How to give IV antibiotics

Home Health Columnist / Guide · May 10, 2014

Moved to allnurses Nursing Student Assistance forum for best chance member advice.

Here.I.Stand, BSN, RN · May 10, 2014

You can find the rate at which to infuse the antibiotic either by looking up the drug in your drug reference, or sometimes if it comes w/ a pharmacy label it will specify how fast--"Infuse over 60 minutes," "Infuse over 30 minutes," etc. So if the antibiotic is mixed in a 100 ml bag of NS, and it is to be infused over 1 hour, you'd program 100 ml/hr as the rate and 100 ml as the volume to be infused (VTBI). If it's to be infused over half an hour the rate would be 200 ml/hr but the VTBI would still be 100 ml.

You enter the volume TO BE infused so the pump "knows" when to stop infusing. (If the pump keeps infusing after the bag is empty, you'll get air in the tubing between the bag and the pump.) Once you program the rate and VTBI into the pump, the pump calculates the volume INFUSED as the infusion goes in. So the second you hit "start," the volume infused will be 0. As the infusion runs, the VTBI will count down to 0 and the volume infused will count up to the VTBI amount that you initially programmed. Does that make sense? Take your 100 ml bag again. When you first start it, you have 100 ml VTBI and none *has* infused. When it's finished, that 100 ml *has* infused, and none is left to be infused.

The bag lower than the antibiotic is likely to keep the pt hydrated, or it could just be running at a slow rate to keep the IV open. The antibiotic is programmed as the "piggyback" option and the plain IV fluids is the "primary." Once the piggyback is all infused, the pump automatically changes back to infusing from the larger bag that's hanging lower.

I hope I'm making sense; it's easier to demonstrate it than to type it out. If I were you I'd ask your instructor to go over it again, and then next time you have clinical and see a nurse do it, ask her to explain it as she goes.

akulahawkRN, ADN, RN, EMT-P · May 10, 2014

I am an LPN student. During my clinicals at the hospital, the nurses use Sigma spectrum IV infusion. I am still learning on how to use IV pump.
For example, the order is Rocephin 2 gm
I noticed that they use 0.9 sodium chloride bag which is hung lower than the ATB
What is that for?
And also, when they set up the IV pump, it's asking for the rate, volume infused, etc.
This is what the nurse put:
Infuse: 200
120
Volume infused: 0
How do I know the rate and everything else? Please help me educate about how to give IV ATB. Thanks! Appreciate it

Why IV Piggybacks are set up like that has to do with water columns flowing into a common line. There's a bit of an explanation for why it works, but suffice it to say that when the primary bag is positioned at least 6 inches below the secondary bag, the secondary bag will flow and the primary bag won't until the fluid level in the secondary bag & tubing is at or below the fluid level in the primary bag. This is done so there's little to no chance of an air embolism. It also ensures that as much medication that's in the Secondary bag is given as possible.

The "Infuse" means "Volume to be infused" (how much fluid needs to go in)

The 120 number is the rate in milliliters per hour. So, in one hour, 120 milliliters of fluid will be infused.

"Volume Infused" is simply a running tally of how many milliliters has flowed through that pump from when the pump was started or the counter was reset. It's kind of like a trip odometer on your car that keeps track of how many miles you drove since you last reset it.

So, when the nurse programmed the pump for 200 mL at 120 mL/hour, logically you can expect that to run about 1.5 hours (100 minutes, actually).

Guests · May 11, 2014

the nurses use Sigma spectrum IV infusion. I am still learning on how to use IV pump.

I don't know this particular pump but they operate on similar principals.

For example, the order is Rocephin 2 gm
I noticed that they use 0.9 sodium chloride bag which is hung lower than the ATB
What is that for?
And also, when they set up the IV pump, it's asking for the rate, volume infused, etc.
This is what the nurse put:
Infuse: 200
120
Volume infused: 0

I'll start with, I don't know what "ATB" means but it probably doesn't really matter for our purposes.

So ceftriaxone generally comes in a phial with either 1g or 2g of medication in a powder which needs to be reconstituted... generally 1g in a 50mL bag or 2g in 100mL (20 mg/mL, right?)...

so how did they get it (the powder) in there (the bag)? In all likelihood, the nurse grabbed a 10mL saline flush, injected it into the ceftriaxone phial, and then inject the entire (concentrated) solution into the 50mL bag... and then did it again with a 2nd phial... or, had a 2g phial and did the same thing but into a 100mL... (big hospitals generally have different dose phials... small ones often do not)

So what did they have? A bag which started with 100mL of NS but now has somewhere between 110mL and 120mL of actual liquid in the bag which now includes the drug, the original NS, and the NS from the saline flush (or phial of sterile water, perhaps).

