Dr Ed Wallitt
Podmedics - Founder
Video Duration: 10 minutes
Total plasma calcium level <2.2mmol/L
If due to renal failure, hypocalcaemia occurs due to reduced production of activated Vitamin D (leading to less calcium reabsorption in the small intestine) and increased retention of phosphate, by the kidneys.
If due to hypoparathyroidism, parathyroid glands produce less PTH, which leads to:
1) Reduced absorption of calcium by the kidneys
2) Reduced production of activated Vitamin D by the kidneys, leading to reduced absorption of calcium by the small intestine
Both of the above lead to a decrease in serum calcium levels.
Hypoparathyroidism, due to parathyroidectomy or autoimmune cause
Vitamin D deficiency, due to malnutrition or malabsorption (osteomalacia)
May be asymptomatic.
24 urinary calcium measurement
U&Es (to check if renal disease is present)
Serum PTH (if low in combination with low calcium --> suggests parathyroid cause; if PTH is high with low calcium --> suggests Vitamin D deficiency)
Serum parathyroid auto-antibodies
Oral Calcium supplements 5mmol every 6 hours
Acute treatment of tetany: 10ml of 10% Calcium Gluconate IV infusion over 10 minutes.
Maintenance therapy: 1,25 Dihydroxycholecalciferol (activated vitamin D) or 1-alpha-hydroxycholecalciferol (synthetic vitamin D/alphacalcidol)
Calcium level >2.6mmol/l.
Prevalence = 1:1000
Most common in elderly women
Most common cause is Primary Hyperparathyroidism, usually caused by a Parathyroid Adenoma or Hyperplasia.
This leads to excessive PTH production, which causes
1) increased calcium reabsorption in the kidney
2) increased activation of Vitamin D in the kidney, which in turn increases absorption of Calcium from small intestine
3) increased osteoclast activity, leading to bone resorption
All 3 lead to an increase in serum calcium levels
Primary Hyperparathyroidism (common!)
Secondary Bone Metastases (common!)
Excessive Vitamin D (rare
Asymptomatic in mild cases
"Bones, Stones, Groans and Psychic Moans"
Bone Pain (Osteitis Fibrosa Cystica)
Stones: Polyuria, Polydipsia (Nephrogenic Diabetes Insipidus), Nocturia, Renal Calculi, Chronic Kidney Disease
Groans: Abdominal pain, nausea, vomiting, constipation
Psychic moans: Confusion, Reduced GCS, Fatigue, Muscle Weaknes
24 hour urinary calcium measurement
Serum Calcium and Phosphate
Protein electrophoresis (if myeloma is suspected
If serum calcium > 3.5, treat as a medical emergency:
IV Fluids (Normal saline 4-6L over 24 hours and then 3-4L over several days)
Treatment of underlying cause
Steroids useful if due to sarcoidosis
Calcitonin, Phosphate therapy (hypercalcaemia associated with hypophospataemia
Surgical removal of parathyroid adenoma (if cause)
Surgical parathyroidectomy (if due to parathyroid hyperplasia)