Pharmacy Guidelines 3

PHARMACY GUIDELINES Adult Intravenous Calcium Replacement Therapy General Information: •

Reference Calcium Levels: 1. Total serum calcium: 2.1-2.55 mmol/L or 8.42-10.22 mg/dL 2. Ionized serum calcium: 1.19-1.31 mmol/L or 4.76-5.24 mg/dL

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Corrected Calcium According to Albumin Levels: 1. Corrected Calcium (mg/dL)= Measured Calcium (mg/dL) + 0.8 (4-Serum Albumin[g/dL]) 2. Corrected Calcium (mmol/L)= Measured Calcium (mmol/L) + 0.02 (40Serum Albumin[g/L])

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Formulary IV Calcium Preparations: 1 mEq of Calcium = 0.5 mmol Calcium (mg/dL) x 0.25 = Calcium (mmol/L)

Salt Calcium Chloride 10% (100 mg/mL) Calcium Gluconate 10% (100 mg/mL)

Elemental Calcium 27 mg Calcium/mL

mmol Calcium/mL 0.68 mmol

9 mg Calcium/mL

0.23 mmol

mEq Calcium/mL 1.36 mEq 0.46 mEq

Hypocalcaemia: Corrected serum calcium < 1.75 mmol/L or ionized serum calcium of less than 1.025 mmol/L. Hypocalcaemia could be asymptomatic (requires maintenance calcium through oral supplementation) or symptomatic (Tetany, ECG changes, Convulsions) which requires bolus replacement by IV calcium: Intravenous Calcium Replacement (Bolus Dose): • By default, if the calcium salt for infusion is not mentioned in the order, calcium gluconate will be used as it causes less phlebitis (Calcium chloride is acidifying; it should not be used when acidosis coincides with hypocalcaemia) Ionized Serum Calcium 0.8-1 mmol/L (Mild/Symptomatic) 0.6-0.79 mmol/L (Moderate) < 0.59 mmol/L (Severe)

Replacement Guidelines 2 g (4.6 mmol) calcium gluconate IV 3 g (6.9 mmol) calcium gluconate IV 4 g (9.2 mmol) calcium gluconate IV

Dilution & Infusion Rate: •

1-2 g (2.3-4.6 mmol) of calcium gluconate to be diluted in 50 ml dextrose 5% or 0.9% sodium chloride and infused over 30 minutes. • 3-4 g (6.9-9.2 mmol) of calcium gluconate to be diluted in 100 ml dextrose 5% or 0.9% sodium chloride and infused over 60 minutes. • Maximum allowable concentration: 0.23 mmol/mL (100 mg/mL) i.e. 5 g in 50 mL diluent • Maximum allowable rate: 0.35 mmol/min (150 mg/min) Continuous Infusion: •

0.0125-0.05 mmol/kg/hr reduced to 0.0007-0.0125 mmol/kg/hr for further infusions. Maximum total daily dose 34.5 mmol (15 g of calcium gluconate 10%)

Precautions: • •

Calcium salts are irritating to tissues, especially calcium chloride. Close observation is essential during infusion of calcium via a peripheral vein in order to detect any extravasation at the earliest possible moment. Intravenous calcium should not be administered to patients receiving digoxin. The inotropic and toxic effects of the two drugs are synergistic and arrhythmias may occur if they are given together.

Monitoring: • • • •

Check for extravasation if calcium is given through a peripheral line. Check patient's heart rate; calcium may cause bradycardia. Check serum magnesium level; hypomagnesaemia is a cause of hypocalcemia due to end organ resistance to parathyroid hormone and possibly impaired PTH secretion. Check serum phosphate level; hyperphosphatemia can induce hypocalcemia due to metastatic calcification of calcium phosphate in the soft tissues and lungs. (usually associated with renal disease)

References: 1. Guidelines for Calcium Replacement, King Faisal Specialist Hospital & Research Center 2. Hypocalcaemia: Treatment Guidelines, Kingston General Hospital, Ontario-Canada; http://www.kgh.on.ca/pharmacy/Guidelines.pdf 3. Guidelines for Calcium Replacement in Adults, Medical University of South Carolina Pharmacy Services: www.musc.edu/pharmacyservices/medusepol/Adult_Calcium_Guidelines.pdf 4. Calcium Administration Guidelines, Massachusetts General Hospital, Department of Pharmacy & Department of Nursing Critical Care: http://www.massgeneral.org/pharmacy/icu%20Guidelines/calcium.htm 5. Calcium Chloride & Calcium Gluconate-IV Dilution, GlobalRPh Inc. http://www.globalrph.com/calcium_dilution.htm 6. Electrolyte Replacement Protocol, Oregon Health & Science University www.ohsu.edu/medicine/residency/handouts/pharmpearls/Nephrology/ElectrolyteRe placementProtocol.pdf 7. Adult Electrolyte Replacement Protocols; www.surgicalcriticalcare.net/Guidelines/electrolyte_replacement.pdf 8. Monitored Unit Electrolyte Replacement Protocols; www.emcrit.org/misc/electrolyte_replacement.pdf 9. Electrolyte Infusion Guidelines at University of Kentucky Hospital; http://www.hosp.uky.edu/Pharmacy/formulary/criteria/electrolyte.htm