Piggyback/Incompatibility-driving me nuts!

[Curious1alwys, BSN, RN]

Ok this issue is driving me nuts so I am looking to you all for help.

We are taught to backprime at my hospital. So, you have NS running primary and need to hang one ABX secondary. Couple hours later need to hang another ABX secondary. I get use same line, backflush. What is really annoying me though and I am hearing conflicting things about (and can't really understand the research that has been done) is:

If a medication is COMPATIBLE with the primary fluid running and does NOT require a dedicated line, it is OK to backflush even if the new ABX ready to hang is NOT compatible with the last ABX hung. ???????

I was trying to discuss this with a coworker, telling her I had seen research saying that regardless whether those two secondaries are compatible, you can backflush and hang with same tubing unless the med is not compatible with the primary fluid flush. She looked at me like I was totally crazy and stupid. I mean, if you are backflushing with NS all the way through the line and inverting the old secondary to squeeze any remaining old ABX back in the old bag before you disconnect and hang the new incompatible ABX, there really is no incompatible medication left, right? Especially when you consider dilution?

She pulled policy and it seems like the hospital wants new secondary tubing attached if new piggyback is NOT compatible. Then when you need to hand another med, you need to detach that tubing and attach another. When this practice ensues, don't you now have to change the IV tubing more frequently because you are opening the line?

Sorry, I'm a new grad and this is driving me crazy because I want to know best practice. I will follow my hospital policy but can you point me to any evidence based info on this? I only found one thing that said no one really knows with incompatible med backpriming but that backpriming compatible meds is preferred over disconnecting and connecting new secondary tubings.

HELP! Thanks!

[MunoRN, RN]

You don't really get rid of all of the previous drug (down the last molecule), but then again you don't need to. And if the rationale that absolutely no remnants of the previous drug could be left in the line made sense, then you couldn't just change the secondary tubing, you'd have to use a different primary and IV site as well.

All incompatibilities are safely dealt with by proper flushing since significant flushing of the drug is all that is required. Most drug incompatibilities are due to pH variations, which actually requires surprisingly little dilution by flush to negate. Other incompatibilities are also solved with dilution, think of multiple lumens infusing incompatible drugs simultaneously, it's all going to the same blood but it gets sufficiently diluted as the two drugs mix.

I've yet to a rationale argument as to why multiple secondary lines should be used, but it remains something that many nurses aren't going to budge on.

[Curious1alwys, BSN, RN]

Hey Thanks Muno. Good to know I am not totally crazy!!

Guess there is no evidence based practice research on this tho? Seems like they should have figured this out by now. I prefer this method because, frankly, as a new grad, I get really confused with a million lines hanging around!

[MunoRN, RN]

This has been figured out, although there are no RCTs on the subject, just like there are no RCTs are the safety of jumping out of an airplane with or without a parachute (although there is a review of the evidence).

The pharmacology community has no interest in actually studying this because there is no reason to believe it's an issue. We know the minimal concentrations that are required to produce an incompatibility based on chemistry, and we know that what remains in tubing after a flush/backflush is in exponentially lower concentrations than that.

There is however evidence that each additional tubing connection manipulation carries a risk and therefor should be avoided unless necessary, changing the secondary tubing isn't necessary which would seem to make it an action with only risk and no benefit.

[Curious1alwys, BSN, RN]

OK so my facility just doesn't acknowledge that evidence I guess since they still want a disconnect and new secondary tubing with any incompatible med administration (if the last piggyback is not compatible with the new piggyback despite primary fluid compatibility). I know I follow facility policy it is just that the nurses really made me feel like a bad, stupid nurse for thinking that backflushing between incompatible meds and leaving the sec tubing was horrible practice. I'm glad I got some clarification on this. Thanks Muno, ...again.

[MunoRN, RN]

The rationale behind what we do is based on various levels of evidence. There are ranking systems for research, expert opinion, etc. Unfortunately, "that's how I've always done it" often ranks higher than any other form of evidence. You have a huge advantage in that your critical thinking isn't clouded by the "how I've always done it" level of evidence. I've worked in various settings, and it's always been those with a high number of new grads that are the most up to date on current best practices, so don't assume that you know less just because you are a new grad.

Don't be afraid to ask for another nurses rationale and to present yours to them. If another nurse can't explain why their rationale is right or why yours is wrong, then it's not you who should feel like the "bad, stupid nurse".

[StillsmilingRN]

So are you saying you use the same secondary tubing for 2 different abx? Like u have NS as primary continuos; then abx1 u hang piggyback, 4 hours later abx2 is due u use the secondary tubing after back priming to flush the line and use it for abx2?

[MunoRN, RN]

So are you saying you use the same secondary tubing for 2 different abx? Like u have NS as primary continuos; then abx1 u hang piggyback, 4 hours later abx2 is due u use the secondary tubing after back priming to flush the line and use it for abx2?

Yes we use the same secondary tubing for all antibiotics. Keep in mind that even you change out the secondary tubing between antibiotics you're still using the same primary tubing.

[RNAimee]

On 4/9/2014 at 2:00 PM, MunoRN said:

You don't really get rid of all of the previous drug (down the last molecule), but then again you don't need to. And if the rationale that absolutely no remnants of the previous drug could be left in the line made sense, then you couldn't just change the secondary tubing, you'd have to use a different primary and IV site as well.

All incompatibilities are safely dealt with by proper flushing since significant flushing of the drug is all that is required. Most drug incompatibilities are due to pH variations, which actually requires surprisingly little dilution by flush to negate. Other incompatibilities are also solved with dilution, think of multiple lumens infusing incompatible drugs simultaneously, it's all going to the same blood but it gets sufficiently diluted as the two drugs mix.

I've yet to a rationale argument as to why multiple secondary lines should be used, but it remains something that many nurses aren't going to budge on.

I've been using the same secondary tubing for my patients, for my entire 16 years of being a nurse and I still come to work each day and find multiple secondary tubings hanging in my patients room.  With the current supply chain issues we are now short on secondary tubing that contains the plastic hooks, so we've resorted to using paper clips and rubber bands to lower our primary fluids...... and I still find multiple secondary tubings in rooms. errrr..... I wish the Infusion Nurses Society would explicitly say this practice is okay.