Hypercalcaemia

What is hypercalcaemia?

Hypercalcaemia refers to high levels of calcium in the blood above the normal range of 8.5-10.2 mg/dl.

Is hypercalcaemia a cause of concern?

Yes, it is a cause of concern as it can have many effects on the human body. The symptoms can be diverse and depend on blood calcium levels

Initially symptoms are nonspecific

  • Excess urine and thirst

  • Loss of appetite

  • Depression

  • Muscle weakness

  • Anorexia and nausea

  • Constipation

  • Fatigue

  • Heart problem

  • Pancreatitis

At higher levels

  • Abdominal pain

  • Vomiting

  • Dehydration

  • Lethargy

  • Heart problem

  • Pancreatitis

  • Osteoporosis

  • Coma

What are the causes of hypercalcaemia?

Primary hyperparathyroidism: Overactive parathyroid gland is the most common cause of hyperparathyroidism. It affects females more commonly than males and is more common in the age group of 50 – 60 years.

Other causes are:

  • Malignancy is the most common cause of hypercalcaemia.

  • Granulomatous conditions -such as sarcoidosis and tuberculosis

  • Endocrine conditions – such as thyrotoxicosis, phaeochromocytoma and primary adrenal insufficiency

  • Drugs- such as thiazide diuretics, vitamin D and vitamin A supplements

  • Familial- e.g. familial hypocalciuric hypercalcaemia

  • Tertiary hyperparathyroidism – Post Kidney transplant or chronic dialysis

  • Other: e.g. prolonged immobilization, milk-alkali syndrome, AIDS.

What are the investigations required?

a. Fasting blood sample for:

  1. Calcium

  2. Phosphorous

  3. Alkaline phosphatase

  4. PTH levels

  5. Vit D levels

  6. Renal function tests

b. 24 hour urine calcium levels

c. If the PTH is raised, technetium scan of the parathyroid gland is required to localize the adenoma together with an assessment of bone mineral density

What are the treatment options available?

Medical management
Treatment for acute hypercalcaemia should be initiated in hospital and will include

  • Increasing the circulating volume and hydration with saline

  • Once circulating volume is normal, addition of a loop diuretic e.g. furosemide

  • Biphosphonates such as pamidronate and zoledronic acid or salmon calcitonin may be used to reduce bone turnover

  • Plicamycin, gallium nitrate and prednisolone are also occasionally used in specialist settings

  • In severe cases haemodialysis may be effective

  • Asymptomatic patients with PTH mediated hypercalcaemia which doesn’t meet the recognised criteria for surgery may be treated conservatively with regular monitoring of bone density, renal function and serum and urinary calcium levels

  • Reduce patients intake of calcium

  • Mobilize a bed bound patient

Surgical management:
Indications

  • Serum calcium >15mg/dl

  • Urinary calcium excretion >400mg/day

  • Bone density reduced at any site to a T score <-2.5

  • Creatinine clearance reduced by 30%

  • Age >50years


Surgical procedure will include removal of the affected portion of the gland by a surgeon
.

Are there any complications that can arise after surgery?

Transient, mild hypocalcaemia is common after parathyroidectomy. The commonest cause of hypocalcaemia following parathyroidectomy remains transient hypo-parathyroidism due to suppression of the remaining parathyroid glands by preoperative hypercalcaemia. In fact surgeons are reassured by hypocalcaemia that develops transiently that the adenomatous gland has been removed.

In an entity called as hungry bone syndrome there is a rapid influx of calcium into the bones, which have been deprived of calcium, causing more prolonged hypocalcaemia. With the increased detection of hyperparathyroidism in the asymptomatic stage, primary hyperparathyroidism is being treated before the development of parathyroid bone disease and the incidence of hungry bone syndrome is falling.