Risk Factors Predicting Post-Thyroidectomy Hypocalcemia

Background: The most frequent side effect after a total thyroidectomy is post-thyroidectomy hypocalcemia, which is linked to serious morbidity and an extended hospital stay. Early detection of at-risk patients continues to be a clinical problem. Aim: This study aimed to identify risk factors associated with post-thyroidectomy hypocalcemia and to evaluate the predictive value of early postoperative serum intact parathyroid hormone (iPTH). Methods: This prospective study included 30 patients undergoing total thyroidectomy at Zagazig University Hospitals. Preoperative clinical and laboratory assessments were performed for all patients. Postoperative monitoring included measurement of serum iPTH at 6 hours and serum calcium at 24 hours. Patients were classified into hypocalcemia and non-hypocalcemia groups. Statistical analysis was performed to identify significant risk factors and to assess the predictive accuracy of iPTH using ROC curve analysis. Results: Post-thyroidectomy hypocalcemia occurred in 33.3% of patients, with transient hypocalcemia in 30.0% and permanent hypocalcemia in 3.3%. Malignancy, neck dissection, and inadvertent parathyroid excision were significantly associated with hypocalcemia. Patients with hypocalcemia had significantly lower postoperative calcium and iPTH levels (p < 0.001). ROC analysis identified a cutoff value of ≤ 15 pg/mL for postoperative iPTH, with sensitivity of 85.71%, specificity of 81.25%, and AUC of 0.821. Multivariate analysis revealed that postoperative iPTH < 15 pg/mL and neck dissection were independent predictors of hypocalcemia. Conclusion: Early postoperative iPTH measurement is a reliable predictor of post-thyroidectomy hypocalcemia and can facilitate early risk stratification, targeted management, and safe early discharge. ？