Hypocalcaemia

E83.5 + (E20.0-1/E20.8-9)

DESCRIPTION

Serum calcium (corrected for albumin) below the lower limit of normal.

Causes

  • Renal failure.
  • Hypoparathyroidism:
    • post neck surgery,
    • radiotherapy, or
    • idiopathic.
  • Vitamin D-related, (deficient intake, activation or action).
  • Hypomagnesaemia.
  • Malabsorption syndrome.

MEDICINE TREATMENT

Therapy is aimed at treating the underlying cause.

For acute hypocalcaemia with neurological problems and prolonged QT time on ECG:

  • Calcium gluconate 10%, infusion, 20 mL in 100 mL dextrose 5% given over 20 minutes, with ECG monitoring.

AND

  • Calcium gluconate 10%, infusion, 15 mg/kg (= wt [kg] x 1.7 mL) in 1000 mL sodium chloride 0.9% over 4 hours.

LoEIII [32]

For hypoparathyroidism:

  • Alfacalcidol, oral, 1–3 mcg daily.

AND

  • Calcium, elemental, oral, 500–1 500 mg daily in divided doses.

Correct magnesium deficiency if present.

Renal failure:

See Chronic Kidney Disease (CKD).

REFERRAL

  • If cause is uncertain.
  • If hypoparathyroidism suspected and PTH analysis required as above.