Huijgen H J, Soesan M, Sanders R, Mairuhu W M, Kesecioglu J, Sanders G T
Department of Clinical Chemistry, University of Amsterdam, The Netherlands.
Am J Clin Pathol. 2000 Nov;114(5):688-95. doi: 10.1309/jr9y-pptx-ajtc-qdrd.
We studied the relation between ionized magnesium, total magnesium, and albumin levels in serum of 115 critically ill patients and the role of extracellular and intracellular magnesium in outcome prediction. Levels of serum total and ionized magnesium, serum albumin, and magnesium in mononuclear blood cells and erythrocytes were measured and the APACHE II score and 1-month mortality recorded. Of all patients, 51.3% had a serum total magnesium concentration below the reference range. In 71% of these hypomagnesemic patients, a normal serum ionized magnesium concentration was measured. None of the patients had an intracellular magnesium concentration below the reference limit. Except for serum total and ionized magnesium, none of the magnesium parameters correlated significantly with each other. A significantly negative correlation was found between serum albumin and the fraction ionized magnesium. There was no association between low extracellular or intracellular magnesium and clinical outcome. The observation of hypomagnesemia in critically ill patients depends on which magnesium fraction is measured. The lack of correlation with clinical outcome suggests hypomagnesemia to be merely an epiphenomenon. Reliable concentrations of serum ionized magnesium can be obtained only by direct measurement and not by calculation from serum total magnesium and albumin.
我们研究了115例危重症患者血清中离子镁、总镁和白蛋白水平之间的关系，以及细胞外和细胞内镁在预后预测中的作用。测定了血清总镁和离子镁水平、血清白蛋白水平以及单核血细胞和红细胞中的镁含量，并记录了APACHE II评分和1个月死亡率。所有患者中，51.3%的血清总镁浓度低于参考范围。在这些低镁血症患者中，71%的患者血清离子镁浓度正常。没有患者的细胞内镁浓度低于参考限值。除血清总镁和离子镁外，其他镁参数之间均无显著相关性。血清白蛋白与离子化镁分数之间存在显著负相关。细胞外或细胞内低镁与临床结局之间无关联。危重症患者低镁血症的观察结果取决于所测定的镁组分。与临床结局缺乏相关性表明低镁血症仅仅是一种附带现象。只有通过直接测量才能获得可靠的血清离子镁浓度，而不能通过血清总镁和白蛋白计算得出。
