# Math for Nurses question

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hi! I just started my Math for Nurses class last week. We have 3 classes then 3 chances to take the test. I am doing ok memorizing the conversions but 2 types of questions are giving me a hard time. If anyone could help me that would be fantastic!

Question 1.How many drams would you give if the doc ordered gr xxiv and the bottle is marked gr xii/oz. Grains kill me, I have such a hard time with them. we have a few grain fraction problems that I can not get either.

Question #2. a patient is ordered 50mL D5W with 1 gm Kefzol over 30 min. How many drops per minute should the bottle be timed at if the drop factor is 20 gtt/mL?

I understand straight forward IV problems but when the time is under 1 hour I become confused. I think I have to double the amount of meds given, but would that increase the gtt/mL as well?

Thanks so much for any help. I hope this isn't too long.

Eileen

26,410 Posts

Hint: 1 grain can be either 60mg or 65 mg.

You will never see anything ordered in drams anymore, how old is your exam?

Dosages have been standardized.

Next problem: You are giving the drug in 50 ml over 30 minutes.

What would be your drip factor is you were giving it over one hour? How many drops per minute? Then just do the calculation to change the rate.

Please try again with these hints and see if you can figure it out first. :)

4,105 Posts

Specializes in Cardiac.

You will never see anything ordered in drams anymore, how old is your exam?

Dosages have been standardized.

I have to have a math test at the beginning of every semester, and if we don't pass then we cannot continue the semester. We also had to learn conversions for drams, grains, etc......It is on all tests.

And the other day a really old Dr. came in and ordered tylenol in grains. Those conversions really still do exist.

1,459 Posts

Specializes in Neuro, Critical Care.
Hint: 1 grain can be either 60mg or 65 mg.

You will never see anything ordered in drams anymore, how old is your exam?

Dosages have been standardized.

:)

My teacher for my pharm lab told us that she wouldn't be teaching us the apothecary system either bc it is not really used much anymore...she also said that most hosp/docs are trying not to use CC's anymore and we should use ml, is this true? I know that 1cc=1ml but have you heard this as well?

26,410 Posts

I have to have a math test at the beginning of every semester, and if we don't pass then we cannot continue the semester. We also had to learn conversions for drams, grains, etc......It is on all tests.

And the other day a really old Dr. came in and ordered tylenol in grains. Those conversions really still do exist.

I am surprised that your hospital pharmacy let him get away with it. There have been overdoses on meds because of this, I clearly remember one case in a peds ICU concerning tylenol.

I know they exit, but JCAHO has been issuing standards as to how medications need to be prescribed.

49 Posts

my mother was in the hospital recently because of a TIA and when they admitted her i noticed on the wall a list of abbreviations the nurses arent allowed to use anymore and cc was one of them. they have to use mL.

26,410 Posts

Exactly, and medications being ordered in grains isn't permitted either.

Must be mcg/mg/ or gram. There is a reason for this.

1,459 Posts

Specializes in Neuro, Critical Care.
Exactly, and medications being ordered in grains isn't permitted either.

Must be mcg/mg/ or gram. There is a reason for this.

good, that is what i thought...even though cc's arent being used anymore, how come all the syringes still have ccs on them or are we just practicing with old ones (the tempadots we used the other day were from 2001 lol)? do the syringes you guys use have cc's or ml on them?

1 Article; 1,146 Posts

Specializes in Nursing Education. Has 23 years experience.
hi! I just started my Math for Nurses class last week. We have 3 classes then 3 chances to take the test. I am doing ok memorizing the conversions but 2 types of questions are giving me a hard time. If anyone could help me that would be fantastic!

Question 1.How many drams would you give if the doc ordered gr xxiv and the bottle is marked gr xii/oz. Grains kill me, I have such a hard time with them. we have a few grain fraction problems that I can not get either.

Question #2. a patient is ordered 50mL D5W with 1 gm Kefzol over 30 min. How many drops per minute should the bottle be timed at if the drop factor is 20 gtt/mL?

I understand straight forward IV problems but when the time is under 1 hour I become confused. I think I have to double the amount of meds given, but would that increase the gtt/mL as well?

Thanks so much for any help. I hope this isn't too long.

Eileen

The standard IV formula would be helpful here:

total volume x gtt factor

total time of infusion

Therefore your drip calculation would be as follows:

50(ml) x 20(gtt factor)

30 minutes (total time)= 33.3 gtts per minute.

Just remember that if you bring your total time of infusion to minutes, you will be able to calculate in minutes.

However, it is important to note that most hospitals no longer manually set their drip chambers ... rather, they have IV pumps and most of the time, the calculation is based on gtts per hour. Hope this helps.

2,016 Posts

Specializes in Telemetry & Obs.

Drams, grains, etc may not be used in actual practice anymore, but they've been on every meds math test since I've been in nursing school. Gets my goat that we have to spend time learning such an antiquated system! :angryfire

1 Article; 1,146 Posts

Specializes in Nursing Education. Has 23 years experience.
My teacher for my pharm lab told us that she wouldn't be teaching us the apothecary system either bc it is not really used much anymore...she also said that most hosp/docs are trying not to use CC's anymore and we should use ml, is this true? I know that 1cc=1ml but have you heard this as well?

Actually, that is very true ... at my hospital, we have moved away from cc's and are now almost totally using ml's .... same with grains ... however, it is not unusual to have an older physician write an order for tylenol gr X for a patient. We have a stop check system in place and anytime the secretary processing the order, or the nurse noting the order, or the pharmacy filling the order notices this, they are to take it back to the nurse to get an order clarification for mg strength. This happens very infrequently and it is funny when the new grads see it, as they are suprised and want to know what it means. I guess I am geting old!

510 Posts

I am surprised that your hospital pharmacy let him get away with it.

Last place I worked all abbreviations and apothecary measurements were banned, and nurses and pharmacy were told to refuse orders from any physician that didn't follow the rules.

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