Initial management of hypocalcemia in adults without chronic kidney disease-mineral and bone disorder

IV: intravenous; D5W: 5% dextrose; NS: normal saline.

* Ionized calcium remains the gold standard for assessing calcium status, particularly if the diagnosis of hypocalcemia is in doubt due to hypoalbuminemia, atypical or absent symptoms, or a minimally reduced serum calcium concentration. If a laboratory known to measure ionized calcium reliably is not available, the total calcium should be corrected for any abnormalities in serum albumin, using a calcium correction formula.

¶ In patients with milder degrees of hypocalcemia or chronic hypocalcemia (due to hypoparathyroidism) who become unable to take or absorb oral supplements, as may occur after complex surgical procedures requiring prolonged recuperation, IV calcium may be needed to prevent acute hypocalcemia.

Δ Initially, IV calcium (1 or 2 g of calcium gluconate, equivalent to 90 or 180 mg elemental calcium, in 50 mL of D5W or NS) can be infused over 10 to 20 minutes. May repeat after 10 to 60 minutes if needed to resolve symptoms. Equivalent dose, SI units: 2.25 to 4.5 mmol calcium in 50 mL D5W or NS infused over 10 to 20 minutes.

• This should be followed by a slow infusion of calcium in patients with persistent hypocalcemia (eg, hypoparathyroidism, pancreatitis) – An IV solution containing 1 mg/mL of elemental calcium is prepared by adding 11 g of calcium gluconate (equivalent to 1000 mg elemental calcium) to normal saline or D5W to provide a final volume of 1000 mL.
• This solution is administered at an initial infusion rate of 50 mL/hour (equivalent to 50 mg elemental/hour).
• Equivalent dose, SI units – Add 24.75 mmol calcium to NS or D5W to provide a final volume of 1000 mL (final concentration of 0.025 mmol/mL) initiated at 50 mL per hour.

Refer to UpToDate content on treatment of hypocalcemia.

◊ Patients receiving digoxin should be monitored closely for acute digitalis toxicity, which can develop with calcium infusion.

§ Initially, 1 to 4 g of elemental calcium given as calcium carbonate or calcium citrate daily, in divided doses. Refer to UpToDate content on treatment of hypocalcemia.

¥ In addition to calcium, patients with vitamin D deficiency or hypoparathyroidism require vitamin D supplementation, which often permits a lower dose of calcium supplementation. Refer to UpToDate content on hypoparathyroidism and vitamin D deficiency.

‡ In patients with hypoparathyroidism, monitoring of urinary and serum calcium and serum phosphate is required weekly initially, until a stable serum calcium concentration (at the low end of the normal range) is reached. Thereafter, monitoring at 3- to 6-month intervals is sufficient. Refer to UpToDate content on hypoparathyroidism.