Calcium Abnormalities

Hypocalcaemia

Hypercalcaemia

ECG:

Investigations:

Clinical Features:

Management:

Causes:

Management:

ECG:

Clinical Features:

Causes:

Investigations:

Two biggest causes: malignancy/multiple myeloma AND primary hyperparathyroidism

Low PTH:

Elevated Vit D e.g. granulomatous diseases (e.g. sarcoidosis) and HIV

Hyperthyroidism

Paget's disease

Thiazide diruretics: Cl/Na pump at tubular side of DCT cells is blocked --> lower intracellular Na --> increased activity of Na/Ca exchanger at luminal end which iincreases intracellular Na and Ca in the blood

Malignancy: PTH related proteins are produced (paraneoplastic syndrome)

Addison's/steroid deficiency

Normal/high PTH

Primary/tertiary hyperparathyroidism

Familial hypercalcaemia

Renal stones

Abdominal groans

Psychic moans

Painful bones

Urinary thrones

Other: 50% asymptomatic, N&V, lethargy, anorexia, constipation, muscle weakness, decreased reflexes, HTN

Shortened QT interval

Bradycardia

Bloods: CMP, PTH, Vit D, UEC's, albumin

Tests to consider: bone scan, 24hr urine calcium (high in primary hyperparathyroidism), CXR (sarcoidosis)

  1. Increase GIT excretion: via glucocorticoids as they decrease calcium absorption
  1. Prevent bone resorption: via IV bisphosphonates (inhibit osteoclasts) OR calcitonin (opposite in action to PTH)
  1. Increase urinary excretion: loop diuretics and rehydration
  1. Avoid aggravating factors e.g. thiazide diuretics, dehydration, prolonged bed rest and high calcium diet
  1. Treat the underlying cause

Low PTH:

Increased PTH (secondary hyperparathyroidism):

Mental state changes: irritability, confusion, hallucinations, anxiety

Cataracts

Seizures

Parkinsonism

Brittle hair, patchy alopecia, brittle nails

Tetany

Paraestheisa

  1. Correct any hypomagnesaemia (must be corrected 1st)
  1. Calcium replacement

Bloods: CMP, PTH, Vit D, UEC's, albumin, lipase

Urinary calcium and magnesium

Vitamin D deficiency (inadequate UV exposure/renal failure/diet)

Parathyroid destruction: surgery (largest cause), radiation injury, autoimmune, tumour

Development parathyroid disorders: Di george syndrome

Hypomagnesaemia (causes include malabsorption, PPI's, and chronic ETOH) leads to PTH resistance

Low dietary intake

CKD (decreased GFR --> decreased PO4 clearance --> reduced free Ca2+ since it binds with PO4)

Other: acute severe illness: pancreatitis, rhabdo, tumour lysys syndrome; IV bisphosphonates in patients with untreated vit D deficiency

Dermatitis, eczema, hyperpigmentation

Prolonged QT interval

Preferred: IV calcium gluconate with ECG monitoring until sx resolve

IV Calcium chloride (not routine due to irritation)

  • 40% of circulating Ca is bound to Albumin