Drug calcs vs Pumps to do calcs

Nurses General Nursing


I read an interesting editorial in critical care nurse mag this month (missed the original article) but it was a question to the Ed about a nurse who felt that the author's (of the original article) decision to not instruct new critical care orientees how to actually do drug infusion calcs by formula, was a mistake. The author replied by saying she had polled everyone, etc, and based on her findings (more than just a poll) she decided against it. Her reasoning was that in the olden days she used to have to calc mean arterial pressure, ICP, etc... but now monitors did that for her and she was comfortable with that, it saved time etc... so why not use the technology to save time. The nurse who wrote to the Ed had questioned this though, b/c she had observed a problem one night where there were no more drug calc pumps left in stock, and dopamine had to be given via standard pump. She said on a unit of 6 nurses, only 2 knew how to calc the correct infusion rate.

So, it got me wondering. How many of you think that it is important to understand how to manually perform drug infusion calcs, and how many are fine to rely on the pump alone?

Me? Ya know I'm an old hag! I say know the formula, but I am thinking the author has a point, why not use the technology at hand to save time? But ya have to wonder, is this just a way to save $$ and time spent on the lengthy orientation to teach the drug calcs? And if so, why not develop a self-learning packet to teach it? I still think it's important, esp, like what happened to the one nurse, no drug-calc pumps were available. What if no one else learns this, only a few old dinosaurs like me are not working that night? I say it is a need to know, not a nice to know thing! How 'bout you guys??


455 Posts

I agree with you. I think we should know the formulas. If the technology is available, use it. If it is not available, we should know the formula to calculate it. Sometimes it takes me more time to find the calculator than it would to do the calculation using the formula. When I was in school we had a semester long course on pharmaceutical math. A helpful book is titled "Math For Meds" by Curren & Munday, published by W.I. Publications. If anyone is required to present an inservice in your unit, this might be a valuable topic to present.


349 Posts

You should absolutely know how to calculate it in your head, hands down. Relying on machines is irresponsible. Machines break. You have to have a way to double check them. Also, what about in cases of emergency, when machines either have no power to run them or are rationed (hurricane, earthquake...they happen here, too, folks!)? Any nurse worth his/her salt must know how to do this.


753 Posts

Specializes in Pediatric Rehabilitation.

This isn't taught in EVERY nursing school?????


6,011 Posts


OMG. Haven't they ever heard of microchip failure? Machine malfunction. Garbage in/garbage out? Shortage of supplies. Power outages.

How can you got out of school and into a unit situation WITHOUT knowing how?

Calculate, recheck, recheck, recheck, coworker confirmation, check w/ the pharmacy if necessary but DON'T rely ONLY on the machine.


213 Posts

I think it would be a great idea to have it posted so the info. is readily available i.e. procedure manual. As far as I know this info. is ALWAYS taught in nursing school. The problem is you don't use it you lose it.:cool:


216 Posts


I just started in the ER and did see an occasion where a drug had to be calculated by formula. I am also a year out of nursing school and we did not get the critical care calculations training in nursing school. Like the orders that are mcg/min and you have to know ml/hr.

I did get a packet during my first week and one of the first modules I had to complete was the drug calculation exercise. The book they gave us came from the ENA and it is very good.

As a new person to critical care enviroment I feel that you should be able to calculate the drugs the old way. Technology is wonderful and saves time and stress, but if the pump is not working correctly or in short supply you will have to know what to do as an alternative.

In my program learning drug calculations was all done on the student's own. They did not go over how to do it at all. They just gave us a book and assignments from that. I personally did not like learning math that way and I will keep practicing the critical care calculations until I can do them proficently.

As a new nurse, I feel we should know how to do both and I thank god for the experienced nurses who are willing to share their knowledge and expeirence with me!!!!



110 Posts

I believe in using the technology. However, I keep a small calculator in my pocket. During my first assessement and before I look at the charted values, I manually figure dosage calculations on each drip. I then compare my values to those before me and the values posted in the computerized charting system.

I do this at the beginning of the shift and if there is an error upon comparison, I problem solve it at that time. I do not recalculate as the shift continues, but use the automatic feature.

In this way, I do not forget the formulas and I have a double check on the values supplied by the computerized charting.

This saves some time and ,yet, keeps the formula in my memory in event of computer failure.

Blending the old way with the new technologies, I guess.


hoolahan, ASN, RN

1 Article; 1,721 Posts

Specializes in Home Health.

Wow, I am surprised by the number of you who learned this in nsg school. I didn't. I graduated in 1981 from a ADN program, we didn't even get critical care experience.

To tell you how antique I am, we never even used to calc dopa in mcg/kg/min, only mg/min when I first started critical care. Then a co-worker and I went to an inservice, and we became charged on how to do the mcg/kg/min dosing. We presented it to the staff and they wanted nothing to do with it. But, we persisted, and when we were on days, we started the flow sheet with the info in mcg/kg/min, so ohter shifts HAD to follow suit. Eventually, they all started doing it and saw the benefit of it.

I just finished a BSN program, and we did not have to review the drug calcs in that program either. It wasn't even in my first nursing math course the first time around. Good to know it isn't just us old fogies who didn't get it in nursing school, seems newer nurses have not gotten it either. When I became a preceptor, I was required to be sure my orientee had these cals down pat. I have taught this info more times than I can remember, and it really is easy with practice.

I agree that we should know how to do calculations by hand. I too, carry a small calculator. I write my calc. for drips out by hand, double check w/ coworker, then finally, will use the "technology" of my IV pump's auto calc. (it better match mine! ha ha). We learned basic calculations in nursing school. I don't work critical care, but do get cardiac drips on tele, so it's stuff I need to know. I always double check the calc on any drips when I come on shift, never simply relying on the previous shift's calc., or the "pump."

Specializes in Critical care.

I agree, all nurses should be able to calculate drip rates using formulas. Either be paper and pencil or calculator.. This is something I feel should be spot checked of the nurses critical care areas, give them a problem for something like Dopa or Levo, and see if they can do the math with paper and pencil and calculator. If not then maybe a short informal in-service is needed. This brings up another issue, I also feel that nurses working on TELE floors, should be able to read rhythm strips on the spot with a set of calipers, the nurses that work on the TELE floor get strips once a month to take home, which is good, but I think random spot checks where they interpret it there in front of someone are also beneficial....


624 Posts

Specializes in ICU/CCU (PCCN); Heme/Onc/BMT.

I agree with everyone's post . . . should be able to do calculations.

Ted Fiebke

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