HDCN Article Review/Hyperlink

Swan Sk, Nalstenson CE, Kasiske BL, Collins AJ

Determination of residual renal function with iohexol clearance in hemodialysis patients

Kidney Int (Jan) 49:232-235 1996

Residual renal function (RRF) may contribute substantially to the total clearance of waste products in dialysis patients and should be considered when using Kt/V for establishing a dialysis prescription. The need for 24-urine collections or the use of markers that require special handling, such as, radioactive materials complicates the measurement of RRF. Iohexol clearance has been shown to be a marker of the glomerular filtration rate in patients with normal and impaired renal function. Investigators from Minneapolis used the iohexol clearance to estimate RRF in hemodialysis patients and compared iohexol clearance to urea clearance. They gave an intravenous bolus of iohexol to 42 hemodialysis patients through their venous return lines at the end of a dialysis treatment. Just before the next dialysis treatment, 44 hours later, they obtained a single blood sample for the measurement of iohexol plasma concentration. Iohexol-derived RRF did not differ from urea-derived RRF. The RRF contribution to the weekly dialysis prescription, Kt/V, did not differ when they compared iohexol-derived RRF with urea derived RRF.

Comment: This study shows that the single point determination of iohexol clearance is an accurate measure of RRF in HD patients and may simplify the measurement of RRF in hemodialysis patients. This technique seems safe, accurate, and is convenient, in that it requires a single blood test and no urine collection. (George R. Aronoff, M.D.)