Maintaining blood compartment volume in dialyzers reprocessed with peracetic acid maintains Kt/V but not beta2-microglobulin removal.

A dialyzer is reused if its blood compartment volume is 80% of its initial value, a condition believed to ensure that the urea clearance remains at 90% of its initial value. This criterion was developed for dialyzers containing low permeability cellulose membranes reprocessed with formaldehyde. We tested the hypothesis that the criterion is also valid for more permeable membranes when dialyzers are reprocessed with peracetic acid/hydrogen peroxide. Kt/V for urea and reduction in beta2-microglobulin concentration were measured for up to 15 uses in dialyzers containing polysulfone or cellulose membranes. Kt/V for urea did not change for either dialyzer provided blood compartment volumes remained 80% of their initial value. The reduction in plasma beta2-microglobulin concentration from predialysis to postdialysis was 30% for the first use of the dialyzer containing polysulfone membranes, but decreased significantly (P = 0.042) following reuse to 12% for the tenth use. For the dialyzers containing cellulose membranes, the reduction in plasma beta2-microglobulin concentration was 18% for the first use and decreased to 12% by the twelfth use; however, this change was not significant. We conclude that removal of urea is maintained during reuse with peracetic acid/hydrogen peroxide provided the blood compartment volume remains 80% of its initial value. However, removal of beta2-microglobulin may not be maintained, even though blood compartment volumes remain at 80% of their initial value.