Calcium Chloride Dosing for Acute Hypocalcemia
For acute hypocalcemia, administer calcium chloride 10% at 20 mg/kg (0.2 mL/kg) IV/IO in children, or 5-10 mL (500-1000 mg) IV over 2-5 minutes in adults, with continuous cardiac monitoring. 1, 2
Preferred Agent and Rationale
- Calcium chloride is strongly preferred over calcium gluconate because it produces a more rapid increase in ionized calcium concentration, particularly critical in critically ill patients and those with liver dysfunction who cannot efficiently metabolize gluconate. 1, 3
- Calcium chloride 10% contains 270 mg of elemental calcium per 10 mL, compared to only 90 mg per 10 mL in calcium gluconate 10%, making it approximately 3 times more potent. 1, 3
Dosing by Population
Pediatric Dosing
- 20 mg/kg (0.2 mL/kg of 10% calcium chloride) IV/IO 1
- Give by slow push for cardiac arrest; infuse over 30-60 minutes for other indications 1
- Monitor heart rate continuously; stop injection if symptomatic bradycardia occurs 1
- Repeat dose as necessary for desired clinical effect 1
Adult Dosing
- 5-10 mL of 10% calcium chloride IV over 2-5 minutes for acute symptomatic hypocalcemia 3, 2
- The FDA-approved dosage for hypocalcemic disorders ranges from 200 mg to 1 g (2-10 mL) at intervals of 1 to 3 days, depending on response and serum ionized calcium levels 2
- Do not exceed 1 mL/min infusion rate 2
Administration Route and Monitoring
- Central venous access is strongly preferred to avoid severe skin and soft tissue injury from extravasation through peripheral IV lines 1, 3
- Continuous cardiac monitoring is mandatory during administration 1, 3
- If time permits, warm the solution to body temperature before administration 2
- Patient should remain recumbent for a short time following injection 2
Target Ionized Calcium Levels
- Maintain ionized calcium >0.9 mmol/L minimum to support cardiovascular function and coagulation 3
- Optimal target range is 1.15-1.36 mmol/L (normal range) 3
- Monitor ionized calcium levels every 4-6 hours initially until stable, then twice daily 3
- Adjust infusion rate based on serial ionized calcium measurements 3
Transition to Continuous Infusion
- For severe or refractory hypocalcemia, initial continuous infusion dosing should be 1-2 mg of elemental calcium per kilogram body weight per hour, adjusted to maintain ionized calcium in the normal range 3
- This translates to approximately 3.7-7.4 mL/kg/hour of 10% calcium chloride for continuous infusion 3
Critical Pitfalls to Avoid
- Do not mix calcium chloride with sodium bicarbonate - this causes precipitation 1, 3
- Do not mix with vasoactive amines 1
- Stop injection immediately if symptomatic bradycardia occurs 1, 2
- Correct magnesium deficiency first - hypocalcemia cannot be fully corrected without adequate magnesium, and hypomagnesemia is present in 28% of hypocalcemic ICU patients 3
- Be aware that standard coagulation tests may appear normal despite significant hypocalcemia-induced coagulopathy, as laboratory samples are citrated then recalcified before analysis 3
Special Clinical Contexts
Massive Transfusion/Trauma
- Hypocalcemia results from citrate-mediated chelation from blood products (especially FFP and platelets) 3
- Hypothermia, hypoperfusion, and hepatic insufficiency impair citrate metabolism, worsening hypocalcemia 3
- Colloid infusions (but not crystalloids) can independently contribute to hypocalcemia 3
Cardiac Arrest
- Calcium chloride is recommended only for documented hyperkalemia, hypocalcemia, hypermagnesemia, or calcium channel blocker toxicity 1
- Administer as slow bolus (push) during cardiac arrest 3
Tumor Lysis Syndrome
- Exercise extreme caution with calcium administration - only treat symptomatic patients and consider renal consultation if phosphate levels are elevated 3