From the Guidelines
Post-operative hypocalcemia should be managed with calcium supplementation, with the approach depending on symptom severity and calcium levels, prioritizing the most recent and highest quality study available 1.
Management Approach
For mild asymptomatic hypocalcemia (serum calcium 7.5-8.5 mg/dL), oral calcium carbonate 1-2 g three to four times daily is recommended, as suggested by earlier guidelines 1.
- For moderate hypocalcemia or patients with mild symptoms like perioral numbness or tingling, add calcitriol 0.25-0.5 mcg twice daily to enhance calcium absorption.
- Severe symptomatic hypocalcemia (calcium <7.5 mg/dL) with tetany, seizures, or QT prolongation requires immediate IV calcium gluconate 1-2 g (10-20 mL of 10% solution) over 10-20 minutes, followed by a continuous infusion of 1-2 mg/kg/hr until oral therapy is established.
Considerations
- Magnesium levels should be checked and corrected if low, as hypomagnesemia can impair parathyroid hormone action, as generally understood in clinical practice.
- For patients after thyroidectomy or parathyroidectomy, prophylactic calcium supplementation may be initiated if PTH levels are low or undetectable, with consideration of the assay used for PTH measurement 1.
Monitoring and Adjustment
Treatment should continue until calcium levels stabilize, with gradual tapering of supplements while monitoring serum calcium.
- The underlying cause of hypocalcemia should be addressed, which is often transient parathyroid stunning after neck surgery but may become permanent in some cases, requiring long-term calcium and vitamin D supplementation.
- Clinical decisions should be based on PTH changes over time, using the same PTH assay for subsequent measurements to adequately evaluate the trend of PTH 1.
From the Research
Management of Post-Operative Hypocalcemia
- Post-operative hypocalcemia is a frequent complication after total thyroidectomy, and routine postoperative administration of vitamin D and calcium can reduce its incidence 2.
- The incidence of post-operative hypocalcemia can be decreased with the combined administration of both calcium and vitamin D supplements 2, 3.
- Treatment and management options for chronic hypocalcemia vary depending on the underlying disorder, and may include calcium and vitamin D supplementation, as well as replacement of parathyroid hormone (PTH) in hypoparathyroidism 4, 5.
- Intravenous calcium infusion is essential to raise calcium levels and resolve or minimize symptoms in the setting of acute hypocalcemia, while oral calcium and/or vitamin D supplementation is the most frequently used treatment for chronic hypocalcemia 5.
- Pre-operative treatment with calcium, vitamin D, or both calcium and vitamin D reduces the risk of post-operative hypocalcemia and should be considered in patients undergoing total thyroidectomy 6.
Prevention of Post-Operative Hypocalcemia
- Routine oral calcium and vitamin D supplementation may prevent hypocalcemic crisis, and its efficacy has been studied in patients undergoing thyroidectomy plus central neck dissection 3.
- The use of pre-operative calcium and vitamin D supplementation to prevent post-operative hypocalcemia in patients undergoing thyroidectomy has been shown to be effective in reducing the risk of post-operative hypocalcemia 6.
- The incidence of symptomatic and laboratory hypocalcemia can be significantly decreased with the use of routine postoperative supplementation with oral calcium and vitamin D 2, 3.
Treatment Options
- Calcium and vitamin D supplementation are commonly used to treat hypocalcemia, and the combined administration of both supplements can be more effective than either supplement alone 2, 3.
- Replacement of PTH with recombinant human PTH(1-84) has been approved for the treatment of hypoparathyroidism, and has been shown to be effective in correcting serum calcium levels and reducing the daily requirements of calcium and active vitamin D supplements 5.
- Long-acting recombinant human PTH may modify the management of chronic hypoparathyroidism in the future 5.