How long does it take you to calculate the doctor's med/IV order?

nminodob · Jan 10, 2011

Nowadays between the pharmacy and the "smart" IV pumps, most of the math is already done for you - I'm not talking peds because I don't work in that area, just med surg. Of course it is critical that you be able to verify the math as well - otherwise you will have missed out on the RN check that may be the last opportunity a med error is caught. And sometimes even the pharmacy makes errors!

The most difficult math I have come across was a pt on an argatroban drip - the rate was calculated by mcg/kg/min, and the concentration in the bag was 1 mcg per ml I believe, and the rate was titrated according to the latest PTT. Of course, the pump was in ml/hour, not mcg/min. We all had fun checking the math on that one!

What I have learned so far is that the most importnat thing is to get someone to double and maybe triple check anything critical, never let that uneasy feeling go unheeded!

regularRN · Jan 10, 2011

As mentioned above, the pharmacy usually sets the rate that are then programmed into the pump by the nurses. However, nurses are responsible for ensuring that IVs run at the correct rate so it is prudent to double check with another nurse - I have never met another nurse not willing to check IV calculations with me and vice versa. After a while you will become familiar with regular IV med rates.

IV heparin comes to mind as a drip that nurses have to calibrate on the med/surg floor... the hospital will have a policy and nurses follow that procedure, a second witness is usually required, but even triple checking can do no harm.

There is nothing wrong in asking other nurses' opinions, advice etc. - even seasoned nurses have not seen everything. Patient safety is paramount.

carolmaccas66, BSN, RN · Jan 10, 2011

All the pumps in Aussieland that I have used calculate the drip rate for you. We have our little cards we carry as well that we check that has all the drip rates calculated already for common IVs, ie: NS (normal saline) over 8 hours.

But you also have to be careful with pumps as there are different modes and screens you go into, ie: you may want something in drops per minute, or mls per hour, you need to check what mode ur in. The pumps we use calculate mls per hour.

BUT even though they do this I always quickly calculate it and get someone else to check, usually so it doesn't take too long, maybe a few minutes.

And if ur new, you should ALWAYS be asking someone to do and check calculations with you, it is not as easy as it sounds, but you will eventually get the hang of it, and start to do some in your head.

I don't do peads but their drips are always calculated in mg/kg/hour so that is different, but not too difficult.

My biggest advice to new people as a RN is don't EVER rush calculations. And if ur still not sure don't give the medication. Always get someone senior to check your calculations for you. And start doing lots of revision and calculations at home, just simple ones to get you into the swing of things.

Believe me I was an absolute dunce at maths and if I can get the hang of it, so can you!

JulieCVICURN, BSN, RN · Jan 10, 2011

About as long as it takes me to dial the pharmacy and ask them, and that's only if none of the methods described by the above posters is available. I don't think I've had to calculate anything outside of heparin dosing since graduating.

ETA: You should still do it if you're new. Ultimately, the responsibility falls on you if something goes wrong. I have seen more than once a smartpump screw up and overdose a patient.

Flo., BSN, RN · Jan 10, 2011

After a while you will know the normal rates of the IVs that the floor uses.

Do not worry about fast, only worry about right.

Heparin is the only drug that is calculated by an RN on my floor. Even then I call pharm and ask them do the calc. Then I double check them and have another RN triple check it.

We have some great pharmacist and they would rather do a quick calculation than have us mess up.

RescueNinja2013 · Jan 10, 2011

wow! i didn't expect four replies so fast lol. thank you! do you (in general) ever feel incompetent, or think that your fellow coworkers think your incompetent for asking? how do you reply when you (if when) you get smart butt remarks, like, "you're a nurse, you should know" type of attitude? even though i know pt safety is far more important, i'm just curious. do you ever forget any calculation formulas? do you have the formulas with you on a note card? -for all medication, not just intravenous. and with a lot of the calculations being done by pharmacy or smart machines, do you just brush up on your math skills when board rectification comes around? i am so glad i found this site a while back -keep your replies coming! thank you!

JulieCVICURN, BSN, RN · Jan 10, 2011

1) I don't remember any calculation formulas. At all. If I ever do have to use them, we have references available on the unit. And still, my own math is so iffy that I don't do anything without double checking it with pharmacy. No offense to nurses, but most of the ones I work with aren't much better at math than I am. We all trust pharmacy more than each other in my unit.

2) It depends on your environment. Nobody in my unit ever made me feel stupid for asking anything, no matter if they thought it was stupid or not. I hope that you are as lucky.

3) What recert? If you are in the US, you don't ever get tested again to keep your license. You just pay to renew every time the renewal rolls around. The only thing I've ever had to recert in was ACLS, PALS, and BLS, and I don't recall any math being part of it.

RescueNinja2013 · Jan 10, 2011

Thank you for your input Julie! Thank you all! I always thought there was another retake of the NCLEX! Silly me lol. LPNs don't need to retake either, I'm assuming. I am just trying to build my confidence here, even though I haven't even started the lpn program yet, I'm in for a long road.

JacknSweetpea · Jan 10, 2011

However long it takes me to get ahold of my lifeline...

NeoNurseTX, RN · Jan 10, 2011

We double check everything we draw up anyway.. and I've asked people to double check and triple check things with me because I'm so afraid of swapping numbers around.

carolmaccas66, BSN, RN · Jan 10, 2011

In Aust we double check everything - I even check NS for a flush which many nurses I've noticed do not.

The other poster was right - don't worry re speed, it is better to go slow than make a huge error where you've just injected something then thought uh oh.

If someone puts you down for checking - and they should not but it happens - go check with someone else more senior. Don't ever give meds if ur unsure, I don't. And you have resources on the ward usually, if not take a little calculation book with you. Your NM or CN should know re calc's but not always.

I've never rung pharmacy for help myself but you could use that as an option. It's better to be safe than sorry as they say.