Appropriate Use of IV Calcium

• IV calcium is used in replacement and/or cardiac stabilization. Overuse can occur

a. Patients with hyperkalemia and hypermagnesemia are commonly given calcium, but calcium is not a

definitive treatment for hyperkalemia or hypermagnesemia

• Ionized calcium versus serum calcium

a. Serum (total) calcium represents all calcium in the body, both free and protein bound. This is affected

by albumin stores in the body and can severely underestimate a patient’s true calcium level

b. Ionized (free) calcium represents active calcium in the body. Measuring ionized calcium should be

considered prior to treating hypocalcemia, especially in non-emergent cases

• IV calcium is currently on national drug shortage and consideration should be taken prior to ordering

Calcium Chloride

Calcium Gluconate

Mechanisms

Normalizes myocyte excitability by shifting threshold potential

Agonist at calcium channels to restore normal cardiac function in blockade

Formulations

100 mg/mL (10%) contains 1.36 mEq EC/mL

(3x higher than calcium gluconate)

100 mg/mL (10%) contain 0.465 mEq EC/mL.

Administration

IV push in emergent situations over 2-5 minutes.

Central line administration recommended

Slow IV push administration over 2 -5 minutes

May be given as continuous infusion for hypocalcemia

Adverse Effects

Arrythmias, bradycardia, cardiac arrest, syncope, tingling, necrosis of tissue (chloride > gluconate)

Drug Interactions

and warnings

Extravasation: Calcium is a vesicant, administration into tissue can cause necrosis

Not to be used when patient is in ventricular fibrillation in cardiac resuscitation

How supplied

Supplied at Grady as a 1 g/10 ml carpuject

syringe or vial only in code carts due to drug

shortage

Supplied at Grady as a 1g vial (100 mg/mL)

Clinical Pearls

Onset of action has been described as “immediate” but can take up to 5 minutes to start to have effects

The duration of action of calcium is 30 – 60 minutes

Indications for IV calcium

Use

Indications

Agents

Pearl

Acute/symptomatic

hypocalcemia

Acute symptoms and/or

ionized calcium < 3mg/dL

Moderate: Muscle

twitching, spasms, tingling,

numbness

Severe: cardiac

dysrhythmias, seizures

Other pearls found at:

www.pharmacyfriday.com

Hyperkalemia

Potassium > 5.5mg/dL +

EKG changes

Calcium gluconate

• 5-3g IVP over 2-5 minutes

Calcium chloride (cardiac arrest)

1g IVP over 2-5 minutes, repeat as

necessary

Calcium is used for heart

membrane stabilization, NOT

for potassium lowering effects.

Additional therapy must be

used in combination with

calcium to lower potassium

levels

Magnesium

overload

Severe cardiotoxicity/

cardiac arrest

Mild – moderate: nausea,

diarrhea, urinary retention,

lethargy, muscle weakness

Severe: hypotension,

cardiac abnormalities

Calcium gluconate

• 5-3g IVP over 2-5 minutes

Calcium chloride (cardiac arrest)

1g IVP over 2-5 minutes, repeat as

necessary

Hypermagnesemia can inhibit

parathyroid hormone

production leading to

hypocalcium, as well as

acting as a calcium channel

blocking agent at high doses

Current ACLS guidelines recommend against routine use of calcium in the treatment cardiac dysrhythmias

Calcium may be used off-label for calcium channel blocker or beta blocker overdoses on a case-by-case basis

Review of Evidence

Author,

Calcium does not directly lower potassium or magnesium. Additional therapies are needed to affect potassium

levels in combination with calcium administration

Routine use of calcium in cardiac dysrhythmias is not recommended

Ionized and serum calcium are not equal; considerations need to be taken when considering a patients’ true

calcium level

Oral replacement of calcium should be considered first line if patients are stable and/or chronic issue

Calcium chloride has a higher risk of extravasation and use should be restricted to cardiac arrest unless a

central line is established

Peacock WF, Frank Peacock W, Rafique Z, et al. Real World Evidence for Treatment of Hyperkalemia in the Emergency Department (REVEAL-ED): A Multicenter,

Prospective, Observational Study. The Journal of Emergency Medicine. 2018;55(6):741-750.

Parham WA, Mehdirad AA, Biermann KM, Fredman CS. Hyperkalemia revisited. Tex Heart Inst J. 2006; 33(1):40-47.

Link MS, Berkow LC, Kundenchuck PJ, et al. 2015 American Heart Associated guidelines updated for cardiopulmonary resuscitation and emergency

cardiovascular care. Part 7: adult advanced cardiovascular life support. Circulation. 2015;132:S444-64.

Byrnes MC, Huynh K, Helmer SD, Stevens C, Dort JM, Smith RS. A comparison of corrected serum calcium levels to ionized calcium levels among critically ill

surgical patients. Am J Surg. 2005;189(3):310-314.

High levels of potassium

can a decrease in

resting membrane

potential, causing the

membrane to become

partially depolarized

Calcium restores normal

myocyte excitability by

shifting the threshold

potential to a less

negative value

Normal difference of

resting potential and

threshold potential is

restored, thus stabilizing

the membrane