Clinical Experience with Heat Sterilization for Reprocessing Dialyzers

Use of heat sterilization for dialysis reprocessing offers significant advantages over chemical germicides. Polysulfone dialyzers (Fresenius 60M or 80M) can be sterilized by heating to 105 degrees C for 20 hr, thus permitting clinical trials of this method. One hundred eighty patients received 9,000 treatments. Pyrogenic reactions, sepsis, and subjective symptoms have not occurred. In vitro clearances (Qb 500 ml/min, Qd 800 ml/min) at baseline and after 2-8 uses did not differ (340 +/- 29 vs. 352 +/- 4 ml/min, respectively). KoA determined in vivo did not decrease (baseline 709 +/- 131 vs. 7th use 632 +/- 50 ml/min). Kt/V for urea was not different in 18 patients treated with heat sterilized dialyzers over 6 months when compared with a baseline period with formaldehyde sterilized dialyzers (1.37 +/- 0.12 vs. 1.32 +/- 0.11 at similar time and blood flows). Mean use number was 7.4 (dialyzers limited to 11 uses). Of discarded dialyzers, 44% failed a bedside integrity test (blood side pressurized at > 400 mmHg for 1 min), 36% failed automated fiber bundle or pressure holding tests, 8% had a blood leak, and 12% reached 11 uses. Clinical blood leaks occur in < 0.5% of treatments. Heat sterilization is a safe and effective method of dialysis reprocessing, but quality control of the process is essential. Based on initial clinical experience, heat sterilization of dialyzers for reuse is a promising alternative to chemical disinfection.