Gardin J P, Patron P
Rev Prat. 1989 Apr 13;39(11):959-63.
The first thing to do is to confirm that the number of circulating calcium ions has really decreased. This is achieved either by correction of the total blood calcium level, taking into account possible variations in albuminaemia and pH, or by direct measurement of plasma calcium ions, using a special electrode. The aetiological diagnosis may be easy in some clinical situations, but it often demands a systematic approach, which implies a specialized and brief exploration, feasible in out-patients, with simultaneous measurement, under basal conditions, not only of plasma calcium ions, but also of plasma magnesium, intact 1-84 parathyroid hormone (PTH), nephrogenic cyclic AMP and 25 (OH) D. Rationally, hypocalcaemias may be divided into two groups : (1) extraparathyroid, where hyperparathyroidism is constant and hypocalcaemia is due either to calcium intake reduction, vitamin deficiency of high bone accretion, or to a primary renal calcium leakage; (2) parathyroid, by impaired secretion of PTH or alteration of PTH receptors, which means hypoparathyroidism or pseudohypoparathyroidism. The diagnostic and therapeutic possibilities in both groups are discussed.
首先要做的是确认循环钙离子的数量确实减少了。这可以通过校正总血钙水平来实现，同时要考虑到白蛋白血症和pH值的可能变化，或者通过使用特殊电极直接测量血浆钙离子来实现。在某些临床情况下，病因诊断可能很容易，但通常需要系统的方法，这意味着要进行专门且简短的检查，对于门诊患者来说是可行的，同时在基础条件下不仅要测量血浆钙离子，还要测量血浆镁、完整的1-84甲状旁腺激素（PTH）、肾源性环磷酸腺苷和25（OH）D。合理地说，低钙血症可分为两组：（1）甲状旁腺外的，其中甲状旁腺功能亢进持续存在，低钙血症要么是由于钙摄入减少、高骨生长的维生素缺乏，要么是由于原发性肾钙泄漏；（2）甲状旁腺的，是由于PTH分泌受损或PTH受体改变，即甲状旁腺功能减退或假性甲状旁腺功能减退。本文讨论了两组的诊断和治疗可能性。
