The K/DOQI guidelines recommend the use of albumin-corrected calcium (Ca), phosphate, parathyroid hormone (PTH) and calcium-phosphate product as therapeutic targets. The two most common assays for measuring albumin yield discordant results in uraemic patients, the Bromcresol purple (BCP) method providing lower albumin values than the Bromcresol green one (BCG). The aim of this study was to assess the impact of the assay on corrected Ca and, thus, on reaching recommended K/DOQI targets for corrected Ca and CaxP product. METHODS: We measured plasma albumin (both by BCG and BCP), total Ca and phosphate in all our chronic hemodialysis (HD) patients. Total Ca was corrected ("adjusted") for albumin level by a formula proposed by the K/DOQI. RESULTS: 89 patients were included, aged 71.2 +/- 11.5 years, on chronic hemodialysis for 29 (1-362) months. Albumin level was 3.78 +/- 0.24 g/dL by BCG and 3.12 +/- 0.27 by BCP ( p < 0.0001). Based on BCG albumin levels there were 12 cases of "hypocalcaemia" (<8.6 mg/dL), 3 cases of "hypercalcaemia" (>10 mg/dL) and 74 cases with "normal" Ca. The corresponding albumin levels were 3.9 +/- 0.2; 3.1 +/- 0.6 and 3.8 +/- 0.2 g/dL, respectively. According to BCP albumin levels, only one patient was labelled as hypocalcaemia , 21 as hypercalcaemia et 67 as "normal" adjusted Ca (albumin 3.1; 3 +/- 0.3 and 3.2 +/- 0.3 g/dL, respectively). Depending on the use of BCG or BCP, a discrepancy was thus observed in 29 cases (32.6%): 18 cases were classified as hypercalcaemia when albumin was measured by BCP but were considered normal using BCG, whereas 11 cases classified as hypocalcaemia with BCG had normal adjusted Ca with BCP. Concerning CaxP product, 7 discrepancies were detected. DISCUSSION AND CONCLUSION: The choice of either BCG or BCP has a major impact on albumin-adjusted Ca and thus on reaching K/DOQI targets for Ca and CaxP product. Clinicians should take this fact into account for the interpretation of laboratory values and the prescription of drugs related to mineral metabolism and dialysate calcium concentration. The type of assay used for the measurement of albumin should also be recorded and its impact taken into account (or corrected) in multicentric studies and registries.
- MeSH
- Blood Chemical Analysis methods standards statistics & numerical data MeSH
- Bromcresol Green MeSH
- Renal Dialysis MeSH
- Calcium Phosphates blood MeSH
- Evaluation Studies as Topic MeSH
- Hypercalcemia diagnosis blood MeSH
- Hypocalcemia diagnosis blood MeSH
- Indicators and Reagents MeSH
- Middle Aged MeSH
- Humans MeSH
- Reference Values MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Serum Albumin analysis MeSH
- Uremia blood therapy MeSH
- Calcium blood MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Comparative Study MeSH
We describe here a newly developed method for a contact-free optical pH measurement in yeast suspensions supplemented with glucose, and containing the pH sensitive triphenylmethane dye bromocresol green. It is suitable for performing the acidification power test (based on measuring the rate of pH drop of yeast suspension caused by active extrusion of acidity from cells after glucose addition) used for assessing yeast vitality in fermentation industries. Using this methodology we monitored the pH in yeast suspensions in the course of acidification in the pH range of 3.5-5.3. Optical pH measurement allows simultaneous testing of several samples, minimizes the sample volume, simplifies sample handling and reduces the hands-on time in sample processing.
- MeSH
- Bromcresol Green analysis MeSH
- Fermentation MeSH
- Glucose metabolism MeSH
- Indicators and Reagents analysis MeSH
- Colorimetry methods instrumentation MeSH
- Hydrogen-Ion Concentration MeSH
- Culture Media, Conditioned chemistry MeSH
- Yeasts metabolism MeSH
- Mycology methods instrumentation MeSH
- Nephelometry and Turbidimetry methods instrumentation MeSH
