module 12 age related changes Flashcards
young and old inc. risk
for fluid and electrolyte imbalances and drug toxicity
infant considerations
early postnatal: GFR is low -> dec. urine, inc. blood volume
dec. ability to make concentrated urine d/t immature kidneys
-> predisposed to volume depletion during fluid losses
volume regulation improves as kidney matures
adult and elderly
kidneys begin to diminish in size and function after 4th decade
geriatric considerations
loss of nephrons
dec. renal blood flow
dec. GFR
dec. ability to conserve salt and water
labs to evaluate kidney function
urine and blood
- urinalysis
- serum creatinine
- blood urea nitrogen (BUN) levels
- GFR tests
urinalysis
odor
- normal: slight d/t breakdown of urea to ammonia
- abnormal: stong ammonia smell
– bacteria, stands for long period of time
- food
color
- normal: pale yellow - amber d/t urochrome pigments
- abnormal: from brown - bright red
– RBC: hematurina
– WBC: cloudy
– dark yellow - orange: concentrated urine
- drugs and food may change color
abnormal UA
fixed osmolality or SG: renal impairment
abnormal substances:
- protein: glomerular injury
- glucose
- excess epithelial, RBC, WBC, and bacteria
- crystals and stones
- casts
– WBC assoc. with renal infection s
– RBC assoc. with glomerulonephritis
– epithelial indicate sloughing of tubular cells (acute tubular necrosis)
creatinine
end product of muscle metabolism excreted exclusively by the kidney
affected by 2 factors:
- rate of creatinine produced, relatively constant in absence of muscle breakdown
- rate of creatinine excreted, determined by GFR
elevated level indicates dec. renal function
Blood urea nitrogen
urea: end product of protein metabolism excreted primarily by the kidney
elevated level indicates
- dec in renal function and fluid volume
- inc. in catabolism and dietary protein intake
measures of GFR
estimated by measuring the clearance of a filterable substance form the urine
creatinine clearance frequently used
inulin clearance is most accurate
renal biopsy
obtain renal tissue to determine nature and extent of renal disease
- used for diagnosis, management, and prognosis
azotemia
inc BUN and creatinine levels
r/t dec. GFR
- assoc. with a number of renal diseases
uremia
elevation of urea in blood
sign of failing kidneys and other metabolic and endocrine abnormalities
proteinuria/albuminuria
inc. concentration of protein in urine
d/t leakiness of glomerular filtration barrier and/or nephron abnormalities
hematuria
blood in urine
