Ionized calcium and PTH as predictors of hypoparathyroidism following total thyroidectomy

Area of Science:

• Endocrinology
• Surgical Complications
• Biochemistry

Background:

• Post-surgical hypoparathyroidism (POSH) is a frequent complication following total thyroidectomy.
• Early identification of patients at risk for hypocalcemia and parathyroid dysfunction is crucial for timely management.

Purpose of the Study:

• To evaluate the predictive accuracy of serum and ionized calcium and parathyroid hormone (PTH) levels on postoperative day 1 (POD-1) for predicting postoperative hypocalcemia (PoHC), transient hypoparathyroidism (THPT), and permanent hypoparathyroidism (PtHPT).

Main Methods:

• Retrospective analysis of biochemical and clinical data from 200 patients undergoing total thyroidectomy.
• Receiver Operating Characteristic (ROC) curve analysis to determine optimal cut-off values for predictive markers.
• Correlation of biochemical results with clinical variables and patient outcomes.

Main Results:

• PoHC incidence was 46%, THPT 37%, and PtHPT 9% on POD-1.
• Ionized calcium < 4.43 mg/dL on POD-1 demonstrated high accuracy (AUC = 0.9) in predicting PoHC.
• PTH < 8.06 pg/mL on POD-1 predicted PtHPT (AUC = 0.797).
• Multivariate analysis identified low PTH, ionized calcium, and serum calcium on POD-1 as significant risk factors for PoHC.

Conclusions:

• Postoperative day 1 ionized calcium levels are highly accurate predictors of postoperative hypocalcemia.
• Serum PTH levels on POD-1 can indicate an increased risk for developing permanent hypoparathyroidism.