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NHS Lothian

Hypocalcaemia

Electrolyte Disturbance
NHS Lothian

Think

1. Is the patient unwell?

  • ABCDE approach 

2. Is the result a true value?

  • Could the sampling method have affected the result (if red bottle filled before brown bottle EDTA contamination can affect result)?
  • Is there a previous level?
  • Is the level corrected for albumin?

3. Does the patient have any symptoms or signs?

  • May indicate the significance and rapidity of electrolyte change
  • Tetany and carpopedal spasm. Positive Trousseau’s and Chvostek’s sign
  • Peri-oral and digital paraesthesiae
  • Seizure
  • ECG – prolonged QT

4. Are there culprit drugs? - consider stopping them

  • Cytotoxic drugs, large volume blood transfusion

5. Causes? - treat them

  • Parathyroidectomy or hypoparathyroid – check PTH and contact endocrinology if PTH low
  • Severe vitamin D deficiency, magnesium deficiency, pancreatitis, rhabdomyolysis

 

Treat

Severe (Ca2+ ≤1.9 mmol/L OR symptoms)

  • Ideally, cardiac monitor in situ but do NOT let the absence of this delay treatment
  • If symptomatic or ECG changes – 10 ml 10% calcium gluconate in 50 ml 5% dextrose over 10 minutes via large bore peripheral cannula. Repeat until asymptomatic
  • For all - 100 ml 10% calcium gluconate (10 vials) in 500ml 0.9% saline at 25 ml/hour 
  • Recheck Ca2+ level at end of infusion and repeat as needed

Mild/Moderate (Ca2+ >1.9 mmol/L AND asymptomatic)

  • Calcium Carbonate Calvive 1000 (1g/25mmol calcium) 2 tabs twice daily or Adcal chewable (600mg calcium) 2 tabs three times daily
  • *If immediately post thyroidectomy please follow appropriate surgical guideline and contact surgical team or endocrinology*
  • Of note - if vitamin D deficient will also need vitamin D replacement. If hypoparathyroid or severe renal impairment may need activated vitamin D (contact endocrinology or renal if advice needed).

 

Do I need to Escalate?

Seek Senior advice if concerns, and particularly if:

  • Severe hypocalcaemia
  • Please contact Endocrinology during working hours if concern regarding hypoparathyroidism

Cardiac Monitoring or HDU?

  • ECG monitoring is recommended during IV bolus administration in severe hypocalcaemia, particularly for patients with underlying cardiac disease, at risk of arrhythmias, or if the patient is on digoxin therapy
  • Cardiac monitoring needed in severe hypocalcaemia or if ECG changes ONLY if patient a candidate for escalation of care
  • Cardiac monitoring is required if the patient takes digoxin or who has a known arrhythmia