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.