Measurement of residual glomerular filtration rate in the patient receiving repetitive hemodialysis.

The objective of the current study was to determine the best index of residual glomerular filtration rate (GFR) by comparing simultaneously measured clearances of inulin, 125I-iothalamate, endogenous creatinine, urea and 169ytterbium diethylenetriaminepentaacetic acid (169YB-DTPA) in patients receiving repetitive hemodialysis. In patients with GFR less than 5 ml/min but greater than 1 ml/min, 125I-iothalamate clearance showed the best correlation with inulin clearance. However, creatinine clearance correlated better with inulin clearance than urea clearance and as well as urea + creatinine/2. In the patients with measured GFR less than 1 ml/min, the correlation of 125I-iothalamate, creatinine, urea and urea + creatinine/two clearances with inulin clearance was satisfactory. Similarly, satisfactory correlations were obtained when the relationships were examined across the entire range of measured clearances less than 5 ml/min. A simple, practical method is descriged for the accurate serial measurement of residual GFR in patients receiving repetitive dialysis.