Hypocalcemia

Trey Richardson

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Background

• Can be divided into low parathyroid hormone and high parathyroid hormone states

• Low PTH

  • Magnesium deficiency

  • Post-operative for parathyroidectomy

  • DiGeorge syndrome

  • Medications: Bisphosphonates, denosumab, aminoglycosides, gadolinium

  • Acidemia (Serum Ca is inversely proportional to pH)

  • Infiltrative disease: sarcoid, hemochromatosis, malignancies

  • Autoimmune hypoparathyroidism

  • CRRT (if using regional citrate anticoagulation)

• High PTH

  • Late-stage CKD

  • Hyperphosphatemia

  • Vitamin D deficiency

  • Pseudohypoparathyroidism/Parathyroid resistance

  • Consumption/deposition: Pancreatitis, rhabdomyolysis, some osteoblastic metastases

  • Sepsis or critical illness

Presentation

• Chvostek and Trousseau’s signs, laryngospasm, seizures, widened QRS and arrhythmias

• Hemodynamic instability

Evaluation

• Check PTH, albumin, iCal, VBG, Vitamin D

• Review medications for possible offenders

Management

• Under most circumstances there is no need to replace calcium. Instead, focus on correcting the underlying perturbation (e.g. acidemia, hypomagnesemia, treating pancreatitis, etc. )

• If hemodynamic instability, cardiac electrical instability, seizures then aggressive intravenous replacement is warranted.

  • Also consider preemptive repletion for patients requiring high-volume of blood transfusions (citrate in blood products can cause hypocalcemia)

  • 1 g of CaCl is equivalent to 3 grams of Ca Gluconate

• Avoid treatment in hyperphosphatemia, advanced CKD/ESRD, and rhabdomyolysis