The role of early postoperative parathyroid hormone level after total thyroidectomy in prediction of hypocalcemia.

Background: Estimation of parathyroid hormone (PTH) after thyroid surgery helps to predict the development of hypocalcemia and allows early intervention and management with oral calcium and/or vitamin D supplementation in the postoperative period.

Patients And Methods: This retrospective study included 57 patients who underwent total or completion thyroidectomy within 4 years. Measurement of serum PTH level was done 3 h after surgery for its change and prediction of hypocalcemia.

Results: The mean age was 42.11 years, females constituted 46 patients (80.7%), the main surgical procedure was total thyroidectomy in 51 patients (89.5%), and the main cause for surgery was multinodular goiter in 33 patients (57.8%). Three hours after surgery 47 patients (82.5%) had serum PTH levels of >10 pg/ml (mean 28.06) and 44 patients (77.2%) had normal serum calcium (mean 8.66). Most of these 47 patients (82.46%) didn't require postoperative supplementation, while from other 10 patients (17.5%) with serum PTH level of <10 pg/ml, 7 patients (12.28%) required both oral calcium and vitamin D, and 3 patients (5.26%) required only oral vitamin D.There was a significant correlation between the 3-h postoperative PTH level and hypocalcemia (P-value 0.000). The type of pathology had no significant association with lowserum PTH level after surgery (P-value 0.166).

Conclusion: PTH measurements at 3 h after total thyroidectomy is an accurate predictor for the development of hypocalcemia and allows starting early calcium and/or vitamin D supplements for the asymptotic patients with PTH level of less than 10 pg/ml, which is considered a high-risk group. Also it facilitates a safe and early (2nd day post operative) discharge of those patients with serum PTH levels greater than 10 pg/ml without any supplements.Further studies are needed to compare the result of early serum PTH level with the day one serum PTH level after total thyroidectomy to predict hypocalcemia.