Cardiff and Vale University Health Board, UK.
Ann R Coll Surg Engl. 2023 Feb;105(2):157-161. doi: 10.1308/rcsann.2022.0007. Epub 2022 Apr 21.
This study aimed to identify patients at risk of long-term hypocalcaemia following total thyroidectomy for Graves' disease, and to determine the thresholds of postoperative day 1 serum calcium and parathyroid hormone (PTH) at which long-term activated vitamin D treatment can be safely excluded.
This study was a retrospective analysis of 115 consecutive patients undergoing total thyroidectomy for Graves' disease at a university referral centre between 2010 and 2018. Outcome measures were the day 1 postoperative adjusted calcium and PTH results, and vitamin D analogue need at 6 months postoperatively. Logistic receiver operating curves were used to identify optimal cut-off values for adjusted serum calcium and serum PTH, and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated.
Temporary hypocalcaemia was observed in 20.9% of patients (mean day 1 serum adjusted calcium 2.2±0.14mmol/l and PTH 4.15±2.42pmol/l). Long-term (>6 months) activated vitamin D analogue therapy was required in five patients (4.3%), four of whom had normal serum PTH and one with undetectable PTH at 6 weeks post surgery. No patient with a day 1 postoperative calcium >2.05mmol/l and detectable PTH required vitamin D supplementation at 6 months post surgery (100% sensitivity, PPV 50%, NPV 100%).
The biochemical postoperative day 1 thresholds identified in this paper have a 100% NPV in the identification of patients who are likely to require either no or only temporary activated vitamin D supplementation. We were able to identify all patients requiring activated vitamin D supplementation 6 months postoperatively from the day 1 postoperative serum calcium and PTH values, while excluding those that may only need temporary calcium supplementation. These threshold levels could be used for targeted follow-up and management of this subset of patients most at risk of long-term hypocalcaemia.
本研究旨在确定 Graves 病行甲状腺全切除术患者发生长期低钙血症的风险，并确定术后第 1 天血清钙和甲状旁腺激素 (PTH) 的阈值，以便安全排除长期使用活性维生素 D 治疗。
这是一项对 2010 年至 2018 年期间在大学转诊中心行甲状腺全切除术治疗 Graves 病的 115 例连续患者进行的回顾性分析。观察指标为术后第 1 天校正后的血钙和 PTH 结果，以及术后 6 个月维生素 D 类似物的需要量。使用逻辑接收器工作曲线来确定调整后血清钙和血清 PTH 的最佳截断值，并计算灵敏度、特异性、阳性预测值（PPV）和阴性预测值（NPV）。
20.9%的患者（平均第 1 天血清校正钙 2.2±0.14mmol/l，PTH 4.15±2.42pmol/l）出现暂时性低钙血症。5 例（4.3%）患者需要长期（>6 个月）使用活性维生素 D 类似物治疗，其中 4 例术后 6 周 PTH 正常，1 例 PTH 不可检测。术后第 1 天血钙>2.05mmol/l 且 PTH 可检测的患者术后 6 个月无需补充维生素 D（100%的敏感性，PPV 50%，NPV 100%）。
本文确定的术后第 1 天生化阈值在识别需要补充活性维生素 D 的患者中具有 100%的阴性预测值（NPV），且只需补充短期活性维生素 D。我们能够根据术后第 1 天的血清钙和 PTH 值确定所有需要补充活性维生素 D 的患者，同时排除仅需要短期补钙的患者。这些阈值水平可用于对最易发生长期低钙血症的这部分患者进行有针对性的随访和管理。
