What is back priming?

Nurses General Nursing

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Can someone explain to me what IV back priming is and when you would do it? I am a new grad RN working as a home care nurse and have been out of the clinical setting for a while. I don't recall ever back-priming anything when working with piggyback IV meds during clinical. Thank you in advance!

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When you have a secondary/piggyback, it may get air in the tubing when the medication has been instilled. You can back-prime the primary fluid up into the secondary tubing to displace the air in that tubing.

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Specializes in Med/Surg.

To back prime an IV line, you have a primary infusion already running, usually already connected to the patient. You then attach the secondary set, open the clamp and hold the set lower than the primary infusion until the primary infusion has traveled up the second set and into the chamber. You can then spike the secondary set.

The alternative would be spiking the secondary set and priming the second set with that medication, then connecting it to the primary infusion set. The reason I prefer to back prime (after checking compatibility, of course, is that you don't risk losing any of the secondary medication, and its a lot less time-consuming.

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Thank you for the responses!
So, basically, back priming is priming a secondary medication set with fluid from the primary infusion rather than fluid from the secondary medication itself.

And @LouisVRN, what do you mean by "You can then spike the secondary set"? Wouldn't it already be spiked with tubing prior to all of this? Sorry if this sounds stupid, but I am genuinely confused. :banghead:

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Specializes in oncology.

Correct = back priming is used to prime a secondary med w/fluids from the primary set.

Here's a scenario that might help describe it more: Let's say your primary line is connected to a 500ml bag of NS. You need to hang two different meds. The first is vancomycin. You attach that to the primary tubing and run it as a secondary.

Your vancomycin bag is now empty. You want to use the same tubing to hang your next med. Let's call it micafungin. Remove the vancomycin bag from the IV pole (all the tubing is still connected) and tip the bag upside down at a height lower than the 500 ml NS bag. Note the NS flushing through the vancomycin secondary tubing *and* into what was once an empty bag of vancomycin.

Your secondary tubing is now flushed with NS. You can disconnect the vancomycin bag and spike/run the micafungin bag.

Make sense? ?

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Specializes in oncology.

Also, you'll want to back prime 10-20 ml NS (just eyeball it) into that empty vancomycin bag before disconnecting to ensure that all the vanc is removed from the secondary tubing. This will avoid mixing potentially non-compatible IV meds in your tubing.

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Ahhh, nurse pants, you are a lifesaver! I learn best visually, so your scenario made it very clear to me :idea:. Big thank you to you and everyone else. I worry about keeping my skills current as I wait for that dream hospital job. Nine months and counting!

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Another question: You would change that secondary tubing according to agency policy, correct? There is a standard set up in every hospital as to how often primary and secondary lines are to be changed.

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Specializes in oncology.

Glad that helps. ? Yes - you'd change the tubing per policy. Our hospital is every 72 hours or whenever you start a new peripheral IV or change caps/reaccess a central line.

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Yes, it helps tremendously =)

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Baboosh123 said:

Thank you for the responses!
So, basically, back priming is priming a secondary medication set with fluid from the primary infusion rather than fluid from the secondary medication itself.

And @LouisVRN, what do you mean by "You can then spike the secondary set"? Wouldn't it already be spiked with tubing prior to all of this? Sorry if this sounds stupid, but I am genuinely confused :banghead:

There are a lot of great explanations answered here. However, If you are more of a visual person. Type in back priming in the YouTube.com search engine, and there are a few videos there.

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Specializes in LTC Rehab Med/Surg.

This question is kind of off-topic. We always use separate/different tubing for each piggyback we hang with a primary. I've always thought it would be so much easier to just use one tubing, back prime, to avoid incompatibilities and change per policy. I don't think my facility would go with the one tubing idea. Is there a policy where you work that prohibits using one tubing for all piggybacks? Do you use different tubing for each piggyback?

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