Calculating IV Rate ml/hr for Drug Dosage based on Weight ProCalc Nsg 232 Welcome to the Yavapai College Verde Learning Center Tutorial for Calculating IV Rate in ml/hr for drug dosage based on weight

Calculating IV Rate ml/hr Example 1 1 gram of procainamide hydrochloride in dextrose 5% in water is to be infused at a rate of 70 mcg/kg/minute. The IV has a total volume of 500 ml. Your patient’s current weight is 48 lbs. At how many ml/hr will you infuse the IV? 70 mcg/kg/minute. To find the ml/hr: Step 1 – Write down the patient’s weight and convert Step 2 – Write down desired infusion dosage Step 3 – Write down the given IV strength (amt/volume) Step 4 – Convert as needed Step 5 – Reduce the units Step 6 – Perform the math In our first Example, (Read Slide) In Step one we write down patient weight. In this example our patient weight is 38 lbs. We will write this down as a fraction with a denominator of 1. Including a denominator will keep us organized when we perform the math. We look ahead to the infusion dosage and note that the dosage uses a weight in kg so we will need to convert our patient’s weight. To convert from pounds to kg we will use the equivalency of 2.2 lbs to 1 kg. We will write this as a fraction. Since the initial weight we wrote has lbs in the numerator we will write the conversion fraction with lbs in the denominator. Crossing off the matching pairs of unit labels leaves us with a unit label of kilogram which is what we want to find. Multiplying straight across the numerator we have 48 x 1 which is equal to 48. Multiplying straight across the denominator we have 1 x 2.2 which is equal to 2.2. Using long division or a calculator we find that 48 divided by 2.2 is equal to 21.8181. When converting to kg round your answer to the nearest tenth. Step 1 48 lbs 1 1 kg 2.2 lbs 48 x 1 kg 48 kg 21.8 kg 1 x = = = 1 x 2.2 2.2

Calculating IV Rate ml/hr Example 1 1 gram of procainamide hydrochloride in dextrose 5% in water is to be infused at a rate of 70 mcg/kg/minute. The IV has a total volume of 500 ml. Your patient’s current weight is 48 lbs. At how many ml/hr will you infuse the IV? To find the ml/hr: Step 1 – Write down the patient’s weight and convert Step 2 – Write down desired infusion dosage Step 3 – Write down the given IV strength (amt/volume) Step 4 – Convert as needed Step 5 – Reduce the units Step 6 – Perform the math In our first Example, (Read Slide) In Step one we write down patient weight. In this example our patient weight is 38 lbs. We will write this down as a fraction with a denominator of 1. Including a denominator will keep us organized when we perform the math. We look ahead to the infusion dosage and note that the dosage uses a weight in kg so we will need to convert our patient’s weight. To convert from pounds to kg we will use the equivalency of 2.2 lbs to 1 kg. We will write this as a fraction. Since the initial weight we wrote has lbs in the numerator we will write the conversion fraction with lbs in the denominator. In step 2, we write down the desired infusion dosage. In this example it is 70 mcg/kg/minute. In step 3 we will write down the given IV strength. We have 1 gram of procainamide in 500 ml. We will write this as a fraction since we will want to end up with ml/hr we will list the IV strength with ml in the numerator. In Step 4 we evaluate for any needed conversions. Since we want to find ml/hour we will need to convert from minutes to hours and we will need to convert from grams to mcg. We will use the fact that 60 minutes is = to 1 hour and 1 gram is equal to 1,000,000 mcg. We will write these equivalencies as fractions with minutes and grams in the numerators since we already have minutes and grams in the denominators. Step 5 we reduce the units. Crossing off matching pairs of unit labels in the numerator & denominator. We end up with ml per hour which is what we want to fine. In Step 6 we will perform the math. Multiplying straight across the numerator and then straight across the denominators. Step 1 Step 2 Step 3 Step 4 Step 6 21.8 kg 1 x 70 mcg 1 kg/min x 500 ml 1 gram 60 min 1 hour 1 gram 1000000 mcg x x 21.8 x 70 x500 x 60 ml = 1 x 1 x 1 x 1000000 hour Step 5

Calculating IV Rate ml/hr Example 1 1 gram of procainamide hydrochloride in dextrose 5% in water is to be infused at a rate of 70 mcg/kg/minute. The IV has a total volume of 500 ml. Your patient’s current weight is 48 lbs. At how many ml/hr will you infuse the IV? Step 6 21.8 x 70 x500 x 60 ml 45780000 ml = = = 46 ml/hr 1 x 1 x 1 x 1000000 hour 1000000 hr In the numerators we have 21.8 x 70 x 500 x 60 which equals 45780000 In the denominator we have 1 x 1 x 1 x 1,000,000 = 1,000,000 . Reducing 45,780,000 over 1,000,000 and rounding to the nearest whole ml we find that we will need to infuse the IV at the rate of 46ml/hour. Round ml/hr to the nearest whole number.

