CREATININE

CREATININE - serum

Application: Detection of decreased glomerular filtration.
 

Explanation:  Creatinine is a catabolic product of creatine phosphate, which is used in skeletal muscle contraction.  Creatinine is excreted entirely by the kidneys, and so is a direct measure of renal excretory function.

   Increased creatinine levels occur in conditions which decrease the glomerular filtration rate. These may be pre-renal (hypovolemia, hypotension), renal or post-renal (obstruction). Levels are lower in patients with a reduced muscle mass, this may conceal impairment of renal function. Levels may be increased by up to 50% in normal individuals after a large meat meal.
 
Specimen: 5 ml blood in red- or green-top tube.


Reference Interval: Dependent on age.
            0.5-1.1 mg/dL   (Adult Female)
            0.6-1.2 mg/dL   (Adult Male)
            0.5-1.1 mg/dL   (Adolescent)
            0.3-0.7 mg/dL   (Child)
            0.2-0.4 mg/dL   (Infant)
            0.3-1.2 mg/dL   (Neonate)