Creatinine, Creatinine Clearance
Creatinine is a degradation product of creatine phosphate which serves as a fast energy supplier in muscle tissue. Creatinine as a urinary substance is filtered exclusively in the glomerulus, the determination of its (physiological) clearance of 95-150 ml/min is therefore suitable as a functional test to assess the filtration performance () of the kidney.
Da die Bestimmung der Kreatinin-Clearance von verschiedenen Faktoren (Muskelmasse, Alter, Hautfarbe, Serum-Kreatinin, Geschlecht) abhängig ist, hat man verschiedene Formeln entwickelt, um eine annähernde Bestimmung zu ermöglichen.