Calculating IV Rate ml/hr Example 2 200 milligrams of vibramycin in dextrose 5% in water is to be infused at a rate of 0.012 mg/kg/minute. The IV has a total volume of 220 ml. Your patient’s current weight is 130lbs. At how many ml/hr will you infuse the IV? 0.012 mg/kg/minute. To find the ml/hr: Step 1 – Write down the patient’s weight and convert Step 2 – Write down desired infusion dosage Step 3 – Write down the given IV strength (amt/volume) Step 4 – Convert to hours Step 5 – Reduce the units Step 6 – Perform the math In our second Example, (Read Slide) We use the same 6 steps to find the answer. In Step one we write down patient weight. In this example our patient weight is 130 lbs. We will write this down as a fraction with a denominator of 1. Including a denominator will keep us organized when we perform the math. We look ahead to the infusion dosage and note that the dosage uses a weight in kg so we will need to convert our patient’s weight. To convert from pounds to kg we will use the equivalency of 2.2 lbs to 1 kg. We will write this as a fraction. Since the initial weight we wrote has lbs in the numerator we will write the conversion fraction with lbs in the denominator. Multiplying across the numerator we have 130 x1 which equals 130. Multiplying across the denominator we have 2.2 x 1 which equals 2.2. Using a calculator or long division we find that 130/2.2 = 59.1 (When converting from lbs to kg. round your result to the nearest 10th.) Step 1 130 lbs 1 1 kg 2.2 lbs 130 kg x = = 59.1 kg 2.2

Calculating IV Rate ml/hr Example 2 200 milligrams of vibramycin in dextrose 5% in water is to be infused at a rate of 0.012 mg/kg/minute. The IV has a total volume of 220 ml. Your patient’s current weight is 130lbs. At how many ml/hr will you infuse the IV? To find the ml/hr: Step 1 – Write down the patient’s weight and convert Step 2 – Write down desired infusion dosage Step 3 – Write down the given IV strength (amt/volume) Step 4 – Convert as needed Step 5 – Reduce the units Step 6 – Perform the math In our second Example, (Read Slide) In Step one we write down patient weight. In this example our patient weight is 130 lbs. We will write this down as a fraction with a denominator of 1. Including a denominator will keep us organized when we perform the math. We look ahead to the infusion dosage and note that the dosage uses a weight in kg so we will need to convert our patient’s weight. To convert from pounds to kg we will use the equivalency of 2.2 lbs to 1 kg. We will write this as a fraction. Since the initial weight we wrote has lbs in the numerator we will write the conversion fraction with lbs in the denominator. Multiplying across the numerator we have 130 x1 which equals 130. Multiplying across the denominator we have 2.2 x 1 which equals 2.2. Using a calculator or long division we find that 130/2.2 = 59.1 (When converting from lbs to kg. round your result to the nearest 10th.) In step 2, we write down the desired infusion dosage. In this example it is 70 mcg/kg/minute. In step 3 we will write down the given IV strength. We have 1 gram of procainamide in 500 ml. We will write this as a fraction since we will want to end up with ml/hr we will list the IV strength with ml in the numerator. In Step 4 we will convert from minutes to hours. We will use the fact that 60 minutes is = to 1 hour. We will write this as a fraction with minutes in the numerator since we already have minutes in the denominator. Step 5 we reduce the units. Crossing off matching pairs of unit labels in the numerator & denominator. We end up with ml per hour which is what we want to fine. Step 1 Step 2 Step 3 Step 4 Step 6 59.1 kg 1 220 ml 200 mg x 0.012 mg 1 kg/min x x 60 min 1 hour 59.1 x 0.012 x 220 x 60 ml = 9361.44 ml = 1 x 1 x 200 x 1 hour 200 hr Step 5 = 47 ml/hr

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