What are the manifestations and management of hypocalcemia?

Manifestations and Management of Hypocalcemia

Hypocalcemia manifests primarily as neuromuscular irritability, including tetany, seizures, paresthesias, muscle cramps, and cardiac arrhythmias, and requires prompt treatment with calcium supplementation to prevent serious complications or death. 1

Clinical Manifestations of Hypocalcemia

Neuromuscular Symptoms

• Tetany: Characterized by carpopedal spasm, muscle cramps, and hyperreflexia
• Seizures: Can occur at any age, especially during periods of biological stress
• Paresthesias: Particularly circumoral numbness and tingling in hands and feet
• Muscle cramps/spasms: May progress to tonic-clonic contractions
• Laryngospasm: Can cause acute respiratory distress in severe cases

Cardiovascular Manifestations

• Cardiac arrhythmias: Including prolongation of QT interval
• Decreased cardiac contractility: Leading to heart failure in severe cases

Neuropsychiatric Symptoms

• Fatigue and emotional irritability
• Confusion or memory loss
• Behavioral changes

Other Manifestations

• Abnormal involuntary movements
• Osteopenia/osteoporosis (with chronic hypocalcemia)

Management of Hypocalcemia

Acute Symptomatic Hypocalcemia

1. Immediate IV calcium administration:

   • Calcium gluconate 100-200 mg of elemental calcium IV
   • Monitor ECG during administration, especially in patients on cardiac glycosides 2
   • Administer slowly in small amounts if patient is on digoxin

2. Monitor calcium levels frequently (every 4 hours) until stabilized

3. Address precipitating factors:

   • Correct hypomagnesemia if present
   • Evaluate for underlying causes

Chronic Hypocalcemia Management

1. Daily oral calcium supplementation

   • Titrate dose based on serum calcium levels

2. Vitamin D supplementation

   • May require active metabolites (calcitriol) in severe cases
   • Consultation with endocrinologist recommended for severe hypocalcemia

3. Magnesium supplementation

   • Essential if hypomagnesemia is present, as it can impair parathyroid hormone function

4. Regular monitoring:

   • pH-corrected ionized calcium
   • Magnesium
   • Parathyroid hormone
   • Creatinine concentrations

Special Considerations

• Perioperative management: Targeted monitoring of calcium concentrations before and after surgery
• Pregnancy: Monitor closely as hypocalcemia can worsen during childbirth
• Acute illness: Increased risk of hypocalcemia during biological stress
• Medication interactions:
  • Avoid concomitant administration with cardiac glycosides
  • May reduce response to calcium channel blockers
  • Separate administration from medications that interfere with absorption

Cautions in Management

• Avoid overcorrection: Can lead to iatrogenic hypercalcemia, renal calculi, and renal failure
• Renal impairment: Start at lowest recommended dose and monitor closely
• Medication interactions: Calcium may interact with cardiac glycosides, calcium channel blockers, and drugs that cause hypercalcemia (vitamin D, vitamin A, thiazide diuretics) 2
• Aluminum content: Parenteral calcium products may contain aluminum, which can be toxic in premature neonates 2

Underlying Causes to Consider

• Hypoparathyroidism: Most common cause (often postsurgical)
• Vitamin D deficiency or disorders of vitamin D metabolism
• Magnesium deficiency: Can cause functional hypoparathyroidism
• 22q11.2 deletion syndrome: Associated with parathyroid dysfunction 1

Early recognition and appropriate management of hypocalcemia are essential to prevent serious complications and improve quality of life for affected individuals.