McLeod M K, Monchik J M, Martin H F
Surgery. 1984 Jun;95(6):667-73.
This report details our continued study of the role of ionized calcium (CAI) in the diagnosis of symptomatic primary hyperparathyroidism (HPT) in patients with persistently normal total serum calcium (CAT) or fluctuating normal total serum calcium levels with elevated CAT. A patient was considered to have fluctuating CAT values if at least 40% of the CAT values were within the normal range. Our previous study demonstrated that CAI provided no additional diagnostic benefit in patients with HPT who had persistently elevated CAT levels. This retrospective study adds 15 additional patients to the four previously reported patients whose workup for HPT included normal or fluctuating normal total serum calcium with elevated CAT values. Eighteen of these 19 patients had complications or symptoms referable to HPT. Nine of these patients had renal calculi. CAT was measured by atomic absorption spectroscopy and CAI was measured by a calcium-selective ion flow-through electrode. One hundred fifty-one concurrent preoperative measurements of CAT and CAI from these 19 patients were used for analysis. Overall, 46 (30.5%) of the CAT values were elevated, whereas 134 (88.7%) of the concurrent CAI values were elevated (P less than 0.001). In three of these 19 patients all preoperative CAT values were within normal limits, however, 20 of the 21 (95%) concurrent CAI values were elevated. In the remaining 16 patients the CAT values fluctuated between normal and elevated. In all of these patients, at least 40% of the preoperative CAT values were normal, and in 15 of these 16 patients at least 50% of the preoperative CAT values were within the normal range. In this fluctuating category there were 130 concurrent values of CAT and CAI. Only 46 of these 130 (35.4%) CAT values were elevated, whereas 114 of the 130 (87.7%) CAI values were elevated (P less than 0.001). All patients underwent parathyroid operation; 15 patients had a parathyroid adenoma and four had hyperplasia. The CAI and CAT values returned to normal in all patients subsequent to operation. These data indicate that the measurement of serum ionized calcium appears to play an important role in the identification of symptomatic HPT in patients who have normal or fluctuating normal total serum calcium with elevated CAT values.
本报告详细介绍了我们对离子钙（CAI）在血清总钙（CAT）持续正常或血清总钙水平波动正常但CAT升高的有症状原发性甲状旁腺功能亢进症（HPT）患者诊断中的作用的持续研究。如果至少40%的CAT值在正常范围内，则认为患者的CAT值波动。我们之前的研究表明，对于CAT水平持续升高的HPT患者，CAI没有提供额外的诊断益处。这项回顾性研究在之前报告的4例HPT检查中血清总钙正常或波动正常但CAT值升高的患者基础上，又增加了15例患者。这19例患者中有18例有与HPT相关的并发症或症状。其中9例患者有肾结石。CAT通过原子吸收光谱法测量，CAI通过钙选择性离子流通电极测量。对这19例患者的151次术前CAT和CAI同时测量值进行分析。总体而言，46（30.5%）次CAT值升高，而134（88.7%）次同时测量的CAI值升高（P<0.001）。在这19例患者中有3例所有术前CAT值均在正常范围内，然而，21次同时测量的CAI值中有20次（95%）升高。在其余16例患者中，CAT值在正常和升高之间波动。在所有这些患者中，至少40%的术前CAT值正常，在这16例患者中有15例至少50%的术前CAT值在正常范围内。在这个波动类别中有130次CAT和CAI的同时测量值。这130次CAT值中只有46次（35.4%）升高，而130次CAI值中有114次（87.7%）升高（P<0.001）。所有患者均接受了甲状旁腺手术；15例患者有甲状旁腺腺瘤，4例有增生。术后所有患者的CAI和CAT值均恢复正常。这些数据表明，血清离子钙的测量似乎在识别血清总钙正常或波动正常但CAT值升高的有症状HPT患者中起重要作用。
