Publication:

Timing of hypocalcemia after total or near total thyroidectomy: a prospective observational study

Background Hypocalcemia after thyroidectomy is the most common metabolic complication that prolongs the hospital stay. The aim of this study was to determine timing of hypocalcemia postoperatively and determine the safest day to discharge post-total or near-total thyroidectomy patients based on serum calcium level.

Methods From October 2012 to January 2017, the medical records of 117 consecutive patients who underwent a total or near-total, completion or redo thyroidectomy for benign and malignant thyroid diseases in two university hospitals were prospectively analyzed. The serum calcium was measured preoperatively, on the morning on the first, second, third and fourth postoperative days and the postoperative day on which hypocalcemia developed was identified.

Results Of the 117 patients who underwent a total or near thyroidectomy, 36 (30.7%) developed hypocalcemia, which was transient in 34 (29%) and permanent in two (1.7%) patients. The postoperative hypocalcemia was mild in 10 (8.5%) patients, and 26 (22.2%) patients developed significant postoperative hypocalcemia. Of the 36 patients who developed hypocalcemia postoperatively, the peak incidence of hypocalcemia (72.2%) was on the first postoperative day, and by the third day serum calcium measurement detected 97.3% of patients who developed hypocalcemia.

Conclusions Postoperative serial serum calcium levels may be useful for identifying patients suitable for early discharge following total/near total thyroid surgery in hospitals that lack the facilities. Hypocalcemia peaked on the first postoperative day. However, based on serum calcium levels alone, the third postoperative day is the crucial day for deciding whether to discharge the patients.