Correction formula for creatinine concentration with glucose in dialysate

Area of Science:

• Nephrology
• Clinical Chemistry
• Biomedical Engineering

Background:

• High glucose concentrations in peritoneal dialysis (PD) fluid can interfere with creatinine measurements.
• This interference may lead to inaccuracies in assessing PD treatment effectiveness and patient outcomes.
• Accurate creatinine measurement is essential for clinical decision-making in PD.

Purpose of the Study:

• To evaluate the impact of glucose on creatinine measurements in PD dialysate.
• To compare different methods for correcting creatinine levels in the presence of glucose.
• To determine the most suitable method for clinical practice in PD.

Main Methods:

• Creatinine powder in 0.1 N HCl served as the standard reference.
• Creatinine measurements were performed on unused dialysate solutions with varying glucose concentrations.
• Twardowski's and Tam's formulas were used for creatinine correction.
• Membrane transport characteristics were determined using established criteria for comparison.

Main Results:

• Mean creatinine concentrations varied significantly between the standard method and the two correction formulas.
• Twardowski's formula yielded the lowest mean creatinine concentration.
• High correlation coefficients (r=0.80-0.98) were observed between glucose and creatinine interference with direct measurement and Twardowski's formula.
• Classification of membrane transport characteristics differed based on the correction formula used.

Conclusions:

• Creatinine correction in PD dialysate is critical for accurate results.
• Correction using the ratio of fresh dialysate creatinine and glucose may be clinically practical.
• Accurate creatinine measurements are vital for effective PD management.