Dosage Calculations!! PLease Help

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Hi everyone! I'm taking an online course that has me stressed out to the max! I need some guidance as to how to solve these:

1 g:15 mL expressed as a fraction is ___ g/100 mL.

Medication order: 750 mL of D5W with aminophylline 1 g at 0.9 mg/kg/hour

Patient Weight: 54 kg.

Calculate the flow rate in milliliters per hour.

Order: D5LR 1000 mL at 150 mL/hr. How many hours are required to administer the following fluid at the given rate?

I keep getting 6.7 hours but Im confused with the number..Im i suppose to round to the nearest whole hour?

Medication order: Loading dose, mix magnesium sulfate 20 g in 1000 mL D5W. Infuse 4 g over 30 minutes, then maintain at 1 g/hr. Maintain primary IV 1000 mL D5W at 60 mL/hr after magnesium sulfate loading dose.Available: Magnesium sulfate 50% in 10 mL vials

Calculate the secondary rate for the loading dose?

I followed steps in a tutorial..and keep getting 50? is this right?

Any help will be greatly appreciated!!

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Specializes in NICU.

Esme, Grntea, and the other enlightened ones will tell you the same thing, soon. Show your work for each problem and the answers you get. Then we will guide you towards the correct answers. We will not do your homework for you.

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Oh Well thank you for your input, Only been on this site for 4 hours..

I use the ratio method for the first problem

1G : 15 ML :: x : 100ML

15x=100 = 6.66 or 6.7 ?

15 15

Medication order: 750 mL of D5W with aminophylline 1 g at 0.9 mg/kg/hour

Patient Weight: 54 kg.

Calculate the flow rate in milliliters per hour.

54*0.9 mg per hr= 48.6 mg per hour

750/1000*60= 45ML per hour ?

]Order: D5LR 1000 mL at 150 mL/hr. How many hours are required to administer the following fluid at the given rate?

I keep getting 6.7 hours but Im confused with the number..Im i suppose to round to the nearest whole hour?

1000/150 = 6.66 or 6.7 hours

hoping to find someone who could give me a little more clarity on how to solve this ..i don't have a teacher to ask..and i found the short videos confusing, I was not looking for an answer but for advice.

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Specializes in Pedi.
Oh Well thank you for your input, Only been on this site for 4 hours..

I use the ratio method for the first problem

1G : 15 ML :: x : 100ML

15x=100 = 6.66 or 6.7 ?

Correct. I'd probably round to 6.67.

Medication order: 750 mL of D5W with aminophylline 1 g at 0.9 mg/kg/hour

Patient Weight: 54 kg.

Calculate the flow rate in milliliters per hour.

54*0.9 mg per hr= 48.6 mg per hour

750/1000*60= 45ML per hour ?

You need to pay attention to your units here. If you multiple 750 mL/1000 g x 60 min/hr it gives you mL x min over g x hr. Not what you want when what you're looking for is mL/hr. (I'm assuming that's where the 60 came from because I can't see anywhere else that it would have come from, but you don't need to do anything with minutes in this problem.)

You are correct in that you need to administer 48.6 mg/hr... so how many mL is that? There are 750 mL/1000 mg and you need to administer 48.6 mg/hr, right? So work from there and you will have your answer.

Order: D5LR 1000 mL at 150 mL/hr. How many hours are required to administer the following fluid at the given rate?

I keep getting 6.7 hours but Im confused with the number..Im i suppose to round to the nearest whole hour?

1000/150 = 6.66 or 6.7 hours

0.66 is 2/3, right? So you can figure out 2/3 of an hour in minutes easily and that's how I'd relay the answer.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
Oh Well thank you for your input, Only been on this site for 4 hours..

I use the ratio method for the first problem

1G : 15 ML :: x : 100ML

15x=100 = 6.66 or 6.7 ?

15 15

Medication order: 750 mL of D5W with aminophylline 1 g at 0.9 mg/kg/hour

Patient Weight: 54 kg.

Calculate the flow rate in milliliters per hour.

54*0.9 mg per hr= 48.6 mg per hour

750/1000*60= 45ML per hour ?

Order: D5LR 1000 mL at 150 mL/hr. How many hours are required to administer the following fluid at the given rate?

I keep getting 6.7 hours but Im confused with the number..Im i suppose to round to the nearest whole hour?

1000/150 = 6.66 or 6.7 hours

hoping to find someone who could give me a little more clarity on how to solve this ..i don't have a teacher to ask..and i found the short videos confusing, I was not looking for an answer but for advice.

