Do you still have to do dosages math by hand as an RN now?

Apples&Oranges · Feb 29, 2016

I thought this was ridiculous in school also - then I had to calculate my first Dilantin loading dose and drip...by hand. Thank goodness I learned dimensional analysis! I asked another new nurse to do the math independently to check me, and I immediately saw that her math was WRONG. Again, I am so glad that I had practiced to the point of disgust, and was sooo confident in my paper math skills, or I would have taken her at her word and 100x dosed the pt. I asked 2 other, more experienced nurses to do the math, and we came to a consensus. I then called pharmacy to QUINTUPLE check us all - we got it right. Drug calculations are no joke. You won't have to do it often, but when you do, you better do it right. I know it seems silly, but don't take it lightly. The one time you do it wrong, or don't take the time to ask for help, is the time you kill someone. We have new interns starting in July...they come up with some wild (and deadly) drug doses. I'll have my calculator handy.

BuckyBadgerRN, ASN, RN · Feb 29, 2016

I work in clinic, no pharmacy to mix meds for me! There is one procedure that we do that I have to get a height, weight, reconstitute the drug, draw up the appropriate amount based on h and w and then mix it with dextrose before infusing with an IV set that I had never seen before I took this position. So yes, you may have to use your nursing math skills once you've graduated!

vanilla bean · Feb 29, 2016

Every shift. On my unit (NICU), we do independent double checks on all meds administered. We also need to double check and verify IV fluid rates. All of our meds and fluids are weight-based, and while pharmacy mixes most of our meds for us, we still need to check their work. I once caught a pharmacy error - they sent the wrong volume of a medication and this was identified during the process of double-checking calculations and dosing.

Remember OP, as the person administering medications, *you* will be the last line of defense to catch/prevent med errors for your patients.

FurBabyMom, MSN, RN · Feb 29, 2016

I work in the OR and take care of patients of all ages (preemie to elderly). I definitely use calculations. We don't often have pharmacy's math for us to double check.

Also - like another poster said, having the knowledge of how to do these calculations may help you catch an error. If the concentration is generally 1:1 and they send something that is 2:1 from pharmacy - the amount to administer based on amount ordered may be different.

vintagemother, BSN, CNA, LVN, RN · Feb 29, 2016

There aren't really any "formulas". Its just algebra.

I use unit equations/ the ladder method/ dimensional analysis. Not the algebraic method.

wolf9653 · Feb 29, 2016

does somebody's life depend on it?

michlynn, BSN, RN · Feb 29, 2016

I almost never have to do any math, most electronic med administering programs will do it for you when you scan the med (always good to double check the dose of course!). I've never had to figure out a drip rate EVER, even if you don't have a pump for basic IV fluids they make tubing now with a gtt factor dial. The only basic formula I ever still use is the "what you need divided by what you have multiplied by the volume." Most IV pumps have meds pre-programmed with dosages so you type in the pt's wt and it calculates for you. Drugs like heparin come with a dosage chart based off of wt and lab work but it's just adding and subtracting, sometimes bolusing, nothing too crazy.

Clearly this is going to be different depending on where you work, some places still paper chart - including med administration, but most hospitals are converting to computer administration.

DoGoodThenGo · Feb 29, 2016

Yes, nurses still calculate dosages depending on the particulars of his/her particular environment. Maybe it's changed in hospital settings, but most of the time you will be asked to pass a medication administration test which includes calculations as a condition of employment.
I enjoyed learning it myself, because I learned the apothecary system (forgot what a drachm is, though!)as well as the metric system, both of which were unfamiliar to me at the time. Also speaking as a dinosaur, I don't think an a more efficient method being available or the ability to delegate something is cause to stop teaching/learning the basics.

I got you!

1 drachm = 3.55 mL

1 dram = 27.343 gr

1 grain = 64.8 mg

1 tsp = 60 gtts

1 mL = 15 gtts

31 g = 1 ounce

Oh the horrors! *LOL*

Taking the bus home one day last week a young girl was busy with flash cards. I looked over her should and what was she studying? Med dose clac! *LOL* Poor thing was memorizing conversions.

