How to manage hypercalcemia in the Emergency Room (ER)?

From the Guidelines

Management of hypercalcemia of 3.43 mmol/L in the ER requires prompt intervention with hydration, bisphosphonates, and addressing the underlying cause, with zoledronic acid being the preferred bisphosphonate 1. To manage hypercalcemia, begin with aggressive IV normal saline at 200-300 mL/hour to promote calcium excretion and correct dehydration. Once adequately hydrated, administer IV bisphosphonates such as zoledronic acid 4 mg over 2-4 hours, as it is the preferred treatment for hypercalcemia according to the NCCN guidelines 1. For severe or symptomatic cases, consider calcitonin 4 IU/kg every 12 hours subcutaneously for rapid but temporary effect. Loop diuretics like furosemide 20-40 mg IV may be added after volume repletion to enhance calcium excretion. Some key points to consider when managing hypercalcemia include:

• Monitoring serum calcium, phosphate, magnesium, and renal function every 6-12 hours, along with continuous cardiac monitoring for arrhythmias.
• Investigating the underlying cause, commonly malignancy, primary hyperparathyroidism, or medication effects.
• Using denosumab, steroids, and/or calcitonin as alternative or additional treatments for hypercalcemia, as recommended by the NCCN guidelines 1. This approach works because saline increases renal calcium clearance, bisphosphonates inhibit bone resorption, and calcitonin rapidly decreases serum calcium levels while diagnostic workup and definitive treatment are initiated 1.

From the FDA Drug Label

1. 2 Hydration and Electrolyte Monitoring Patients with hypercalcemia of malignancy must be adequately rehydrated prior to administration of zoledronic acid injection. Loop diuretics should not be used until the patient is adequately rehydrated and should be used with caution in combination with zoledronic acid injection in order to avoid hypocalcemia Zoledronic acid injection should be used with caution with other nephrotoxic drugs. Standard hypercalcemia-related metabolic parameters, such as serum levels of calcium, phosphate, and magnesium, as well as serum creatinine, should be carefully monitored following initiation of therapy with zoledronic acid injection If hypocalcemia, hypophosphatemia, or hypomagnesemia occur, short-term supplemental therapy may be necessary.

The patient with a calcium level of 3.43 mmol/L is actually hypocalcemic, not hypercalcemic. Hypercalcemia management in the ER typically involves:

• Adequate rehydration
• Monitoring of electrolytes and renal function
• Avoidance of loop diuretics until the patient is adequately rehydrated
• Caution with nephrotoxic drugs However, since the patient is hypocalcemic, these measures may not be directly applicable. In the context of the provided drug labels, there is no direct guidance for managing hypocalcemia. Therefore, the management of this patient's hypocalcemia would require consideration of other factors and potentially other treatment options not addressed in the provided drug labels 2.

From the Research

Management of Hypercalcemia

To manage hypercalcemia of 3.43 in the ER, the following steps can be taken:

• Hydration with normal saline to help decrease calcium levels 3, 4
• Administration of intravenous bisphosphonates, such as zoledronic acid, to reduce serum calcium levels 3, 5, 4, 6, 7
• Loop diuretics may be required in individuals with renal insufficiency or heart failure to prevent fluid overload 4
• Calcitonin can be administered for the immediate short-term management of severe symptomatic hypercalcemia 4
• Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas) 5, 4

Treatment Options

The treatment options for hypercalcemia include:

• Zoledronic acid, which has been shown to be effective in reducing serum calcium levels in patients with severe hypercalcemia 3, 6, 7
• Pamidronate, which is also an effective treatment option for hypercalcemia 6
• Denosumab, which may be used in patients with kidney failure 5
• Dialysis, which is generally reserved for those with severe hypercalcemia complicated with kidney failure 5, 4

Monitoring and Follow-up

It is essential to monitor patients with hypercalcemia closely, as they are at risk of developing hypocalcemia after treatment with bisphosphonates 7

• Serum calcium levels should be monitored regularly to assess the effectiveness of treatment
• Patients should be followed up closely after discharge to ensure that their calcium levels remain within normal limits.