What is the composition of the push-dose epinephrine used in adult unstable bradycardia?

• A. 2 ml of 1:1000 Epi in 8 ml NS
• B. 5 ml of 1:100,000 Epi in 45 ml NS
• C. 0.5 ml of 1:1000 Epi in 9.5 ml NS
• D. 1 ml of 1:10,000 Epi in 9 ml NS

Answer: (D)

Push-dose epinephrine is used to rapidly support perfusion in adults with unstable bradycardia by delivering a small, fast-acting bolus that can be repeated as needed. The standard approach uses a dilution of a 1:10,000 epinephrine solution (0.1 mg per mL). By mixing 1 mL of this into 9 mL of normal saline, you get 10 mL of solution containing 0.1 mg total epinephrine, which is 0.01 mg per mL (10 micrograms per milliliter). A 1 mL dose therefore provides 10 micrograms of epinephrine, a dose that acts quickly and has a short duration, making it ideal for titrating toward stable rhythm and blood pressure while preparing longer-term therapy. Using a more concentrated solution would deliver far too large a dose and increase the risk of adverse effects, while other dilutions don’t reliably provide the intended 10 microgram bolus.