NPNs: Creatinine Flashcards
Waste product of MUSCLE METABOLISM
Creatinine
Index for OVERALL RENAL FUNCTION
Creatinine
Evaluates the completeness of 24-hr urine collection
Creatinine
Creatinine value that shows incomplete 24-hr urine collection
<0.8g
Evaluates fetal kidney maturity
Creatinine
Creatininine RV:
Male:
Female:
Male: 0.9 - 1.3 (80-115 umol/L)
Female: 0.6 - 1.1 (53-97 umo/L)
Test that provides estimates of amount of PLASMA THAT FLOWED THROUGH KIDNEY GLOMERULI PER MINUTE
Creatinine Clearance
Creatinine is freely filtered by the glomeruli but
NOT REABSORBED
Creatining Clearance specimen
Plasma
24-hr Urine
Creatinine Clearance RV:
Male:
Female:
Male: 85-125 mL/min
Female: 75-112 mL/min
Prediction equation for patients with CKD:
Cockcroft-Gault Equation
Cockcroft-Gault Equation includes Px criteria: (4)
Age
Weight
Serum Creatinine
Gender
Uses only BLOOD CREATININE and MDRD (Modification of Diet in Renal Disease)
estimate Glomerular Filtration Rate
Creatinine Test that requires correction of gender and race
eGFR
eGFR includes:
Serum Creatinine
Age
BUN
Albumin
Gender
Race
CREATININE CHEMICAL METHODS:
Rapid, Sensitive and Specific
Colorimetric, Kinetic
CREATININE CHEMICAL METHODS:
Simple, Non-specific
Colorimetric, END-POINT
CREATININE CHEMICAL METHODS:
Uses Jaffe Reaction; Color produced in Jaffe reaction
Direct Jaffe Reaction
Red-Orange
CREATININE CHEMICAL METHODS:
Reagent used in Direct Jaffe Reaction
Alkaline Picrate (saturated picric acid and 10% NAOH)
CREATININE CHEMICAL METHODS:
Tests under Direct Jaffe Method (2)
- Folin-Wu Method
- Lloyd’s and Fuller Earth method
CREATININE CHEMICAL METHODS:
Direct Jaffe Method that is SENSITIVE BUT NOT SPECIFIC ; affected by Bilirubin and Hgb (F. dec.)
Folin-Wu Method
CREATININE CHEMICAL METHODS:
Direct Jaffe Method that is SENSITIVE AND SPECIFIC but time consuming and not readily automated
lloyd’s and Fuller Earth
CREATININE CHEMICAL METHODS:
Direct Jaffe Method:
Reagent used in LLoyd’s”
Reagent used in Fuler Earth’s:
Reagent used in LLoyd’s:
SAS - Sodium Aluminum Silicate
Reagent used in Fuller Earth’s:
AMS
Aluminum Magnesium Silicate
CREATININE CHEMICAL METHODS:
Principle: Colorimetry-Spectrophotometry
Rate of CHANGE IN ABSORBANCE is measured between 2 points
Rapid, Inexpensive, Easy to perform
Kinetic Jaffe Method
More specific than Jaffe Method
Interference: Bilirubin and Catecholamines
Enzymatic Method
Creatinine Enzymatic Method:
Uses Creatininase, CK, PK, LDH
Measure: disappearance of NADH
Creatininase-CK Method
Creatinine Enzymatic Method:
- More specific than Jaffe Method
- Not interfered by ACETOACETATE and CEPHALOSPORIN
- Used in Dry Slide Method
Creatininase-Hydrogen Peroxide Method
Creatininase-Hydrogen Peroxide Method endproduct
RED benzoquinoneimine dye
Reference Method for Creatinine
Quantification of isotopically labeled compound
IDMS
Isotope Dilution Mass Spectrophotometry
Better Indicator of source of elevation of either substance
BUN : CREATININE RATIO
BUN : CREATININE RATIO
Reference Value:
10:1 - 20: 1
Acute Tubular Necrosis
Low Protein Intake
Starvation
Vomiting
Repeated Dialysis
Low Ratio <10:1
Prerenal Azotemia
High Protein Intake
Dehydration
Muscle Wasting
High Ratio >20:1
w/ Normal Creatinine
Post Renal Obstruction (Nephrothiliasis)
Prostitis
Severe Infection
Acute Renal Failure
High Ratio >20:1
High Creatinine
End-stage renal disease
Chronic Renal Failure
Normal Ratio
High BUN and Creatinine (sabay nagiincrease)