They could set the pump to run 1 gram of ceftriaxone over 30 minutes (which is typical... though it can go a whole lot faster if the situation calls for it)... but they don't have 1 gram, they've got 2 grams... in about 110 or 120 mL... even though they've got 2 grams, the nurse decided to get the infusion in over approximately 30 minutes so s/he set it to run at a nominal rate of 200 mL/hr...

The obvious question is then, "well, if there are 120mL in the bag and they're trying to run it over 30 mins, why not set it at 240mL/hr?" The answer is, "because, in practice, it doesn't matter if ceftriaxone runs in over 20 min, 30 min, or 40 min... and it's easier to hit 2-0-0 than 2-4-0... or, it's just pre-programmed that way because whoever programmed the pump didn't think about the reality that reconstituted drugs don't usually have nice, round volumes"

So what's the "120" about? That's the volume that needs to be infused... either because there really is 120 mL in there, or because the nurse is being expedient and thinking, "I just want the whole bag you stupid pump and I know there's about 110 mL so I'll just over-program the volume"... It could be 120, 200, 500... makes no difference... the pump will stop once the bag empties... you just don't want it to stop *before* the bag empties...

This is the reality of bedside nursing versus exam questions.

Please help me educate about how to give IV ATB. Thanks! Appreciate it

If you're wondering why a small bag of meds is placed higher than a large bag of IVF, just play with a manometer (clear tube with water) and you'll quickly realize that "water runs downhill," even in tubes. If you can lay your hands on two bags of fluid and two sets of tubing, put some food coloring in one bag that's higher than another (while both lines are open) and then lower it down... and then lift it higher... fundamental physics.

californiarebel · May 12, 2014

Thanks everyone! At least I have some idea on how to give IV antibiotics. My other question is: Does it matter what the order is? As long as it says "infuse over 30 mins" then the rate would be 200 ml/hr? At the hospital where we do our clinicals, they always have an order that says "infuse over 30 mins". I noticed the nurses always put 200 ml/hr for the rate. Thank u so much!

californiarebel · May 12, 2014

Thank you so much! My other question is: Does it matter what the order is? As long as it says "infuse over 30 mins" then the rate would be 200 ml/hr? At the hospital where we do our clinicals, they always have an order that says "infuse over 30 mins". I noticed the nurses always put 200 ml/hr for the rate. Thank u so much!

akulahawkRN, ADN, RN, EMT-P · May 12, 2014

Thank you so much! My other question is: Does it matter what the order is? As long as it says "infuse over 30 mins" then the rate would be 200 ml/hr? At the hospital where we do our clinicals, they always have an order that says "infuse over 30 mins". I noticed the nurses always put 200 ml/hr for the rate. Thank u so much!

This is basic math. If the amount to be infused is 100 mL and you run it at 200 mL/hr, in 30 minutes (0.5 hours) that 100 mL will have been infused.

If you have a bag that has 250mL and you're to give it over 30 minutes (0.5 hours) and you run it at 200 mL/hr, it's going to take longer than an hour to infuse that fluid. However, if you run it at 500 mL/hour, it will only take 30 minutes (0.5 hours).

Also, often it's safer to run something in slower than ordered (not always, but often enough...) so you could have 125 mL in the bag that says to infuse over 30 minutes. Instead of programming in 250 mL/hr for the rate that would result in a 30 minute infusion time, you could run it at 200 mL/hr and it would go in over 37 minutes instead - a little slower.

Guests · May 13, 2014

In the real world, the docs neither know nor care over how long antibiotics should or do infuse. They just want the bug juice in the patient... they leave the details to pharmacy and nursing.

The "infuse over 30 minutes" is tagged to the specific antibiotic, and many will say "infuse over 60 minutes" (for example, 1g Vancomycin or 500mg Flagyl)... some will even say, "infuse over 90 minutes" (e.g. 1500 mg Vanco)...

it doesn't really matter if it's 53 minutes or 68 minutes... though longer/slower is better... less irritation to the veins and less shock to the kidneys/liver (in some cases).

californiarebel · May 13, 2014

thank u all so much!