A patient with cardiovascular disease has received one cartridge of 2% lidocaine, 1:100:000 epinephrine. How many milligrams of vasoconstrictor has this patient received? How many additional milligrams of vasoconstrictor can the patient receive before reaching MRD?
A) 0.018 mg received; 0.022 mg additional
B) 0.009 mg received; 0.391 mg additional
C) 0.36 mg received; 0.4 mg additional
D) 0.18 mg received; 0.22 mg additional

Question

Quizplus · Accepted Answer

1:100,000 epinephrine means that there is 1 mg of epinephrine in 100,000 mL of solution. One cartridge is 1.8 mL, so the patient received 1.8 mL x (1 mg / 100,000 mL) = 0.018 mg of epinephrine. The MRD for epinephrine is 0.04 mg, so the patient can receive an additional 0.04 mg - 0.018 mg = 0.022 mg of epinephrine.

A Patient with Cardiovascular Disease Has Received One Cartridge of 2