med math help

Jill2Shay · Sep 2, 2013

Did your instructors not teach you any formulas for this?

yayi4, ADN, BSN · Sep 2, 2013

Did your instructors not teach you any formulas for this?

no, its actually the first time im seeing questions like the 1st and second one.

Jill2Shay · Sep 2, 2013

Wow. That kinda sucks that they're giving no instruction.

Well, when speaking of water, 1mL = 1g

So, if you know how many calories per gram of the listed macronutrients, you could go from there.

1200mL = 1200g

25% dextrose (sugar = carb = 4 calories per gram) = 300g = 1200 calories

20% protein (4 calories per gram) - 240g = 960 calories

5% fat (9 calories per gram) = 60g = 540 calories

Add those up.

At least that's how I read the first question.

Please, someone else chime in if I'm incorrect.

monaa · Sep 2, 2013

I think Jill is right.

chare · Sep 2, 2013

Percent is used to describe the concentration. A 1% refers to a concentration of 1 gram dissolved into a volume of 100 mL.

For example; dextrose 7.5% I water (D7.5W) contains 7.5 grams dextrose per 100 mL water, or 75 grams per liter.

yayi4, ADN, BSN · Sep 2, 2013

thanks jill2shay , mona and chare i appreciate your help. :)

nurseprnRN, BSN, RN · Sep 2, 2013

hello, i am preping for my med math exam and i have no idea how to solve this . please teach me. thanks alot in advance. God bless.

You learned how to do these in your chemistry class, which is one reason you were required to take chemistry and pass it. If you haven't thrown your book away, you can pull it out right now.

This is another example of how nursing education is additive, that is, it expects you will retain prior learning to apply to new situations. This problem set is a perfect example of how this works.

1) the physician orders 1200ml tpn solution with 25% dextrose, 20% protein, 5% fat. how many calories is the client receiving in total?

Answer here is to be found in your nutrition book + your chemistry textbook, the part where you make solutions and figure out what is in them. How much dextrose is in a 25% solution, by definition? Remember you have 1200 cc, not one liter. How many calories per gram in dextrose? Ditto protein, lipids. Figure out calories for each, then add them up.

2) calculate the amount of dextrose and NaCl in the following IV soln: 2 litre of D5 1/3 NS
a) dextrose= _______ gram
b) sodium chloride =_______ gram

Chemistry text has this answer. By definition, what's a 5% solution of dextrose? How much dextrose per liter? (Note, you would double this for two liters)

By definition, what's normal saline? How much sodium chloride is that in a liter? What is one third of that? (Also note, double for two liters)

3) the physician order heparin drip 30,000units IV in 500 ML D5W to infuse at 3000u/h. the pharmarcy sends up a 10ML bottle of heparin sodium with concentration of 5000units/ml. the nurse would add ______ ml of heparin into the infusion bag. the nurse would set the infusion pump rate at _______ml\hr

If you have heparin at 5000 units per cc and you need to put 30,000 units in the bag, how many cc is that?

If you have put 30,000 units into 500cc, how many units are there in each cc?

If you want to give 3000 units in an hour, how many cc is that?

These are three separate questions, and you work them out individually. Show us what you get and we'll help you if you have a problem.

pleaseee help me figure out how to solve problems like this. thanks again. :)

nurseprnRN, BSN, RN · Sep 2, 2013

Wow. That kinda sucks that they're giving no instruction.

No, it kinda sucks that this student probably took chemistry and didn't expect to use it again after the final, and didn't remember to pull out the chemistry book to refresh her memory. This is precisely why nursing school instructors give these questions at the beginning of term, to see who remembers what.

Now, if this student didn't take chemistry before nursing school, then I have to assume that s/he would have had some sort of lecture on this concept before the quiz. OP, can you enlighten us?

monaa · Sep 3, 2013

I agree with Jill. They should give some instructions.

nurseprnRN, BSN, RN · Sep 4, 2013

I agree with Jill. They should give some instructions.

They DID give instructions. In Chemistry class.

What else would you have them do, tell the students how to solve the problem? They want to know if the students CAN solve the problem. What kind of instructions do you recommend, other than "Use your knowledge of solutions and calories per gram for each substance to calculate the following?" Is that enough of a HINT?

FDW630 · Sep 4, 2013

They DID give instructions. In Chemistry class.
What else would you have them do, tell the students how to solve the problem? They want to know if the students CAN solve the problem. What kind of instructions do you recommend, other than "Use your knowledge of solutions and calories per gram for each substance to calculate the following?" Is that enough of a HINT?

I'm not sure about OP, but I have never taken a chemistry class in my life. It was not required as a prerequisite, and I never even took it in HS. A math/chem tutor could be helpful here if your school has them. Ours has a nursing tutor specifically for us, and she does a LOT of med math. Some people just have a really hard time retaining math. Even super simple things. I know I do. If it weren't for my math whiz desk-mate I would be in hot water. If I don't use it all the time, I lose it quickly in that subject. Good luck, op!