Formaldehyde, sodium hypochlorite, and metabisulphite are equally effective as sterilants for central delivery systems.
Sterilants are used to disinfect reverse osmosis (RO) thin film composite membranes or peripheral loop water delivery systems. Formaldehyde (4.0% weight/volume) and metabisulphite (1.0%) were used to sterilize the RO and peripheral loop, and sodium hypochlorite (0.5%) was used to sterilize the peripheral loop with only acid/alkaline treatment of the RO; each sterilant was evaluated for 4 months. Sanitization at the machine was with sodium hypochlorite or glutaraldehyde. Quantitative RO processed water (weekly) and dialysate (4-6 from each station during the period of each sterilant) cultures were obtained. AAMI standards were used (< 200 CFU/ml RO water; < 2,000 CFU/ml dialysate). Bacterial growth exceeded Association for the Advancement of Medical Instrumentation (AAMI) limits in 16% of RO water and 4.7% of dialysate samples, but repeat cultures invariably failed to confirm initial abnormal results. Chi-square analysis showed no differences among sterilants. No difference among sterilants was noted in arithmetic or log10 mean colony counts. Sporadic low level gram positive and gram negative organism growth occurred with all sterilants. Continued "sterility" that met AAMI standards was obtained for 1 year, first with metabisulphite and then with acid/alkaline RO and sodium hypochlorite loop treatment. It is concluded that all three sterilants are effective for disinfection of hemodialysis delivery systems. Sodium hypochlorite is recommended because of its safety advantages and readily available test of adequate removal.
Besarab
A
A
Department of Medicine, Thomas Jefferson College of Medicine, Thomas Jefferson University, Philadelphia, PA 19107.
DeLucia
T
T
Picarello
N
N
Jungkind
D
D
D015169:Colony Count, Microbial; D005557:Formaldehyde / Q000494:pharmacology*; D006801:Humans; D007688:Kidneys, Artificial; D008567:Membranes, Artificial; D009995:Osmosis; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013242:Sterilization / Q000295:instrumentation*; D013447:Sulfites / Q000494:pharmacology*
D008567:Membranes, Artificial; D013447:Sulfites; D005557:Formaldehyde; C030981:metabisulfite; D012973:Sodium Hypochlorite