How often should water used for hemodialysis be sampled and what should the bacterial counts be?

• A. Monthly; less than 200 bacteria per mL.
• B. Weekly; less than 50 bacteria per mL.
• C. Daily; less than 100 bacteria per mL.
• D. Quarterly; less than 500 bacteria per mL.

Answer: (A)

Regularly checking the microbial quality of water used for hemodialysis is essential because the water directly contacts the patient’s bloodstream via the dialysis circuit. The standard practice is to sample dialysis water monthly and verify that the bacterial count stays below 200 CFU/mL. This frequency provides ongoing protection without being overly burdensome, and the 200 CFU/mL threshold aligns with safety guidelines for acceptable bacterial levels in dialysis water. Sampling more often (weekly or daily) isn’t typically required, while sampling quarterly could miss rising contamination, and a count of 500 CFU/mL would exceed the recommended limit.