Earlier Prediction of Hypocalcemia by Postoperative Second Hour Parathyroid Hormone Level after Total Thyroidectomy

Context Thyroidectomy is becoming an ambulatory surgical procedure. By predicting hypocalcemia,duration of hospital stay might decline. We tried to determine whether measuring parathormone two hours after total thyroidectomy predicts hypocalcemia. Objective We aimed to design a protocol for early prediction of hypocalcemia by defining PTH measurement time and cut-off value of our center. Design One hundred and six patients undergoing total thyroidectomy between November 2017 and October 2018 were prospectively studied. Methods Pregnant women, patients with renal failure, parathyroid disease, previous neck operation and thyroid malignancy requiring neck dissection were excluded from the study. Parathormone (PTH) and calcium measurement was done preoperatively and in the postoperative second hour. Results Group 1 consisted of 75 normocalcemic patients while group 2 had 31 hypocalcemic patients. Mean age was 45±13.1 (age range: 18-76). Female/male ratio was 82/24. While with a 8.36 pg/mL postoperative second hour PTH, hypocalcemia can be predicted with a 51.5% sensitivity and 90.7% specificity while with a PTH decline of 40.8% hypocalcemia can be diagnosed with a 83.9% sensitivity and 52% specificity. Conclusion Postoperative second hour PTH and PTH percentage decline can predict postoperative hypocalcemia in total thyroidectomies. Preoperative Dual-energy X-ray absorptiometry (DXA) was not found useful in hypocalcemia prediction.