SERUM INTACT PARATHYROID HORMONE LEVELS THREE HOURS AFTER TOTAL AND COMPLETION THYROIDECTOMY AS A PREDICTOR OF POST- OPERATIVE HYPOCALCEMIA

Abstract

Introduction:Post-thyroidectomy hypocalcemia is the most common early complication following total and completion thyroidectomy. Early identification of patients at risk is essential to enable timely calcium supplementation, reduce morbidity, shorten hospital stay, and facilitate safe discharge. Owing to its short half life, serum intact parathyroid hormone (iPTH) has emerged as a promising early biochemical marker for predicting postoperative hypocalcemia. Aim:To evaluate the accuracy of serum iPTH measured three hours after total and completion thyroidectomy as an early predictor of postoperative hypocalcemia and assess its role in reducing complications, hospital stay, and readmissions. Methodology:This cross-sectional study was conducted in the Departments of General Surgery and Surgical Oncology, JSS Medical College, Mysuru, between April 2024 and September 2025. Fifty patients undergoing total or completion thyroidectomy were included. Serum iPTH was measured three hours postoperatively, while serum calcium was assessed at 48 hours. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis, logistic regression, and standard diagnostic accuracy measures, with p<0.05 considered statistically significant. Results:Postoperative hypocalcemia developed in 42% of patients. Patients with hypocalcemia had significantly lower three-hour iPTH levels than normocalcemic patients. An iPTH cut-off of <15 pg/mL demonstrated high specificity and positive predictive value for predicting hypocalcemia. ROC analysis showed excellent discriminatory ability, and multivariable analysis confirmed early iPTH as an independent predictor after adjustment for demographic, operative, and pathological factors. Conclusion:Serum iPTH measured three hours after thyroidectomy is a reliable early predictor of postoperative hypocalcemia. Routine early iPTH estimation may facilitate risk stratification, selective calcium supplementation, optimized discharge planning, and reduced hospital stay.