Instituto Alfa de Gastroenterologia, Hospital das Clínicas, Universidade Federal de Minas Gerais (UFMG), Rua República Argentina 786, apto. 602, Bairro Sion, CEP 30, 315490, Belo Horizonte, MG, Brazil.
World J Surg. 2010 May;34(5):987-92. doi: 10.1007/s00268-010-0415-6.
The goal of the present study was to investigate the course of ionized calcium after thyroidectomy and to define a cut-off value that indicates symptoms of hypocalcemia.
The sample included 333 patients undergoing thyroidectomy at the University Hospital of UFMG between September 2000 and December 2005. Ionized calcium was determined before and after surgery (days 1, 2, and 30) in all patients and on postoperative days 90 and 180 in those with hypocalcemia. Asymptomatic patients received no calcium replacement therapy, irrespective of calcium concentration. Patients with clinical manifestation of hypocalcemia were treated after laboratory confirmation. The presence or absence of postoperative hypocalcemia was associated with ionized calcium concentration measured on the reported days.
Ionized calcium declined on the first two days after surgery in all patients when compared to preoperative levels (P = 0.000). Forty-seven (34.6%) of the 136 (40.8%) patients with postoperative hypocalcemia had symptoms. Patients with symptomatic hypocalcemia had significantly lower ionized calcium levels than those with asymptomatic hypocalcemia (P = 0.001). Fourteen (4.2%) patients progressed to definitive hypoparathyroidism by the end of 6 months.
Measurement of ionized calcium on postoperative days 1 and 2 is sufficient for the evaluation of post-thyroidectomy hypocalcemia. Ionized calcium concentrations <1.03 mmol/l on postoperative day 1 are indicative of the presence of symptoms and the need for treatment.
本研究旨在探讨甲状腺切除术后离子钙的变化过程，并确定一个能提示低钙血症症状的临界值。
本研究纳入了 2000 年 9 月至 2005 年 12 月期间在 UFMG 大学附属医院接受甲状腺切除术的 333 例患者。所有患者在术前及术后第 1、2 和 30 天（d）测定离子钙，术后第 90 和 180 天（d）测定有低钙血症患者的离子钙。无症状患者不论血钙浓度如何均不接受补钙治疗。出现低钙血症临床表现的患者在实验室确诊后接受治疗。将术后低钙血症的有无与报告日所测离子钙浓度相关联。
与术前相比，所有患者术后前两天的离子钙均下降（P = 0.000）。术后 136 例（40.8%）低钙血症患者中有 47 例（34.6%）出现症状。有症状的低钙血症患者的离子钙水平显著低于无症状低钙血症患者（P = 0.001）。14 例（4.2%）患者在 6 个月内发展为永久性甲状旁腺功能减退症。
术后第 1 和第 2 天测量离子钙足以评估甲状腺切除术后低钙血症。术后第 1 天离子钙浓度＜1.03mmol/L 提示存在症状，需要治疗。
