Davis K D, Attie M F
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia.
Crit Care Clin. 1991 Jan;7(1):175-90.
Severe hypercalcemia is a medical emergency requiring urgent treatment. It most commonly is caused by malignant tumors, as in the case study, but can also be caused by advanced hyperparathyroidism or high serum levels of vitamin D. The patient described in the case study shows clinical evidence of volume contraction due to hypercalcemia-related anorexia and vomiting. His elevated serum concentrations of urea nitrogen and creatinine reflect intravascular volume depletion and hypercalcemia-induced reduction of renal perfusion. He is also likely to have irreversible renal damage as a result of nephrocalcinosis. His central nervous system depression is most likely a result of hypercalcemia, but other central nervous system disorders such as cerebral metastases should be considered. Appropriate treatment would include intravenous fluids to correct volume depletion, dilute extracellular fluid calcium, and promote renal calcium excretion. Before waiting for the effects of volume expansion, the first dose of an inhibitor of bone resorption should be given. The agent of choice now (this may change when second-generation bisphosphonates become available) is plicamycin. Etidronate is a reasonable second choice. Because both drugs require at least 48 hours before their hypocalcemic action is manifest, calcitonin could be used to accelerate the rate of decline of the serum calcium. As the patient becomes more alert, weight-bearing and ambulation should be encouraged. With this combination of therapeutic modalities, this patient's serum calcium level should be corrected within 3 to 5 days. Intermittent injections of mithramycin or etidronate could be given on an outpatient basis approximately once a week in order to maintain the serum calcium within the normal range. One of the most important aspects of treatment in hypercalcemic patients is eradication of the underlying disease, which usually calls for specific antitumor therapy, including chemotherapy, radiation therapy, or surgery. Most of the agents currently available for the correction of hypercalcemia have cumulative toxicities or are only transiently effective and, therefore, their use should be considered a temporizing measure until specific treatment directed at the primary disease takes effect.
严重高钙血症是一种需要紧急治疗的医疗急症。它最常见的病因是恶性肿瘤，如本病例研究，但也可能由晚期甲状旁腺功能亢进或血清维生素D水平过高引起。本病例研究中描述的患者显示出因高钙血症相关的厌食和呕吐导致容量收缩的临床证据。他血清尿素氮和肌酐浓度升高反映了血管内容量减少以及高钙血症引起的肾灌注减少。他还可能因肾钙质沉着症而出现不可逆的肾损害。他的中枢神经系统抑制很可能是高钙血症的结果，但也应考虑其他中枢神经系统疾病，如脑转移瘤。适当的治疗包括静脉补液以纠正容量不足、稀释细胞外液中的钙并促进肾钙排泄。在等待扩容效果之前，应给予第一剂骨吸收抑制剂。目前的首选药物（当第二代双膦酸盐上市时这可能会改变）是普卡霉素。依替膦酸是合理的第二选择。由于这两种药物至少需要48小时才能显现其降钙作用，可使用降钙素加速血清钙下降速度。随着患者意识恢复，应鼓励其负重和行走。采用这种综合治疗方式，该患者的血清钙水平应在3至5天内得到纠正。可在门诊大约每周一次间歇性注射普卡霉素或依替膦酸，以维持血清钙在正常范围内。高钙血症患者治疗中最重要的方面之一是根除潜在疾病，这通常需要特定的抗肿瘤治疗，包括化疗、放疗或手术。目前可用于纠正高钙血症的大多数药物都有累积毒性或只是暂时有效，因此，在针对原发疾病的特异性治疗生效之前，其使用应被视为一种临时措施。
