An optical method for serum calcium and phosphorus level assessment during hemodialysis

Area of Science:

• Nephrology
• Biomedical Engineering
• Clinical Chemistry

Background:

• Hemodialysis patients face low survival rates, significantly impacted by prevalent vascular calcification (VC) and cardiovascular disease.
• Elevated serum phosphorus (P) and calcium (Ca) are key contributors to VC development in this population.

Purpose of the Study:

• To investigate the feasibility of using optical monitoring of spent dialysate for real-time assessment of serum P and Ca levels during hemodialysis.

Main Methods:

• Collected spent dialysate from 28 hemodialysis patients across Estonia and Sweden.
• Assessed serum Ca and P levels using an optical method (absorbance and fluorescence) on the spent dialysate.
• Compared optical method results with standard laboratory measurements.

Main Results:

• Mean serum Ca levels were 2.54 ± 0.21 mmol/L (lab) vs. 2.53 ± 0.19 mmol/L (optical).
• Mean serum P levels were 1.08 ± 0.51 mmol/L (lab) vs. 1.08 ± 0.48 mmol/L (optical).
• No significant difference (p = 0.5) was found between the methods, with Bland-Altman limits of agreement of -0.19 to 0.19 for Ca and -0.37 to 0.37 for P.

Conclusions:

• Optical monitoring of spent dialysate is a feasible approach for assessing serum Ca and P levels during hemodialysis.
• This technique can provide valuable, continuous patient data to medical staff, potentially aiding in managing VC and cardiovascular risk.