“Patient X, presented with fitting episode. Upon arrival at ED, blood taken shows serum calcium 1.4, albumin 40″

Introduction

• Normal range of serum calcium: 2.1 – 2.65 mmol/L
• Fast correction is indicated if the patient is symptomatic or if hypocalcaemia is severe e.g. <1.8 mmol/L

Correction of severe / acute symptomatic hypocalcaemia:

Fast correction, followed by infusion

(i) Fast correction

• IV calcium gluconate 10% 10 mL over 10 minutes

(ii) IV infusion of Calcium gluconate 10%

• Rate: 1 mg elemental calcium/kg/hr // 0.5 – 2 mg/kg/hr
• Dilute 50 mL (i.e. 5 vials) of Calcium gluconate 10% into 400 mL of D5% or normal saline -> final volume = 450 mL -> 1mg/mL of elemental calcium solution

• For example, a 70 kg patient requiring 1 mg/kg/hr of elemental calcium will need 70 mL of infusion per hour

• Correct hypomagnesaemia if present.
• Treat underlying cause

Writing the instruction:

1. Add 50 mL of Calcium gluconate 10% into 400 mL normal saline. Total volume = 450 mL = 1 mg/mL calcium.
2. Run diluted IVI calcium gluconate 10% at 50 mL/hr*
3. Repeat serum calcium after fast correction
4. Monitor serum calcium and albumin levels 4 -6 hourly
5. Aim corrected calcium level 2 – 2.25 mmol/L
6. Correct hypomagnesaemia if present

[*If the patient’s weight is 70 kg, 50 mL/hr = 0.71 mg/kg/hr (within the range of elemental calcium 0.5 – 1 mg/kg/hr)]

[*If the patient has fluid restriction, e.g. ESRF consider to give half of the standard infusion e.g. 25 mL/hr]

Further reading:

• Sarawak Handbook of Medical Emergencies 4th ED (7.16)