NPN Flashcards
Used for monitoring renal function
NPNs
It is the major excretory product of protein metabolism
Urea
Its concentration depend on renal function and perfusion
Urea
This is synthesized in the liver from CO2 and ammonia
Urea
It is used to determine nitrogen balance and aid in diagnosis of renal disease
BUN
This is used to verify adequacy of dialysis
BUN
It is the elevated concentration of all NPN in the blood
Azotemia
Increased in urea concentration accompanied by renal failure
Uremia/Uremic syndrome
Dehydration (Pre, Renal or Post renal)
Pre-renal
Shock (Pre, Renal or Post renal)
Pre renal
Decreased renal function (Pre, Renal or Post renal)
Renal
Intrinsic renal disease (Pre, Renal or Post renal)
Renal
Severe infection (Pre, Renal or Post renal)
Post renal
High urea, Normal creatinine
Pre renal
High urea and creatinine
Renal azotemia
Normal urea, high creatinine
Post renal
Condensation with diacetyl monoxime method follows what principle? (Urea determination)
Fearon’s reaction
It is also known as Friedman’s method or Xanthydrol method
Diacetyl Monoxime Method (Urea determination)
Color product from Diacetyl Monoxime method
Yellow diazine derivative
Product of reaction with o-phthaldehyde and naphthylethylenediamine (Urea determination)
Chromogen or colored product
Product of Micro-Kjeldahl Nessler method (Urea determination)
Yellow compound
An enzymatic method for urea determination that uses HCO3 + NH4 + Gum Ghatti (Alkaline) + Nessler reagent
Urease-Nessler’s method
An enzymatic method for urea determination that used sodium nitroprusside (alkaline) and phenol hypochlorite
Urease-Berthelot’s method
Measures the conductivity of ammonium for urea determination
Urease-conductimetric method
Reference method for urea determination that uses isotopically labelled compound
IDMS
Specimens for urea determination
Urine, Serum, and Plasma (Do not use citrate or fluoride)
Serum or plasma reference interval for urea
7-18 mg/dL
Aids in the differentiation of the cause of abnormal urea concentration
Urea N/Creatinine ratio
Normal Urea N/creatinine ratio
10:1 or 20:1
Creatinine is synthesized in the liver from what substances in the body?
Arg, Gly, and Methyl
It is the index of overall renal function
Creatinine
Formula for CrCl
Urine creatinineurine volume/plasma creatininetime
Reference interval of creatinine for males
97-137 mL/min
Female creatinine reference interval
88-128 mL/min
This is NOT sensitive to mild renal dysfunction
Plasma creatinine
A method used for creatinine determination that uses picric acid and 10% NaOH
Jaffe’s method
Janovski complex (Red-orange totomer)
Creatinine Picrate
Jaffe with adsorbent: Reagent used in Fuller’s Earth
Aluminum magnesium silicate
Jaffe with adsorbent: Reagent used in Lloyd’s reagent
Sodium aluminum silicate
Creatinine determination: measures absorbance of NADH
Creatininase-CK
Creatinine determination: This is adapted for use as “dry slide” to replace Jaffe
Creatininase-H2O2
Creatinine determination: Used reagent strip and produces PURPLE compound
DNBA
Highly specific and accepted reference method for creatinine determination
IDMS
This analyte requires non lipemic, non hemolyzed, non icteric serum or plasma but no fasting requirement
Creatinine
Uric acid can cause an increase in this NPN
Creatinine
This causes a negative bias in both Jaffe and enzymatic methods
Bilirubin
Plasma creatinine is ____________ to Creatinine Clearance
Inversely proportional
Creatine can be measured by
HPLC
Plasma creatine is elevated in renal disease (True or False)
FALSE
It is a final breakdown product of purine metabolism
Uric acid
pH: monosodium urate
> 6.8 mg/dL
pH: Uric acid crystal
pH: <5.75
It is used to confirm diagnosis of Gout
Uric acid
Assess inherited disorder of purine metabolism
It is a result of urate precipitation
Gout
Deposition of urate in tissues
Tophi
They have higher risk for hyperuricemia
30-50 years old; menopausal women
Value for hyperuricemia
> 6.0 mg/dL
Seen in patients undergoing chemotherapy
Hyperuricemia
Treatment for hyperuricemia that inhibits Xanthine oxidase
Allopurinol
NOT a good indicator of renal function
Uric acid
A condition with compete deficiency in HGPRT
Lesch-Nyhan syndrome
Lesch-Nyhan syndrome is a disease of what NPN
Uric acid
Toxemia of pregnancy is an increase of
UA
This disease is caused by defective tubular reabsorption (Fanconi’s syndrome) and over treatment with allopurinol
Hypouricemia
It is also known as Caraway or Henry’s method
Direct redox method (UA determination)
This method in UA determination converts ferric ion to ferrous iron
Iron Reduction method
Also known as “Blauck and Koch” method that measures differential absorption of UA and allantoin at 290-293 nm (Near UV)
Uricase method
Remedy in coupled enzymatic method when bilirubin and ascorbic acid destroy peroxide
Addition of potassium ferricyanide & ascorbate oxidase
Reference interval for male UA values
3.7 - 7.2 mg/dL
A result of deamination of amino acid during protein metabolism
Ammonia
Reyes syndrome is a disease of what NPN?
Ammonia
Coagulation tube used for UA determination
Heparinized
Measures volatility of ammonia
Conway method (1935)
Ammonia determination: Cation exchange resin is quantified by___________.
Berthelot’s reaction
Indicator used in “Thin film chromatography”
Bromphenol Blue
Anticoagulation tubes used in Ammonia determination
Heparin or EDTA
RBC contains 2-3x more ammonia than plasma (True or False)
True