Lesson 3 Flashcards
(12 cards)
GLOMERULAR FILTRATION TESTS
_____: standard test used to determine filtering capacity of glomeruli
- method of choice if suitable substance is already present in the body
- substances used are not inherently produced by the body
- requires infused substances (3)
Clearance Test
- ENDOGENOUS PROCEDURE
- EXOGENOUS PROCEDURE
- I-iothalamate
- I-diatrizoate
- Cr-EDTA
ENDOGENOUS PROCEDURE
_____: earliest glomerular filtration test
1. ___ was measured
2. approx. ____ of filtered urea is reabsorbed
3. patients were hydrated to produce urine flow of ____
- to ensure no __ than 40% of urea was reabsorbed
UREA CLEARANCE TEST
1. UREA
2. 40%
3. 2mL/min
- more
ENDOGENOUS PROCEDURE
_____: most commonly used clearance test for routine assessment of GFR
1. waste product of muscle metabolism
2. produced at steady rate, resulting in constant ____ & constant _____
3. GFR is reported in ____
4. ______ urine specimen is collected
5. formula = ___
- C = clearance of substance in ____
- U = urine conc. of substance being tested in _____
- P = plasma conc. of substance being tested in _____
- V = volume of urine excreted in ____ (hrs)
6. male normal
7. female normal
CREATININE CLEARANCE TEST
1. CREATININE
2. constant plasma conc. & constant urine excretion rate
3. ml/min
4. 24-hr
5. C = U x V / P
- milliliters per minute
- mL/dL
- mg/dL
- timed collection (24hrs)
6. 107-139 ml/min
7. 87-107 ml/min
EXOGENOUS PROCEDURE
_____: reference method for GFR determination
- ____ is not reabsorbed by GIT
ADDITIONAL TESTS TO ASSESS KIDNEY FUNCTION
____: more sensitive in detecting kidney fxn problems than decreased GFR
1. essential in monitoring ___ & ___
2. necessary to calculate _____ and to adjust
______ to account for patient’s renal function
EXOGENOUS PROCEDURE
INULIN CLEARANCE TEST
- exogenous nontoxic fructopolysaccharide
ADDITIONAL TESTS TO ASSESS KIDNEY FUNCTION
CYSTATIN C
1. RENAL DISEASE & RENAL FAILURE
2. therapeutic drug dosages; medications
ADDITIONAL TESTS TO ASSESS KIDNEY FUNCTION
____: w/ normal renal fxn, this in plasma remains constant, and its
excretion in urine is low
- It is completely reabsorbed by ______
- better marker of reduced ______ than of glomerular fxn
- Disadvantage:
____: screen people w/ chronic conditions such as diabetes & hypertension w/
developing kidney disease
- aka
1. detection is marker of _____
2. (+) = microalbumin to creatinine ration of ___
β2-microglobulIn
1. proximal tubular cells
2. reduced renal tubular fxn
3. degradation in acidic environment
Microalbumin
- albumin/creatinine ratio
1. marker of increased cardiovascular morbidity & mortality
2. >30mg/g
Calculated Glomerular Filtration Estimates provides estimates of GFR based on _______
- older & most commonly used equation for estimating creatinine clearance
- preferred for
- multiply results by ___ for female patients - most widely used to estimate GFR; used for eGFR calculations
- only useful when _____
- not recommended for : _____ or _____
serum creatinine w/o urine creatinine
- Cockcroft-Gault Formula
- calculating drug dosages
- 0.85 - Modification of Diet in Renal Disease (MDRD) System
- renal function is stable
- <18 & those w/ extremes in muscle mass or diet
TUBULAR REABSORPTION TESTS
both are _____ to determine ____
- preferred for evaluation of renal
concentrating ability - easier & requires less time to perform
- more accurate assessment
- affected by some solutes
- small quantities of high MW substances _______ osmolality
- small quantities of high MW substances _______ specific gravity
NONSPECIFIC test, urine conc
- Osmolality
- Specific gravity
- Osmolality
- Specific gravity
- do not affect
- affect
TUBULAR REABSORPTION TESTS
_____: to differentiate cause of water diuresis; evaluates ability of renal tubular
cells to selectively absorb & secrete solutes
- patient eats a normal evening meal, and the next day from ___ to ___, patient is deprived of fluid intake
- At ____ urine specimen is collected and osmolality is determined
- if urine osmolality is ____ = normal
- if urine osmolality is ____ = deprivation continues until
10am
- if urine osmolality is <800 mOsm/kg, and if urine/serum
osmolality ratio is >3.0 = ____ is demonstrated - if neither condition is met:
- ____ is administered
- at ___ & ____ = serum & urine are collected osmolality testing
Fluid Deprivation Tests
- 6 pm to 8 am
- 8am
- >800 mOsm/kg
- <800 mOsm/kg
- normal renal concentrating
- ability - if neither condition is met:
- antidiuretic hormone
- 2&6pm
Fluid Deprivation Tests:
- involves measuring urine specific gravity after a 24-hour fluid deprivation
- specific gravity is ___ = normal - volume and specific gravity comparison of day and night urine samples
- then requires 24hr collection = ____ are collected
- ____ urine volume > ____ volume
- by nighttime sg should be _____
- Fishberg Concentration
- > or equal 1.025 - Mosenthal’s Test
- 2 separate 12-hr urine collections
- daytime urine volume > nighttime volume
- > or equal 1.020
ration of urine to serum osmolarity can be further expanded by _____
- formula
- values
- possible state of dehydration
- no renal concentration or dilution
- excess water would have been excreted
Free Water Clearance Test
- Cosm = (Uosm x V) / Posm
- values
- -2.0
- 0
- +2
TUBULAR SECRETION
- completely removed
- as blood passes thru _____
- most common test used to measure
- provides excellent indicator of - not completely removed
- as it passes thru ____ - evaluates unilateral kidney disease
- intravenous administration of
- p-aminohippurate Test
- peritubular capillaries
- measure renal plasma flow
- indicator of renal tubular secretory function - Phenolsulfonphthalein Test
- kidneys - Indigo Carmine Test
- 100mg indigo carmine
TUBULAR SECRETION
- ability of renal tubules to excrete acid in urine
- sample
- collection at
- oral administration of
- acidic urine is titrated with _____
- to ensure point of pH ____ & urine pH of ____
- Measurement of Titrable Acid & Urinary Ammonia
- fresh/ toluene-preserved urine
- 2hr intervals
- ammonium chloride
- 0.1N NaOH (sodium hydroxide)
- pH of 7.4 & urine pH of 4.4
