Risk of Hypocalcemia and the Need to Augment Calcium Supplementation After Total Thyroidectomy

Hypocalcemia is the most common complication after total thyroidectomy. The aim of this study was to determine the predictors of postoperative hypocalcemia requiring augmentation of routine calcium supplementation. Prospectively collected data of 61 patients who underwent total thyroidectomy from December 2018 to June 2019 was considered for the study. All patients received calcium and vitamin D supplementation after the surgery. In the postoperative period, serum calcium and parathormone (PTH) levels were monitored. The need of additional oral or intravenous (i.v.) calcium supplementation was evaluated as an outcome measure. This cohort comprised 61 patients with median age of 46 years (range 16-80 years) and 49 (80%) females. Central compartment clearance (CCC) was done in 32 patients. Escalation to increased oral and intravenous calcium was required in 15 patients (24.6%) and 2 patients (3.3%), respectively. Serum parathormone level of 11.5 pg/ml on postoperative day 1 predicted the requirement of additional calcium with a sensitivity of 82.4% and specificity of 77.3%. On univariate analysis, serum PTH (p < 0.001), CCC (p = 0.018), and intraoperative parathyroid gland congestion (p = 0.021) predicted the need for escalation of calcium supplementation. On multivariate analysis, only serum PTH showed a significant impact on the need for augmentation of calcium supplementation (p = 0.003). The need for calcium dose augmentation after total thyroidectomy was significantly associated with CCC, parathyroid gland congestion, and serum PTH levels. Intraoperative identification of parathyroid gland congestion and postoperative serum PTH levels is effective in predicting postoperative hypocalcemia with implications on time and cost.