Perioperative determinants of transient hypocalcemia after pediatric total thyroidectomy

Purpose: We seek to identify risk factors associated with hypocalcemia after pediatric total thyroidectomy.

Methods: We retrospectively reviewed patients younger than 21years undergoing total thyroidectomy between January 2002 and January 2016. We defined hypocalcemia as any serum calcium <8mg/dl or ionized calcium <1.0mmol/L. Perioperative risk factors were identified through multivariate logistic regression.

Results: Ninety-one children underwent total thyroidectomy. The average age was 13.7±4.4years, and 77% were female. Transient hypocalcemia was diagnosed in 34% (n=31) of patients. There was one case of permanent hypoparathyroidism. Predictors of transient hypocalcemia included age (OR 0.87, 95% CI 0.8-0.97, p=0.01), lymphadenectomy (OR 6.6, 95% CI 1.7-31.6, p=0.01), and hyperthyroidism (OR 13.3, 95% CI 1.3-1849, p=0.03). Patients with malignancy undergoing central (OR 7.1, 95% CI 1.5-33.4, p=0.01) or central plus lateral lymphadenectomy (OR 6.33, 95% CI 1.0-40.1, p=0.05) had significantly increased risk for transient hypocalcemia. Malignancy, MEN2A/B, goiter, preoperative calcium supplementation, incidental parathyroid removal, and postoperative PTH <15pg/ml were not associated with transient hypocalcemia.

Conclusions: Younger age, hyperthyroidism, and concomitant lymphadenectomy during total thyroidectomy increase risk of developing transient hypocalcemia. Malignant cases with central or central plus lateral lymphadenectomy are also at increased risk. Aggressive perioperative management of hypocalcemia should be initiated in patients with these risk factors.

Level of evidence: 2b.