What is the maximum total microbial count allowed in dialysate water for conventional dialysis according to AAMI standards?

• A. 20 CFU/mL
• B. 200 CFU/mL
• C. 100 CFU/mL
• D. 2000 CFU/mL

Answer: (B)

Keeping dialysate water microbiologically safe is essential because water directly interfaces with the patient during dialysis, so any microbial contaminants can enter the bloodstream via the dialyzer. AAMI standards set a specific upper limit for conventional dialysis water to minimize infection risk while keeping practical operations feasible. The maximum allowed total microbial count is 200 colony-forming units per milliliter (CFU/mL). This value represents the approved threshold for conventional dialysis, balancing safety and practicality.

Twenty CFU/mL would be more stringent than required for conventional dialysis and isn’t the specified limit. One hundred CFU/mL is below the allowable maximum, so it would meet the standard but isn’t the defined maximum. Two thousand CFU/mL would exceed the standard and would not be acceptable.