Magnesium (Mg) abnormalities, in particular hypomagnesemia, can have serious clinical manifestations. Ionized magnesium is the biologically active and the more clinically important form of magnesium.1-6
Two clinical situations highlight the importance of knowing ionized magnesium (iMg) instead of the total magnesium (tMg).
- The use of calcium chelators such as citrate, which also chelates magnesium, will cause a lower result when measuring biologically active iMg. Hutten et. al. found that patients receiving CRRT with citrate anticoagulation had normal tMg levels, but low iMg levels.7
- In a study done in Surgical ICU patients at Massachusetts General Hospital, 21% of tMg tests which were reported as normal were hypermagnesemic based on iMg exposing patients to potential risks associated with elevated Mg levels. 8
A new document from Nova Biomedical provides the commonly accepted reference ranges for the biologically active ionized magnesium levels in adults and pediatrics and compares those ranges to total magnesium levels: iMg and tMg comparison
Aidian is the proud distributor of Nova Biomedical's blood gas analyzers in the Nordics.
- Jiang et al. Shock 2017;47(3):288-295.
- Escuela et al. Intensive Care Med 2005;31(1):151-156.
- Wilkes et al. Anesth and Analg 2002;95(4):828-834.
- Soliman et al. Crit Care Med 2003;31(4):1082-1087.
- Yeh et al. J Crit Care 2017;42:147-151.
- Huijgen et al. Am J Clin Pathol 2000;114:688-695.
- Hutten et al. Ionized and not total magnesium as a discriminating biomarker for hypomagnesaemia in continuous venovenous haemofiltration patients. Nephrol Dial Transplant, 2021.
- Yeh et al. Total and ionized magnesium testing in the surgical intensive care unit - Opportunities for improved laboratory and pharmacy utilization.