van den Bergh Walter M, van de Water Jolanda M W, Hoff Reinier G, Algra Ale, Rinkel Gabriel J E
Department of Neurology, University Medical Center, Room G03.228, PO Box 85500, 3508 GA, Utrecht, The Netherlands.
Neurocrit Care. 2008;8(3):413-7. doi: 10.1007/s12028-008-9068-9.
Magnesium treatment in patients with subarachnoid hemorrhage (SAH) can result in hypocalcemia; this hypocalcemia increases the risk of delayed cerebral ischemia (DCI) and poor outcome. We assessed whether low serum levels of total calcium in patients with SAH treated with magnesium is mediated by parathyroid hormone (PTH) or calcitriol, and whether increased PTH or low serum levels of ionized calcium are associated with an increased risk of DCI and poor outcome.
We studied 167 patients included in a randomized, placebo controlled trial on magnesium in SAH. Mean serum magnesium during treatment was related to mean serum levels of ionized calcium, PTH and calcitriol with linear regression. Hypocalcemia (Ca(2+)) and high serum PTH were related to the occurrence of DCI by means of the Cox proportional hazards model and to poor outcome by logistic regression.
Serum magnesium was inversely related to ionized calcium (B = -0.1; 95% CI -0.12 to -0.06), but not to PTH or calcitriol. Neither hypocalcemia nor high serum PTH was related to DCI. Hypocalcemia did not increased the risk for poor outcome (OR 1.2; 95% CI 0.6-2.3). In the subgroup of patients with known PTH (n = 67), high serum PTH increased the risk for poor outcome (OR 5.4; 1.6-18.9).
Magnesium treatment in patients with SAH leads to hypocalcemia without effect on outcome. PTH is related to poor outcome, but this is independent of magnesium therapy.
蛛网膜下腔出血（SAH）患者接受镁治疗可能导致低钙血症；这种低钙血症会增加迟发性脑缺血（DCI）的风险和不良预后的发生几率。我们评估了接受镁治疗的SAH患者血清总钙水平降低是否由甲状旁腺激素（PTH）或骨化三醇介导，以及PTH升高或血清离子钙水平降低是否与DCI风险增加和不良预后相关。
我们研究了167例纳入SAH镁治疗随机安慰剂对照试验的患者。治疗期间的平均血清镁水平通过线性回归与离子钙、PTH和骨化三醇的平均血清水平相关。低钙血症（Ca(2+)）和高血清PTH通过Cox比例风险模型与DCI的发生相关，并通过逻辑回归与不良预后相关。
血清镁与离子钙呈负相关（B = -0.1；95%CI -0.12至-0.06），但与PTH或骨化三醇无关。低钙血症和高血清PTH均与DCI无关。低钙血症并未增加不良预后的风险（OR 1.2；95%CI 0.6 - 2.3）。在已知PTH的患者亚组（n = 67）中,高血清PTH增加了不良预后的风险（OR 5.4；1.6 - 18.9）。
SAH患者接受镁治疗会导致低钙血症，但对预后无影响。PTH与不良预后相关，但这与镁治疗无关。
