The predictive role of intraoperative parathyroid hormone measurement on postoperative parathyroid function in patients undergoing total thyroidectomy

Hypocalcemia is a common complication of thyroidectomy, particularly total thyroidectomy. The higher incidence of hypocalcemia following total thyroidectomy is primarily due to inadvertent damage to the parathyroid glands during surgery. This study aims to investigate the predictive value of intraoperative parathyroid hormone (IOPTH) in determining hypocalcemia during hospitalization and the recovery of parathyroid function after total thyroidectomy, as well as the factors that may influence IOPTH. In this retrospective study, we analyzed a cohort of 164 patients who underwent total thyroidectomy at our institution between 2018 and 2019. IOPTH was measured either 15 min after bilateral thyroidectomy combined with area VI lymph node dissection, or 15 min after bilateral thyroidectomy alone. We plotted ROC curves for IOPTH and ΔPTH% in relation to hypocalcemia during hospitalization and recovery of parathyroid function. Additionally, we explored risk factors for the development of hypocalcemia during hospitalization and factors that may influence IOPTH. IOPTH and ΔPTH% demonstrated good specificity and sensitivity for predicting hypocalcemia during hospitalization and for assessing recovery of parathyroid function. Lower preoperative PTH levels, chronic lymphocytic thyroiditis, and intraoperative parathyroid auto-transplantation were identified as risk factors for IOPTH < 15 pg/mL. IOPTH and ΔPTH% are predictive of hypocalcemia during the postoperative hospital stay and recovery of parathyroid function. Patients with chronic lymphocytic thyroiditis, intraoperative parathyroid auto-transplantation, and low preoperative PTH levels should be closely monitored for the recovery of parathyroid function after surgery.