Hypocalcaemia

Question 1

Define hypocalcaemia

Answer 1

When calcium levels are lower than 2.5mmol/L

Question 2

What are the main causes of hypocalcaemia

Answer 2

1.)

Question 3

What are the main causes of hypocalcaemia

Answer 3

• Low magnesium: reduces release of PTH + increases PTH resistance
• Renal insufficiency: can’t activate inactive vitamin D
  -Low vitamin D: from limited dietary intake
• Low PTH:
  causes from notes:
  Vitamin D deficiency – presents with low phosphate
  Poor calcium uptake in the GI tract and decreased absorption in kidneys
  Leads to osteomalacia
  50% of people are vitamin D deficient
  Hypoparathyroidism – presents with high phosphate
  Secondary - post parathyroidectomy or thyroidectomy
  Acute pancreatitis – presents with low phosphate
  Osteomalacia – presents with low phosphate
  Soft bones partially due to low calcium and vitamin D deficiency
  Serum calcium low because Ca2+ can’t be absorbed from blood
  Parathyroid gland recognises this and produces PTH to suck calcium from kidneys and resorb bone
  Chronic Kidney Disease – presents with high phosphate
  Causes poor uptake of calcium in the kidneys
  Caused by inadequate production of active vitamin D and renal phosphate retention 🡪 microprecipitation of calcium phosphate in tissues
  Pseudohypoparathyroidism – resistance to PTH due to a mutation with Gz subunit on the parathyroid gland
  Drugs
  Calcitonin – decreases Ca2+ and phosphate
  Bisphosphonates – reduce osteoclast activity resulting in reduced Ca2+

Question 4

What are the investigations and diagnosis for hypocalcaemia

Answer 4

1. ) Chtosks sign: tap the facial nerve and you should see a twitch (only has 29% sensitivity)
2. ) Tvosky: cause mild hypoxia in hand and you get seizure of hand (has 94% sensitivity)

Question 5

What are the main signs/symptoms of hypocalcaemia

Answer 5

Symptoms:

• Spasms: hands + feet/larynx/premature labour (uterine contractions)
• Peripheral paraesthesia
• Anxious
• Seizure
• Muscle tone increases

Signs:

• Convulsion
• Arrhythmias
• Tetany
• Chvokstek’s sign: tapping of facial nerve near the parotid gland causes the ipsilateral facial muscles to twitch
• Trousseau’s sign: carpopedal spasm is induced by inflating a sphygmomanometer cuff to 20mmGh above systolic BP

Question 6

What are the investigations and diagnosis for hypocalcaemia

Answer 6

1. ) ECG: long QT interval

2. ) Bloods

Question 7

What are the treatment and management options for hypocalcaemia

Answer 7

• Mild: adcal supplement (calcium carbonate) or cholecalciferol
• Severe: calcium gluconate via IV