Confused student needs help.......

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I am taking Medical Math with GC at Western and I do not understand the formula for heparin doses. I need the formula explaind for how to find gtt/min and units/hr.

Here are the practice questions. This is NOT homework it is examples she gave in class that were not in the book and I do not understand why you put what where.

An IV of 10,000 units of heparin in 1000 mL of D5W infusing at 40 gtt/min using a 20 gtt/mL set. Calculate the units/hour.

Heparin 2500 units per hour using a 20 gtt/mL IV set, the solution strength is 50,000 units in 1000 mL of D5W. Calculate the gtt/min flow rate.

Thank You in advance.

Hi Heart~ I am sorry I cannot help with your question, I just had a question for you.. how is your class going? I am taking it this summer at Western also with GC, and just wondered how it is... thanks for any input. Good Luck.

Cathleen

Specializes in CICU.
I am taking Medical Math with GC at Western and I do not understand the formula for heparin doses. I need the formula explaind for how to find gtt/min and units/hr.

Here are the practice questions. This is NOT homework it is examples she gave in class that were not in the book and I do not understand why you put what where.

An IV of 10,000 units of heparin in 1000 mL of D5W infusing at 40 gtt/min using a 20 gtt/mL set. Calculate the units/hour.

Heparin 2500 units per hour using a 20 gtt/mL IV set, the solution strength is 50,000 units in 1000 mL of D5W. Calculate the gtt/min flow rate.

Thank You in advance.

I worked out your first example and got 1,200 Units per hour, see below:

Step 1. Infusion rate and tubing --> 40gtts/X mL = 20gtts / 1mL --> Solve for X and you know that you have 2 mL running per minute

Step 2. IV fluid and mL per minute --> 10,000 Units / 1,000 mL = X Units / 2 mL --> Solve for X and you know that you have 20 Units per minute

Step 3. 20 Units per minute x 60 minutes = 1,200 Units per hour

Is that the right answer?

Specializes in CICU.

OK - for the second problem I got 17 gtts / minute

Step 1. Figure how many mL you need to get 2,500 Units --> 50,000 Units / 1,000 mL = 2,500 Units / x mL --> Solve for X and you get 50mL per hour

Step 2. Plug the 50 mL per hour into the formula used to figure this --> 50mL / 1 hr X 1 hour / 60 minutes X 20gtts / 1mL --> 50 x 1 x 20 = 1000 and 1 x 60 x 1 = 60 --> 1000/60 = 16.6, round to 17 gtts per minute

That was a good refresher for me! Hope it helps you out - rather hard to explain on a message board.

Yes you were exactly right on both. Thank you and you did explain it well. I have printed it out and will refer to it while I study for my final. Thank You. Very much apperciated.

CatKar, My class is going well and GC explains stuff well. I was doing good so far with the formulas but for some reason could not wrap my head around how to put the folmula together or rather why it is put together the way it is. I took GC because she is an instructor in the nursing program so I figured she would be a good source of reference as to what type of math is required in the program. One piece of advice is do all the exercises in the book every week....it's good practice and it cements it in your brain.

Good luck, you'll be happy you took her.

For problem 2, this is the way I figure it. It is probably the same way as the person above me, but when they throw an "x" into it, it messes me all up.... :o)

Take "dose" over "on hand"

2500 units / 50000 units = 0.05 x 1000ml =50ml/hr (the units cancel each other out so you are left with "ml"

Then I take..... 50ml / 60min = 0.83 ml/min

Naturally then you want your drops per minute so you multiply

0.83ml/min by 20 gtt/ml = 16.6 (round up) 17gtt/min (again the ml's cancel each other out) so you are left with gtt and minute.

Anyway...that is the dummy version of doing things, but it has got me by so far.

Specializes in CICU.

Glad it helped, and good luck on your final! Keep practicing - if you are going into WCCCD's program you have a lot of math tests in your future :specs:

Specializes in CICU.
Anyway...that is the dummy version of doing things, but it has got me by so far.

I wouldn't say that is the dummy version at all - my instructor only taught us the version I used and it hasn't failed me yet... And, I don't have room in my brain for any more math formulas... ;)

Thanks for the info.. I just got my acceptance letter last Friday, and start in August.. and I am taking med math this summer to get it over with before nursing classes start, but math is not my strong point so I am a little nervous. I appreciate your advice, thank you.

Specializes in CICU.
Thanks for the info.. I just got my acceptance letter last Friday, and start in August.. and I am taking med math this summer to get it over with before nursing classes start, but math is not my strong point so I am a little nervous. I appreciate your advice, thank you.

Congrats on getting in! :yeah:You will be SO GLAD you took math early instead of during Foundations, I know I was.

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