Calcium Replacement After Total Thyroidectomy

Rationale for Universal Calcium Supplementation

Transient hypocalcemia occurs in 5.4% to over 30% of patients after total thyroidectomy, depending on supplementation strategy, according to the National Comprehensive Cancer Network 1, 2, 3

Measure ionized calcium every 4-6 hours for the first 48-72 hours, then twice daily until stable, as recommended by the American Journal of Kidney Diseases 4, 5
If ionized calcium falls below 0.9 mmol/L (3.6 mg/dL) or corrected total calcium <7.2 mg/dL (1.80 mmol/L) despite oral supplementation, initiate intravenous calcium gluconate infusion at 1-2 mg elemental calcium per kilogram body weight per hour, according to the American Journal of Kidney Diseases 4, 5

Adjust infusion rate to maintain ionized calcium in normal range (1.15-1.36 mmol/L or 4.6-5.4 mg/dL) and gradually reduce infusion when ionized calcium stabilizes in normal range, as recommended by the American Journal of Kidney Diseases 4, 5

When oral intake is possible, transition to calcium carbonate 1-2 grams three times daily and calcitriol up to 2 μg/day as needed to maintain normal calcium levels, according to the American Journal of Kidney Diseases 4
Adjust doses based on calcium levels and symptoms, as recommended by the American Journal of Kidney Diseases 4