Serological examination
Chvostek, hypocalcemia, fingertip or lip numbness, tetany
HYPOCALCEMIA, HYPOPARATHYROIDISM
All patients were examined for serum calcium level (normal reference range 2.20-2.65 mmol/L) and parathyroid hormone (PTH) level (normal reference range 12-88 pg/mL) before surgery. These indexes were re-checked on the first postoperative day. The occurrence of symptomatic hypocalcemia (fingertip or lip numbness, positive Chvostek sign, or tetany) was also recorded. If the symptoms were obvious or the PTH level was below the lower limit of normal, the minimum dose of oral and intravenous calcium supplementation was used in patients until they had no symptoms of hypocalcemia. If any patient had temporary hypoparathyroidism, their PTH levels were re-checked on the 3rd and 7th postoperative days and during monthly outpatient follow-up until they returned to the normal range.