CMS SOM App. H, Tag V234

5.4.4.3 Bicarbonate concentrate mixing systems

Over-agitating or over-mixing of bicarbonate concentrate should be avoided, as this can

cause CO2 loss and can increase pH.

ANSI/AAMI RD52:2004

5.4.4.3 Bicarbonate concentrate mixing systems

Systems designed for mixing dry acid concentrates may use methods that are too vigorous

for dissolving dry bicarbonate.

Interpretive Guidance § 494.40(a)

AAMI Rationale for the Development and Provision of This Recommended Practice

5.4.4.3 Bicarbonate concentrate mixing systems

Over-agitation or mixing of bicarbonate concentrate may result in loss of CO2 from the solution.

Loss of CO2 results in an increase in pH and favors the formation of carbonate that can lead to

precipitation of calcium and magnesium carbonate in the fluid pathways of the dialysis machine

following dialysate proportioning.

Additional Guidance:

There should be a system to prevent over-mixing of bicarbonate. This could include a timer

integrated into the mixing system for automatic cut-off, or a policy to require staff to monitor the

mixer and cut it off immediately when the time period for mixing is completed. Use of over-mixed

bicarbonate concentrate can result in a low calcium level in the dialysate and a concomitant

drop in patients’ serum calcium levels.