How can hypocalcemia, with an adjusted calcium level of 1.80, be corrected?

From the Guidelines

To correct a low adjusted calcium level of 1.80 mmol/L, immediate treatment with intravenous calcium is recommended, followed by oral calcium supplementation and calcitriol to enhance calcium absorption. The patient's condition requires prompt attention to prevent complications such as tetany, seizures, and cardiac arrhythmias that can occur with critically low calcium levels 1.

Key Considerations

• Administer calcium gluconate 10% solution, 10-20 mL (1-2 ampules) IV over 10-20 minutes, followed by a continuous infusion of calcium gluconate at 1-2 mg/kg/hour for acute management.
• Once stabilized, oral calcium supplementation should be initiated with calcium carbonate 1000-2000 mg elemental calcium daily in divided doses.
• Adding calcitriol (active vitamin D) at 0.25-0.5 mcg daily will enhance calcium absorption, as suggested by guidelines for managing hypocalcemia in patients with 22q11.2 deletion syndrome 1.

Monitoring and Underlying Causes

• Monitor calcium levels every 4-6 hours initially, then daily until stable.
• Underlying causes must be investigated, including vitamin D deficiency, hypoparathyroidism, renal failure, or medication effects.
• Magnesium levels should also be checked and corrected if low, as hypomagnesemia can impair parathyroid hormone function, and magnesium supplementation is indicated for those with hypomagnesemia 1.

Prevention of Complications

• Patients may require ECG monitoring during correction due to risk of cardiac arrhythmias with severe hypocalcemia.
• The goal is to gradually normalize calcium levels while preventing complications like tetany, seizures, and cardiac arrhythmias that can occur with critically low calcium levels, and caution is advised with respect to over-correction, which can result in iatrogenic hypercalcemia, renal calculi, and renal failure 1.

From the Research

Correcting Adjusted Calcium Levels

The patient has an adjusted calcium level of 1.80, which is considered low. To correct this, the following options can be considered:

• Intravenous calcium infusion to raise calcium levels and resolve or minimize symptoms in the setting of acute hypocalcemia 2
• Oral calcium and/or vitamin D supplementation, which is the most frequently used treatment for chronic hypocalcemia 2
• Providing the missing hormone with the use of recombinant human parathyroid hormone (rhPTH) in patients with hypoparathyroidism, which has been shown to be effective in correcting serum calcium levels and reducing the daily requirements of calcium and active vitamin D supplements 2

Considerations for Correction

When correcting adjusted calcium levels, it is essential to consider the underlying disorder causing the hypocalcemia. For example:

• In patients with hypoparathyroidism, calcium and vitamin D supplementation must be carefully titrated to avoid symptoms of hypocalcemia while keeping serum calcium in the low-normal range to minimize hypercalciuria, which can lead to renal dysfunction 3
• In patients with disorders that disrupt the metabolism of vitamin D, treatment may involve addressing the underlying vitamin D deficiency 3

Measurement of Calcium Levels

The measurement of calcium levels can be affected by various factors, including:

• Serum albumin concentration, which can impact the accuracy of total calcium measurements 4, 5, 6
• The use of adjustment formulas, which may not always provide an accurate representation of ionized calcium levels 5, 6
• The presence of hypoalbuminemia, which can increase the risk of misclassification of true calcium status 5, 6