Postoperative parathyroid hormone (PTH) level may not be an effective indicator of the development of symptomatic hypocalcemia following thyroidectomy, according to research presented at the 87th Annual Meeting of the American Thyroid Association, held October 18-22, in Victoria, British Columbia, Canada.
Researchers from Rady Children’s Hospital in San Diego, California, conducted a retrospective review of pediatric patients (n=40) who underwent thyroidectomy to determine the risk for subsequent hypocalcemia.
“Many adult centers have used postoperative intact PTH level in the recovery room as a predictive indicator for postop[erative] hypocalcemia, with the aim of early discharge if the value is within normal range,” the researchers wrote. “However, very few studies have validated this approach in children.”
Following thyroidectomy, normal PTH level was found in 70% of patients; 30% of patients experienced transient hypoparathyroidism, and 5% had permanent hypoparathyroidism, which was identified at follow-up.
More than 45% of patients with normal PTH did not have transient hypocalcemia (PTH range: 27.5-65.5 pg/mL). Fifteen patients required inpatient calcium replacement (with or without calcitriol), and 11 were discharged with oral replacement.
In patients with normal PTH, a significant overlap was noted between patients who did or did not require calcium replacement.
The study investigators concluded that although PTH level <10 pg/mL is “highly sensitive” in predicting patients at high-risk for possible calcium level decline, “normal” PTH levels alone cannot always predict a “normal calcium level postoperatively, and cannot guide replacement or early discharge.”
Jiang W, Newfield R. The utility of intact parathyroid hormone level in predicting hypocalcemia after thyroidectomy in children. Presented at: 87th Annual Meeting of the American Thyroid Association; October 18-22, 2017; Victoria, BC, Canada. Poster 123.