Electrolytes

Question 1

Causes hypocalcemia

Answer 1

• low Ca intake/malabsorption
• low Vit D
• CKD (impaired hydroxylation of 25OHD)
• pseudohypoparathyroidism
• a hydroxylase deficiency
• PTH deficiency- post neck surgery or inherited, diGeorge syndrome
• pseudohypocalcemia (low albumin) - ionised Ca normal OR alkalosis- increased binding to albumin, thus low ionised calcium
• transient neonatal hypocalcemia
• bisphosphonates
• acute pancreatitis
• maternal hypercalcemia –> suppression of PTH in fetus

Question 2

causes hypercalcemia

Answer 2

• high PTH (primary, tertiary)
  –> 1: parathyroid adenoma or carcinoma,
  –> 3: end stage CKD
• MEN syndromes
• high vit D, calcium intake
• thyrotoxicosis
• Williams syndrome
• acidosis –> increased ionised calcium (as less binds to albumin)
• thiazide diuretics
• many maligncies
• maternal hypocalcemia –> higher PTH to fetus)
• granulomatous disease

Question 3

Symptoms hypocalcemia

Answer 3

• Weakness
  
  • Fatigue
  • Muscle spasms, cramps
  • Tetany
  • Impaired memory, confusion
  • Ventricular arrythmias
  • Prolonged QT
  • Rickets
  • Osteomalacia
    
    • Parasthesia
    • Seizures

Question 4

Symptoms hypercalcemia

Answer 4

• Anorexia
  
  • Nausea/vomiting
  • Abdominal pian
  • Constipation
  • FTT
  • Thirst
  • Anxiety, depression, psychosis
  • Bone pain and fractures (if due to excessive bone resorption)
  • Kidney stones