Perioperative Parathyroid Hormone Assay for Diagnosis and Management of Postthyroidectomy Hypocalcemia

Abstract

The purpose of this study was to assess the relationship between perioperative changes in parathyroid hormone (PTH) level and the likelihood of postthyroidectomy hypocalcemia. In a series of 78 patients undergoing total or completion thyroidectomy, PTH levels were measured before surgery and at 10 minutes after removal of the thyroid gland. A prospective, nonrandomized collection of serum from 78 consecutive total or completion thyroidectomy procedures performed by a single surgeon was carried out over 18 months. Analysis is made of PTH levels, serum calcium values, need for calcium supplementation, and symptoms of hypocalcemia. Both a PTH change of 75% and an absolute postoperative PTH of 7 pg/mL are accurate standards for predicting symptomatic hypocalcemia after total or completion thyroid surgery. Perioperative PTH levels are a tool for the prediction of postoperative symptomatic hypocalcemia after thyroidectomy. A PTH level drawn 10 minutes after removal of the thyroid predicts the likelihood of postoperative hypocalcemia.