DoGoodThenGo · Feb 29, 2016

So I'm in my first semester and we're about to start on meds and knowing how to calculate. It seems pretty easy, we haven't started the subject but looking at the pp slides, it seems like it.
I'm pretty good in math and love math like crazy lol. Science I'm kind of bad in it but after a while I get the hang of it.
Anywho, so I was thinking today, "well as an RN at the job, would we still have to take out a piece of paper and calculate the dose on hand, how many tablet there are, expected dose, etc?"
How do you all do it on the job? Do your hospitals system automatically does it or what? I'm not worried about it. But I'm really curious, I'm always asking why to things that may not matter to others but matter to me [emoji4]

First count your blessings this is 2016 and not 1966, 1976, or even 1986. Back then you would most surely have been taught med dose calc same way other math subjects were taught; show all more, my way (the instructor) only or the answer will be marked incorrect.

Knew girls who were bright with math but their brains were wired differently it seems. They could get the correct answer but just not with the formulas assigned. Thus they either had no work to "show" or what they wrote didn't pass muster... No dimensional analysis then either. Oh and you had to know conversions (apothecary, metric, etc... ) by heart. Because the United States is one of the few major industrial countries that does not use the metric system being introduced to it as part of nursing threw many off.

Regardless of what systems and or methods are in place where you ultimately may end up working that does not absolve you from the legal and professional liability of correctly administering medications. Computer systems are only as good as the information someone has input. The old adage "garbage in equals garbage out" applies to calculators as well. If you don't know how to set up a problem properly and or what you are solving for then your answer will be likely incorrect via pen and paper or electronics.

As a professional nurse you are literally the last line of defense against a med error; your own or that of someone else. Back in the day it was taught "never to administer medications you have not personally prepared yourself". Well those days are largely gone as many meds arrive on floors/units prepared. That and or when cabinets are restocked things are placed in the wrong drawer. Adverse events do occur from such errors up to and including patient deaths. Fatal Drug Mix-Up Exposes Hospital Flaws

Nursing math is like the others; the more often you use it not only do you become better at it but develop a skill set that allows you to spot potential errors just by looking at an order. Just arriving at the correct number is great, but that is expected. Knowing how and why you arrive to that point is important. If physician enters a med order with patient weight given in kg (by error) and it comes up from the pharmacy dosed in lbs. or you calculate it that way hopefully a knowledge of "how" and "why" would tell you that the number is suspect.

mrsjonesRN · Feb 29, 2016

I have to do calculations every shift. We don't have a pharmacist at night. Plus I think it is important to know the dosage calculations, like other posters have said, just in case the pharmacist/ computer/ smart pump does not calculate a medication correctly.

Ultimately, the nurse is responsible for administering the drug so you have to know your stuff.

Apples&Oranges · Mar 5, 2016

And once again, glad I paid attention during that check, double check lecture... Today, I had a serious cardiac med drip, scanned the bag, hung the bag, all good, right? Cause it scanned green, so it must be right...right?

Double checked the dose in the computer to the writing on the bag (cause I'm paranoid) and realized the concentration on the bag from pharmacy was different than the concentration programmed into the pump - by a factor of 1.5. If I had not LOOKED at the numbers on the bag, thought, "Huh, one of these numbers seems a little off..." I would have overdosed my patient with a med that very likely would have caused her heart to brady down to an unsustainable rate. Maybe not in an hour, but over a couple hours? Yep.

I am the very first person to admit I make mistakes, but I am a shark when it comes to checking math. Pharmacy techs are people, too. They make mistakes just as often as we do. I count on them to catch my mistakes, and I do my best to catch theirs.

myhoagie02 · Mar 5, 2016

I thought it was silly to learn dosages in school until I got into real world nursing. I don't calculate much, but I occasionally do for cardiac drips and such. Also, don't always rely on your pharmacist to give you the correct calculations. A nurse in the ER I work in discovered a med error just before her and the doc were going to give the pt TPA. She asked me to double check her math and I got the same answer as her. She ended up having to write an incident report regarding the incorrect calculations done by the pharmacist!

Know your math!