We are always happy to help with homework......but we will not do it for you. I can tell by your post times it was only about 2 hours. Our goal is to help you become the best you can be.....seeing your work we can narrow it down to where you are making your mistakes so we can correct it.

Here are a couple of web site you might find helpful.

DosageHelp.com - Helping Nursing Students Learn Dosage Calculations

http://www.davesems.com/files/drug_dose_calculations.pdf

Know your conversions

The Short List 1 cup © = 8 ounces (oz)

1 dram (dr) = 60 grains (gr)

1 dram (fl dr) = 60 minims

1 gallon (gal) = 4 quarts (qt)

1 glass = 8 ounces (oz)

1 grain (gr) = 64.8 milligrams (mg)

1 gram (g) = 15.43 grains (gr)

1 inch (in) = 2.54 centimeters (cm)

1 kilogram (kg) = 2.2 pounds (lb)

1 liter (L) = 1.057 quarts (qt)

1 milliliter (mL) = 16.23 minims

1 minim = 1 drop (gt)

1 ounce (oz) = 2 tablespoons (tbsp)

1 ounce (oz) = 8 drams (dr)

1 ounce (fl oz) = 29.57 milliliters (mL)

1 pint (pt) = 16 ounces (oz)

1 pound (lb) = 16 ounces (oz)

1 quart (qt) = 0.946 liters (L)

1 quart (qt) = 2 pints (pt)

1 tablespoon (tbsp) = 3 teaspoons (tsp)

1 teacup = 6 ounces (oz)

1 teaspoon (tsp) = 4.93 mL

The Long list

1 central = 45,359 grams (g)

1 centimeter (cm) = 10 millimeters (mm)

1 cubic centimeter (cc) = 1 milliliter (mL)

1 cup © = 8 ounces (oz)

1 drachm = 3.55 milliliter (mL)

1 dram (dr) = 60 grains (gr)

1 dram (fl dr) = 60 minims

1 gallon (gal) = 4 quarts (qt)

1 gill = 4 ounces (oz)

1 glass = 8 ounces (oz)

1 grain (gr) = 64.8 milligrams (mg)

1 gram (g) = 1,000 milligrams (mg)

1 gram (g) = 1,000,000 micrograms (mcg)

1 gram (g) = 15.43 grains (gr)

1 hand = 4 inches (in)

1 inch (in) = 2.54 centimeters (cm)

1 kilogram (kg) = 1,000 grams (g)

1 kilogram (kg) = 2.2 pounds (lb)

1 liter (L) = 1000 milliliters (mL)

1 liter (L) = 1.057 quarts (qt)

1 meter (m) = 1,000 millimeters (mm)

1 meter (m) = 100 centimeters (cm)

1 milligram (mg) = 1,000 micrograms (mcg)

1 milliliter (mL) = 1 cubic centimeter (cc)

1 milliliter (mL) = 15 drops (gt)

1 milliliter (mL) = 16.23 minims

1 minim = 1 drop (gt)

1 ounce (fl oz) = 2 tablespoons (tbsp)

1 ounce (oz) = 20 pennyweights (dwt)

1 ounce (oz) = 24 scruples

1 ounce (oz) = 31.1 grams (g)

1 ounce (oz) = 480 grains (gr)

1 ounce (oz) = 8 drams (dr)

1 ounce, fluid (fl oz) = 29.57 milliliters (mL)

1 palm = 3 inches (in)

1 pennyweight (dwt) = 24 grains (gr)

1 pint (pt) = 16 ounces (oz)

1 pint (pt) = 4 gills

1 pound (lb) = 16 ounces (oz)

1 pound (lb) = 350 scruples

1 quart (qt) = 0.946 liters (L)

1 quart (qt) = 2 pints (pt)

1 scruple = 20 grains (gr)

1 stone = 0.14 cents

1 tablespoon (tbsp) = 3 teaspoons (tsp)

1 teacup = 6 ounces (oz)

1 teaspoon (tsp) = 60 drops (gtt)

1 teaspoon (tsp) = 4.93 mL

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Medication order: 75if mL of D5W with aminophylline 1 g at 0.9 mg/kg/hour

Patient Weight: 54 kg.

Calculate the flow rate in milliliters per hour.

I use the following formula to solve this type problem: (dose × weight × 60) ÷ concentration.

When using this formula it is important to remember to convert units so that you are using the same units throughout. I usually convert units to reflect what I am solving for. Since you are dosing mg/kg/hour and solving for flow rate in mL/hour, I would use mg/mL for concentration.

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