The physician ordered 50 mg of nitroglycerin in 250 mL of D5W. It is to infuse at 10 mcg/minute per infusion pump. What is the correct IV rate in milliliters per hour? Round to the nearest whole number.
A) 2
B) 3
C) 4
D) 5

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, reduce the numbers in the standard solution to milligrams per milliliter: 50 mg/250 mL = 0.2 mg/1 mL. Next, change milligrams to micrograms: 0.2 mg/mL = 200 mcg/mL (1 mg = 1000 mcg). Divide by 60 to get micrograms per minute: 200 mcg/60 minutes = 3.33 mcg/minute. Estimate the amount to give. Round to the nearest whole number. Formula Method: 10 mcg/minute ÷ 3.33 mcg/minute * 1 mL = 3 mL/hour. Proportion (Ratios): 1 mL : 3.33 mcg :: x mL : 10 mcg; 3.33x = 10 mcg/3.33 = 3 mL/hour. Proportion (Fractions): 1 mL/3.33 mcg = x mL/10 mcg; 3.33x = 10 mcg/3.33 = 3 mL/hour. Use two conversion factors for dimensional analysis. Dimensional Analysis: 250 mL/50 mg *10 mcg/minute ÷ 1 minute * 60 minutes/1 hour * 1 mg/1000 mcg = 250 mL *60 * 1/50 *1 * 1 hour * 1000 = 150,000/50,000 = 3 mL/hour.

The Physician Ordered 50 Mg of Nitroglycerin in 250 ML