Hypocalcemia

Hypocalcemia

 

Hypocalcemia may be noted either acutely or chronically in hospitalized patients and outpatients.

Epidemiology

  • Prevalence – occurs in 12-80% of critically ill patients

Etiology

  • Acute hypocalcemia – intensive care unit patients (acute pancreatitis, sepsis)
  • Hypoparathyroidism 
    • Autoimmune hypoparathyroidism
      • Associated with polyglandular syndrome 1
      • Symptoms – chronic mucocutaneous candidiasis, alopecia and vitiligo
      • Autosomal recessive inheritance
    • Acquired
      • Surgical removal of parathyroids
      • Radiation-induced parathyroid destruction
    • Pseudohypoparathyroidism
      • Resistance to parathyroid hormone (PTH)
    • DiGeorge and velocardiofacial syndrome
      • Rare congenital disorder
      • Symptoms – cardiac, facial, thymic and thyroid abnormalities
        • Severe early childhood infections
      • Learning disorders
      • Genetics – rearrangements on chromosome 22
  • Vitamin deficiency
    • Malabsorption
    • Inadequate diet/sunlight
  • Magnesium deficiency
    • Malabsorption
    • Inadequate diet
    • Alcoholism

Pathophysiology

  • Serum calcium concentration kept within a narrow physiologic range
  • Control of calcium by parathyroid hormone, vitamin D (1,25), calcium and phosphate

Clinical Presentation

  • Acute
    • Neuromuscular – tetany, paresthesias, muscle spasms (Chvostek and Trousseau signs)
    • Neuropsychiatric – anxiety, hallucinations, confusion
    • Cardiovascular – bradycardia, ventricular arrhythmias, cardiac collapse
  • Chronic
    • Neuropsychiatric – cognitive deficits, extrapyramidal symptoms
    • Dermatologic – dermatitis, dry skin
    • Dental – enamel hypoplasia
    • Ophthalmologic – cataracts

Diagnosis

  • Indications for testing
    • Suspect when symptoms occur and serum calcium is low
  • Laboratory testing
    • Repeat serum ionized calcium testing
    • Intact PTH

Treatment

  • Treat according to etiology
  • Calcium (may require intravenous calcium depending on calcium level) and vitamin D analogues

See Also