If you administered two carpules of Lidocaine 1:100,000 how much Lidocaine did the patient receive?

If you administered two carpules of Lidocaine 1:100,000 how much Lidocaine did the patient receive?

• A. 72 mg Lidocaine
• B. 36 mg Lidocaine
• C. 144 mg Lidocaine
• D. 108 mg Lidocaine

Answer: (A)

Calculating how much lidocaine is given comes down to volume times concentration. A standard dental carpule holds about 1.8 mL, so two carpules equal 3.6 mL. A 1% lidocaine solution has 10 mg of lidocaine per milliliter. Multiply 3.6 mL by 10 mg/mL to get 36 mg of lidocaine delivered. The 1:100,000 epinephrine part affects vasoconstriction, not the lidocaine amount, so it doesn’t change the mg of lidocaine given.

Calculating how much lidocaine is given comes down to volume times concentration. A standard dental carpule holds about 1.8 mL, so two carpules equal 3.6 mL. A 1% lidocaine solution has 10 mg of lidocaine per milliliter. Multiply 3.6 mL by 10 mg/mL to get 36 mg of lidocaine delivered. The 1:100,000 epinephrine part affects vasoconstriction, not the lidocaine amount, so it doesn’t change the mg of lidocaine given.