Optimal Time for Recirculation with Ultrafiltration to Remove Disinfectant in Reused Dialyzer

The practice of dialyzer reuse is common in developing countries. One essential technique for safe dialyzer reprocessing is to remove disinfectants properly to the recommended standards before treatment initiation, using dialysis machine recirculation with ultrafiltration. This study was conducted to identify the most effective time for carrying out this procedure, and the factors affecting it. We studied 420 high-flux dialyzers with three different membrane types: FB210U (cellulose triacetate), F80S (polysulfone), and Elisio-210HR (polyethersulfone) at four reused cycles (5th, 10th, 15th, and 19th). Peracetic acid was used as the disinfectant at a concentration of 0.16%. The total cell volume (TCV) and clot inspection grade of the reused dialyzer were recorded before the procedure. The optimal time for disinfectant removal was independently determined by two observers using the residual peroxide strip test of the ultrafiltrate. We observed that disinfectant removal was dependent on the recirculation time and became undetectable at 5 minutes. The type of dialyzer had a significant effect on the effective recirculation time (shortest for FB210U followed by Elisio-210HR and F80S; p < 0.001), but the reused number, TCV, and clot inspection grade did not. It is conceivable that the dialyzer membrane type might affect peracetic acid removal. In conclusion, the interval for carrying out dialysis machine recirculation with ultrafiltration depends on the dialyzer type, and 5 minutes is the optimal time for the operation. This result can be implemented to improve further practice in dialyzer reprocessing.