Estimating Weekly Urine Flow Rate And Residual Kidney Urea Clearance: A Method To Deal With Interdialytic Variability.

Both urine volume and residual kidney clearances are known to increase over the course of an interdialytic interval. However, no strategy has been proposed for adjusting data from an interdialytic urine collection to a weekly value for urine flow rate or residual kidney urea clearance. Data from a reanalysis of published results allows a proposal for such an adjustment, which assigns a relative value to each dialysis day of the week based on its distance from a preceding hemodialysis treatment. The strategy also identifies which urine collection periods and interdialytic intervals give results that should be most representative of weekly average values.