Renal Function Tests Flashcards
Waste product of creatine and phosphocreatine
Creatinine
Absorbs creatinine
Glomerulus
Removes creatinine
Kidneys
To which the amount of creatinine that is measured in blood is proportional
Patient’s lean muscle mass
Renal physiology
(Review)
Best substance to use for glomerular clearance
A chemical that is filtered completely through the glomerulus and not reabsorbed through the nephron tubule
Creatinine closely meets the criteria for a substance to be used flor glomerular clearance. Why?
1 Endogenous substance
2 Only around 10% pass through the tubules
3 Creatinine production is constant over time
Exogenous substance that must be introduced into the body that can be used for the evaluation of glomerular clearance
Inulin
Specimens used for Jaffe reaction
1 Serum
2 Plasma
3 Urine
Creatinine reference range: Male (Jaffe)
0.9-1.3 mg/dL
Creatinine reference range: Female (Jaffe)
0.6-1.1 mg/dL
Creatinine reference range: Children (Jaffe)
0.3-0.7 mg/dL
Jaffe reaction
Creatinine reacts with picric acid in an alkaline environment to generate an orange-red product
Generate orange-red color in Jaffe reaction
1 Protein 2 Glucose 3 Ascorbic acid 4 Acetone 5 Acetoacetate 6 Cephalosporins
Used to produce a measurable product that reflects creatinine concentration
1 Creatininase
2 Creatinase
3 Creatinine deaminase (used more frequently)
Factors that may affect creatinine clearance
1 Increased tubular reabsorption of creatinine
2 Reduced creatinine generation from muscle tissue
3 Dietary changes in nitrogenous compounds
Formula used for pediatric patients
Schwarz
Schwarz formula
Estimates creatinine clearance from serum creatinine