IFCC Guideline for sampling, measuring and reporting ionized magnesium in plasma
Year: 2007
Type: article
Abstract: Analyzers with ion-selective electrodes (ISEs) for ionized magnesium (iMg) should yield comparable and unbiased results for iMg. This IFCC guideline on sampling, measuring and reporting iMg in plasma provides a prerequisite to achieve this goal [in this document, "plasma" refers to circulating plasma and the forms in which it is sampled, namely the plasma phase of anticoagulated whole blood (or "blood"), plasma separated from blood cells, or serum]. The guideline recommends measuring and reporting ionized magnesium as a substance concentration relative to the substance concentration of magnesium in primary aqueous calibrants with magnesium, sodium, and calcium chloride of physiological ionic strength. The recommended name is "the concentration of ionized magnesium in plasma". Based on this guideline, results will be approximately 3% higher than the true substance concentration and 4% lower than the true molality in plasma. Calcium ions interfere with all current magnesium ion-selective electrodes (Mg-ISEs), and thus it is necessary to determine both ions simultaneously in each sample and correct the result for Ca2+ interference. Binding of Mg in plasma is pH-dependent. Therefore, pH should be measured simultaneously with iMg to allow adjustment of the result to pH 7.4. The concentration of iMg in plasma may be physiologically and clinically more relevant than the concentration of total magnesium. Furthermore, blood-gas analyzers or instruments for point-of-care testing are able to measure plasma iMg using whole blood (with intact blood cells) as the sample, minimizing turn-around time compared to serum and plasma, which require removal of blood cells.
Authors: International Federation of Clinica Ben Rayana, Robert W. Burnett, Arthur K. Covington, Paul D'Orazio, Niels Fogh-Andersen, Ellis Jacobs, Wolf R. Külpmann, Katsuhiko Kuwa, Lasse Larsson, Andrzej Lewenstam, Anton H.J. Maas, Gerhard Mager, Jerzy W. Naskalski, Anthony O. Okorodudu, Christoph Ritter, Andrew St John
Institutions: Institut National de Nutrition et de Technologie Alimentaire, Hartford Hospital, Newcastle University, University of Copenhagen, Wadsworth Center, Medizinische Hochschule Hannover, University of Tsukuba, Linköping University, Åbo Akademi University, Eurotransplant, Fresenius (Germany), Jagiellonian University, The University of Texas Medical Branch at Galveston, F. Hoffmann-La Roche AG, Australian Research Council
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2021850993