Endocrine Abstracts

JOINT3580

Background: Hypocalcaemia due to hypoparathyroidism is one of the most common complications of total thyroidectomy in the paediatric population. Early screening and postoperative monitoring are crucial to minimise long-term complications.

Aim: To evaluate the incidence of hypocalcaemia in paediatric patients submitted to total thyroidectomy, to identify associated risk factors, and to improve the screening protocol implemented at our centre since 2020.

Methods: Retrospective cohort study including all children submitted to total thyroidectomy, at our centre, from 1st January 2020 to 30th June 2024, without any conditions affecting calcium homeostasis and with a minimum follow-up period of 6 months after surgery. Demographic, clinical, surgical and laboratory data were collected from the patient’s medical records. A comparative statistical analysis was subsequently performed between children who developed hypocalcaemia and those who did not, using SPSS®, with a significance level set at P < 0. 05. Transient hypocalcaemia (<8. 5mg/dL) was defined as resolved within 6 months post-surgery.

Results: A total of 19 paediatric patients underwent total thyroidectomy, 68. 4% of whom were female, with a median age of 15. 2 years (IQR 3. 3). Indications for surgery included malignant neoplasm (n = 8), hyperthyroidism (n = 5), multinodular goitre (n = 3), and prophylactic thyroidectomy due to genetic risk of neoplasia (n = 3). The median hospital stay was 5 days (IQR 1. 25). Only 8 children had blood samples taken in the recovery room 60 minutes post-surgery, and only 8 received vitamin D supplementation at least one week prior (ranging from 10 to 435 days). Hypocalcaemia occurred in 68. 4% of the cases (n = 13), all within the first 24 hours post-surgery. Three patients developed paresthesia. Hypocalcaemia was transient in 9 cases (4 resolving during hospitalisation) and permanent in 4. Patients with hypocalcaemia had significantly lower preoperative vitamin D levels (19 vs 31 ng/mL, P = 0, 033) and a greater decrease in baseline calcium levels (-1. 3 vs -0. 8 mg/dL, P= 0, 046). ROC curve analysis to predict hypocalcaemia demonstrated an AUC of 0. 929 (P = 0. 040) for preoperative vitamin D (with an optimal cut-off using Youden Index of 25. 5 ng/mL) and 0. 788 (P = 0. 048) for calcium drop (cut-off of -1. 15 mg/dL).

Conclusion: The importance of screening and managing for post-total thyroidectomy hypocalcaemia is emphasised. This includes vitamin D supplementation for all children prior to elective surgery and monitoring calcium and PTH levels in the postoperative period, beginning in the recovery room, in order to identify at-risk patients early. We recommend multicentre studies to confirm these findings and enhance the intervention protocol.