The physician ordered 10 mg of subcutaneous lidocaine. The medication is available in a multidose vial labeled lidocaine 2%. How many milliliters should the nurse prepare?
A) 0.5
B) 1
C) 1.5
D) 2

Question

Quizplus · Accepted Answer

When solving any problem, first check that the order and the supply are in the same weight measure. For this problem, no equivalent is necessary. When a medication label states the strength of a drug as a percent, the percent means "parts per hundred." Therefore, lidocaine 2% means 2 g of lidocaine in 100 mL. Since 1 g is also equivalent to 1000 mg, you can interpret the solution as 2000 mg in 100 mL. Estimate the amount to give. Formula Method: 10 mg/2000 mg * 100 mL = 1000/2000 = 0.5 mL. Proportion (Ratios): 100 mL : 2000 mg :: x : 10 mg; 2000x = 1000/2000 = 0.5 mL. Proportion (Fractions): 100 mL/2000 mg * x/10 mg; 2000x = 1000/2000 = 0.5 mL. Use a conversion factor for dimensional analysis. Dimensional Analysis: 100 mL/2 g * 10 mg * 1 g/1000 mg = 100 mL * 10 * 1/2 * 1000 = 1000/2000 = 0.5 mL.

The Physician Ordered 10 Mg of Subcutaneous Lidocaine