Stability of continuous renal replacement therapy solutions after phosphate addition: an experimental study

Area of Science:

• Pediatric Nephrology
• Critical Care Medicine
• Clinical Pharmacy

Background:

• Hypophosphatemia is common in critically ill children undergoing continuous renal replacement therapy (CRRT).
• Phosphate supplementation in CRRT fluids can reduce hypophosphatemia incidence.

Purpose of the Study:

• To evaluate the in vitro stability of CRRT solutions after adding phosphate supplements.
• To assess potential precipitation and chemical changes in CRRT fluids with varying phosphate concentrations.

Main Methods:

• CRRT replacement and dialysis fluids were prepared with three phosphate concentrations (2.5, 4.6, 7.7 mg/dL).
• pH, glucose, total calcium, phosphate, and magnesium levels were measured before and at 2, 24, and 48 hours post-addition.
• Macroscopic observation for precipitation was conducted over 48 hours.

Main Results:

• Phosphate concentrations remained stable in the CRRT fluids up to 7.7 mg/dL.
• No significant alterations in pH, glucose, calcium, or magnesium levels were observed.
• No visible precipitation occurred in the solutions up to 48 hours.

Conclusions:

• Phosphate supplementation of CRRT fluids at concentrations up to 7.7 mg/dL is chemically stable.
• The addition of phosphate does not compromise the integrity or stability of CRRT solutions.
• This supports the safe use of phosphate supplements to manage hypophosphatemia in pediatric CRRT.