Sacks G S, Brown R O, Dickerson R N, Bhattacharya S, Lee P D, Mowatt-Larssen C, Ilardi G, Kudsk K A
Department of Clinical Pharmacy, University of Tennessee, Memphis, USA.
Nutrition. 1997 Apr;13(4):303-8.
Magnesium (Mg) deficiency, commonly diagnosed as hypomagnesemia based upon low serum Mg concentrations, is a frequent electrolyte abnormality in critically ill patients. Intravenous replacement therapy is empiric and serum Mg concentrations have traditionally been used as guidelines for measuring efficacy. Recent studies have shown that the Mg content of mononuclear blood cells (MBCs) may provide a better index for Mg status than serum concentrations. The purpose of this study was to evaluate the effects of intravenous Mg replacement therapy on MBC Mg content and serum Mg concentrations in critically ill hypomagnesemic patients. Adult patients admitted to the trauma intensive-care unit (ICU) with serum Mg concentration < or = 0.6 mmol/L (< or = 1.5 mg/dL) were considered for study entry. Patients with severe renal disease (Scr > 133 mumol/L), pregnancy, or those who were seropositive for HIV were excluded. Ten patients with moderate (> 0.4-0.6 mmol/L [> 1.0-1.5 mg/dL]) and severe (< or = 0.4 mmol/L [< or = 1.0 mg/dL]) hypomagnesemia received 0.5 and 0.75 mmol/kg of intravenous MgSO4, respectively, over 24 h. MBC Mg content and serum concentrations of magnesium, phosphorus, calcium, sodium, potassium, blood urea nitrogen, creatinine, glucose, and albumin were measured at baseline (0 h), end of infusion (24 h), 36 h, and 48 h. Data were analyzed using ANOVA with repeated measures and a P value < 0.05 was considered significant. Serum Mg concentrations increased significantly from baseline to 48 h (0.5 +/- 0.1 to 0.8 +/- 0.2 mmol/L, P < 0.001). MBC Mg content did not change significantly within the study period (2.6 +/- 1.0 to 3.0 +/- 1.3 fmol/cell, P > 0.7). The doses of MgSO4 (0.5-0.75 mmol/kg) used in this study increased serum Mg concentrations, but did not result in a statistically significant change of MBC Mg content in this group of trauma ICU patients.
镁（Mg）缺乏症通常根据血清镁浓度低被诊断为低镁血症，是危重症患者常见的电解质异常。静脉补充疗法是经验性的，传统上血清镁浓度一直被用作衡量疗效的指标。最近的研究表明，单核血细胞（MBC）中的镁含量可能比血清浓度更能反映镁的状态。本研究的目的是评估静脉补充镁疗法对危重症低镁血症患者的MBC镁含量和血清镁浓度的影响。血清镁浓度≤0.6 mmol/L（≤1.5 mg/dL）的成年创伤重症监护病房（ICU）患者被纳入研究。排除患有严重肾病（Scr>133 μmol/L）、妊娠或HIV血清学阳性的患者。10例中度（>0.4 - 0.6 mmol/L [>1.0 - 1.5 mg/dL]）和重度（≤0.4 mmol/L [≤1.0 mg/dL]）低镁血症患者在24小时内分别接受了0.5和0.75 mmol/kg的静脉注射硫酸镁。在基线（0小时）、输注结束时（24小时）、36小时和48小时测量MBC镁含量以及血清镁、磷、钙、钠、钾、血尿素氮、肌酐、葡萄糖和白蛋白的浓度。使用重复测量方差分析对数据进行分析，P值<0.05被认为具有统计学意义。血清镁浓度从基线到48小时显著升高（0.5±0.1至0.8±0.2 mmol/L，P<0.001）。在研究期间，MBC镁含量没有显著变化（2.6±1.0至3.0±1.3 fmol/细胞，P>0.7）。本研究中使用的硫酸镁剂量（0.5 - 0.75 mmol/kg）提高了血清镁浓度，但在这组创伤ICU患者中，并未导致MBC镁含量出现统计学上的显著变化。
