Is routine calcium supplementation necessary in patients undergoing total thyroidectomy plus neck dissection?

PURPOSE: Patients undergoing a total thyroidectomy plus neck dissection are at high risk of developing postoperative hypocalcemia. This study prospectively evaluated the possibility to identify factors that predict symptomatic hypocalcemia and the necessity of routine calcium supplements. METHODS: Sixty-five consecutive patients who underwent a total thyroidectomy plus neck dissection were included. Intact parathyroid hormone (iPTH), total serum calcium (sCa), serum phosphate (sPhos), and serum magnesium (sMg) levels were monitored and compared between the symptomatic hypocalcemic group ( group A) and the asymptomatic hypocalcemic group (group B). RESULTS: Asymptomatic and self-limiting hypocalcemia developed in 54 patients (81.5%; group B). Symptomatic hypocalcemia developed in 11 patients (18.5%; group A). They required calcium supplements. There were no significant differences in the iPTH and sMg levels between the two groups; the sCa level was significantly lower on postoperative days 1, 2, 3, and 5 in group A than in group B (P < 0.05); the sPhos level was significantly higher on postoperative days 2 and 3 in group A than in group B (P < 0.05). CONCLUSIONS: Symptomatic hypocalcemia develops within 3 days after surgery. An sCa level of less than 1.81 mmol/l can predict symptomatic hypocalcemia. Routine calcium supplements will not be necessary if the sCa level is higher than 1.81 mmol/l.