Publication:

Early prediction of hypocalcaemia following total thyroidectomy by serial parathyroid hormone and ionized calcium assay

Background Total thyroidectomy is an accepted treatment modality for benign and malignant thyroid disease. Postoperative transient hypoparathyroidism leading to hypocalcaemia is one of the most frequent morbidities following total thyroidectomy.

Methods 30 patients were included in this study, underwent total thyroidectomy and completion thyroidectomy. All measures for the preservation of parathyroid glands were taken. Intra-operative venous sample was taken after careful dissection of the parathyroid glands and post operatively at 6 hours, 24 hours, and 48 hours. Samples were analyzed for PTH, ionized calcium, total calcium and albumin levels. Patients were followed up for a period of one year.

Results Nine patients (30%) developed clinical hypocalcaemia in this study. Out of thirty patients, PTH values were below normal in 14 (46.67%) intra-operatively, 13 (43.33%) at 6 hours, 16 (53.33%) at 24 hours, 12 (40.0%) at 48 hours postoperatively. PTH had a sensitivity of 100% in predicting hypocalcaemia in these entire time interval. Ionized calcium values were below normal in 10 (33.33%) patients intra operatively, 12 (40%) at 6 hours, 8 (26.67%) at 24 hours and 10 (30%) at 48 hours post-operatively. It had a sensitivity of 55.6%, 55.6%, 66.7% and 100% respectively in predicting hypocalcaemia at these time interval.

Conclusions Serum PTH proved to be a safe, convenient and easily available biomarker which can be measured to predict post-total thyroidectomy hypocalcaemia before the onset of serious symptoms.