Ionized and not total magnesium as a discriminating biomarker for hypomagnesaemia in continuous venovenous haemofiltration patients
Tim J A Hutten, Maaike A. Sikma, Ron H Stokwielder, Marjon Wesseling, Imo E. Hoefer, Wouter M. Tiel Groenestege
Abstract
Magnesium is the second most abundant intracellular cation and plays an essential role as a cofactor in hundreds of enzymatic reactions [1]. In plasma, ~70% of magnesium exists as the bioactive ionized form and is maintained within a narrow range [2]. Magnesium dysregulation mainly impacts neuromuscular and cardiovascular function and can even result in seizures and coma. Hypomagnesaemia is a common phenomenon occurring in 12% of hospitalized patients and up to 65% of critically ill patients [3, 4]. Hypomagnesaemia in critically ill patients is associated with a higher risk of ventilator support, sepsis and mortality [5–7]. Magnesium status can be measured extracellularly in plasma or intracellularly in erythrocytes, skeletal muscle, peripheral lymphocytes and bone. Thus far, techniques for intracellular magnesium measurement have not been readily available and current evidence is inadequate supporting intracellular magnesium as an indicator for magnesium status [...