Use of glutaraldehyde for disinfection in dialysis

We compared Cidex* HD Disinfecting Solution (CHD), a brand of glutaraldehyde disinfectant, alone and with bleach (B) to formaldehyde (F) with bleach for disinfection and cleaning of hemodialysis equipment. Two Drake-Willock central delivery systems (CDS) with 15 accompanying bedside stations and one Drake-Willock 4216 single patient delivery system (SPS) were used. The CDS designated #1, delivered dialysate to bedside stations 1 through 9, while CDS#2 supplied bedside stations 10 through 16. The study was conducted in three stages. Stage I used F six nights per week and B cleaning Wednesday (CDS#1/SPS) versus F Monday, Wednesday, and Friday with B on Wednesday (CDS#2) for four weeks. Stage II compared CHD six nights/week versus CHD Monday, Wednesday, and Friday for eight weeks. Stage III compared CDH six nights/week with B cleaning on Wednesday versus CHD on Monday, Wednesday, and Friday with B cleaning on Wednesday for four weeks. Samples of pretreated water were collected aseptically on Mondays, Wednesdays, and Fridays each week from the following sites: pre/CDS, inflow Hansen-bedside stations #5, #13, and SPS and pre-blood detector on BS #5, #13, and the SPS. During the study, 763 samples were cultured. Microbiological test results were reported as colony forming units per ml (CFU/ml). The CFU/ml were obtained by filtrating a 10 ml aliquot through a 0.45 μ filter, the filter transferred to a petri dish containing standard plate count agar and counted. Data analysis by non-parametric statistical methods revealed: 1) significantly better disinfection/cleaning when it is performed six nights/week versus three nights/week, 2) CHD alone or with B cleaning is comparable to F/B for reduction of CFU/ml in hemodialysis equipment, and in view of greater acceptance and 3) better detection of residual glutaraldehyde is preferred for increased patient safety. Therefore, the CHD/B system for disinfection and cleaning of hemodialysate delivery systems is more desirable.