Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 24

Given hypothetical laboratory data, calculate a creatinine clearance and determine whether the result is normal.

Step 1 of 4

Clearance test:

The filtering ability of the glomeruli is measured using the standard tests which are called clearance test.

• It measures the ability of kidney to clear the filterable elements from the blood

Types of clearance test:

• Creatinine

• Beta two-microglobuline

• Cystatin C

Creatinine clearance test:

Creatinine is produced by creatine by the enzyme creatinine phosphokinase as a waste product in the metabolism of muscle.

• This creatinine is used to calculate filtering ability of glomeruli in laboratory

• Creatinine is found constant in blood and it is easy to evaluate the task of glomerulus

• Number of milliliters in specimen is divided by minutes taken to collect the specimen

The formula for determine creatinine clearance is,

(1)

Where,

C = Clearance of creatinine in mL/dL (milliliter per deciliter)

U = Concentration of creatinine in urine in mg/dL (milligram per deciliter)

V = Urine volume in mL per minute

P = Concentration of creatinine in plasma in mg/dL