Assessment of kidney function in adults

Kidney function is typically assessed by measuring glomerular filtration rate (GFR), and many approaches have been used. Accuracy demands complex techniques involving the use of exogenous filtration markers (e.g. inulin, iohexol, 99mTc-diethylenetriaminepentaacetic acid, 51Cr-ethylenediaminetetraacetic acid). For most clinical purposes, accuracy is sacrificed to practicality, and the blood marker creatinine (whose concentration has an inverse relationship to GFR) is used instead. Serum (or plasma) creatinine has many limitations as a kidney function test, being affected by a variety of non-renal and analytical factors.