Hypocalcemia Surveillance, Total Thyroidectomy — Intraoperative Care — Clinical Pathway: Inpatient and Outpatient Specialty Care

Thyroidectomy Calcium Management Clinical Pathway — Inpatient and Outpatient Specialty Care

Intraoperative Care

Trauma to the parathyroid glands during thyroidectomy can result in low parathyroid hormone (PTH) levels, leading to hypocalcemia. Intraoperative PTH assessment is a reliable measure to predict the development of hypocalcemia in children undergoing thyroidectomy. It allows for initiation of preventative therapy based on the child’s risk of developing hypocalcemia with the goal of preventing clinically significant hypocalcemia.

  • Place blood drawing IV
  • Obtain baseline laboratory studies with induction
    • Calcium, phosphorus, magnesium
  • Obtain and evaluate 3-4 samples of intraoperative PTH (ioPTH) assay
    • 20 mins after induction
    • After thyroid is removed
    • After the central neck dissection (if indicated/performed)
    • At time of closure

Normal Lab Levels by Age

Calcium

Age Reference Range (mg/dL)
Birth to 90 days 7.8-11.3
91-180 days 8.8-11.2
181-364 days 8.8-11.4
1-3 yrs 8.8-11.1
4-11 yrs 8.8-10.7
12-19 yrs 8.5-10.6
> 19 yrs 8.5-10.5

Phosphorus

Age Reference Range (mg/dL)
0 days to 11 mos 4.8-8.2
1-3 yrs 3.8-6.5
4-6 yrs 4.1-5.4
7-11 yrs 3.7-5.6
12-13 yrs 3.3-5.4
14-15 yrs 2.9-5.4
16-20 yrs 2.7-4.7
≥ 21 yrs 2.5-4.5

Magnesium

Age Reference Range (mg/dL)
0 days to 20 yrs 1.5-2.5
≥ 21 yrs 1.6-2.3