The physician ordered lidocaine 2 g in 500 mL of D5W. It is to infuse at 1 mg/minute per infusion pump. How many hours will the IV run? Round to the nearest hour.
A) 30
B) 31
C) 32
D) 33

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, an equivalent is necessary. This is a multi-step problem. First, calculate milliliters per hour, then calculate number of hours. Begin by changing 1 mg/minute to 60 mg/hour (60 minutes = 1 hour) and converting 2 g to 2000 mg (1 mg = 1000 mg). Estimate the amount to give. Formula Method: 60 mg/hour ÷ 2000 mg *500 mL = 30,000/2000 = 15 mL/hour. Proportion (Ratios): 500 mL : 2000 mg :: x mL : 60 mg; 2000x = 30,000/2000 = 15 mL/hour. Proportion (Fractions): 500 mL/2000 mg = x mL/60 mg; 2000x = 30,000/2000 = 15 mL/hour. Use two conversion factors for dimensional analysis. Dimensional Analysis: 500 mL/2 g * 1 mg/1 minute * 1 g/1000 mg * 60 minutes/1 hour = 500 mL *1 * 60/2 * 1 * 1000 * 1 = 30,000/2000 hours = 15 mL/hour. To calculate the number of hours, use this formula: Number of milliliters/Number of milliliters per hour = Hours. Therefore, 500 mL ÷ 15 mL/hour = 33.33 hours. Round to the nearest hour: 33 hours.

The Physician Ordered Lidocaine 2 G in 500 ML of D5W