The effect of dialyzer reuse on dialysis delivery.

It is well documented that the reprocessing of dialyzers may reduce their solute clearance capabilities. However, the effect of dialyzer reuse has never been assessed in an uncontrolled clinical practice setting. We addressed this issue in a prospective 436-patient, 34-center study. All patients underwent formal urea kinetic modeling monthly, usually for 3 sequential months. Dialyzers were reprocessed and reused in the usual manner for each unit. As a result, urea kinetic modeling was performed in individual patients using dialyzers with differing numbers of prior uses. For each patient, Kt/V urea for the treatment using the dialyzer with the most reuses (mean, 13.8) was compared with that with the treatment using the dialyzer with the fewest reuses (mean, 3.8). The mean Kt/V delivered for high reuse treatments was significantly lower than that for low reuse treatments (1.05 v 1.10, P = 0.002). Prescribed Kt/V in high and low reuse treatments was identical. Individual centers appeared to differ substantially (P = 0.06) in the effect of reuse on delivered Kt/V. Of the 23 centers using formalin-based reprocessing, an average difference of > or = 0.12 (mean, 0.17) in Kt/V between high and low reuse treatments was seen in 10 centers. Dialyzer reprocessing significantly impairs dialysis delivery, an effect that may be related to the methods and procedures in individual dialysis centers.