We implemented a previously reported algorithm based on intra-postoperative PTH measurements with selected cut-off values, both to predict post-thyroidectomy hypoparathyroid hypocalcemia, and to guide postsurgical management. The objective of the study was to assess if this strategy was useful to reduce hypocalcemia, post-surgery calcium sampling and hospitalization length.

Sixty-six patients were included in the analysis. Based on their intra-operatory PTH determinations, patients were classified according to their post-surgical hypoparathyroidism risk and were either immediately treated with calcium and vitamin D1-25 supplementation (high-risk) or assigned to clinical control and routine calcium sampling (low-risk). The outcomes and overall results of these therapeutical approaches were compared with those of a control group, started on treatment when TCa levels dropped below normal.

In the high-risk subgroup (n=30) five patients showed hypocalcemia within the first 24 hours. Compared with the high-risk control subgroup, the incidence of hypocalcemia fell from 100% to 17% (p<0.001), and the median hospitalization length from 6 to 3 days (p<0.001).

In the low-risk subgroup (n=36) 28 patients remained normocalcemic with significantly less calcium sampling (p<0.001). Eight patients had hypocalcemia; 7 of them required neck dissection, which was the only risk factor related to post-surgical hypoparathyroidism (RR: 2.1 [CI 95% 1.4-3.1], P<0.001).

Compared to the control group, overall incidence of hypocalcemia was reduced by 58 %.

This approach improved patient's safety by reducing the occurrence of hypocalcemia and the length of hospitalization after thyroidectomy in pediatric patients. Preventive calcium supplementation seems to be more beneficial in patients undergoing neck dissection.

Inclusion Criteria:

• Patients who underwent total thyroidectomy between January 2014 and April 2020

Exclusion Criteria:

• Patients with known hyper or hypoparathyroidism, kidney failure, and those taking medications known to affect TCa, PTH, or vitamin D levels (octreotide, oral glucocorticoids, diuretics and antiepileptics), or any other condition that could interfere with calcium metabolism

All patients between 2 and 19 years of age who underwent total thyroidectomy at Hospital de Niños Ricardo Gutiérrez in Buenos Aires, Argentina between January 2014 and April 2020 were included. Exclusion criteria were patients with known hyper or hypoparathyroidism, kidney failure, and those taking medications known to affect TCa, PTH, or vitamin D levels (octreotide, oral glucocorticoids, diuretics and antiepileptics), or any other condition that could interfere with calcium metabolism.