Injecting into a cannula; does syringe size matter?

[Thankgodforativan]

On my second rotation as a grad, first in ED, so I'm still picking up new things everyday. I had my charge chew me out earlier today for using a 3ml syringe to give 2mls through a 20 gauge in the hand, saying that it creates too much pressure on the vein.

I always knew this for PICCs - not to use less then a 10ml - but I didn't think this applied to peripheral cannulas, as veins are more 'flexible' (in most).

My first six month ED rotation, every nurse I worked with, even my seniors, didn't seem to be aware of this either. Has anyone else came across this in practice? I couldn't find any literature to back this up. Can anyone shed some light on what I (we) should be doing?

[RotorRunner]

I have no idea what your charge nurse was talking about. That is true for PICC lines, but it has been standard practice wherever I have worked to use 3ml syringes for certain IVP drugs.

You certainly didn't do anything to warrant a "chewing out". Maybe someone else has some input on this, because I am confused as well.

[Atl-Murse]

We do this all the time in pediatric PIV. Never heard of any issues

[AJJKRN]

I wonder if they're mixing their info with central lines myself...

[Double-Helix, BSN, RN]

A 20g IV can withstand up to 300psi (pounds per square inch) of pressure. Remember that the pressure you generate is a product of both the diameter of the syringe and the force applied to the plunger. Even if you push a 3mL flush as hard as you can, as quickly as you can, you're unlikely to exceed 300 psi. Using average or gentle force, you're probably only generating about 35-40psi. PICC lines (non power injectable), are far more sensitive, with a maximum pressure as low as 25psi.

So no, you aren't going to damage a 20g IV by using a 3mL syringe. Or a 22g, or a 24g.

[Flatline, BSN, RN]

A 20g IV can withstand up to 300psi (pounds per square inch) of pressure. Remember that the pressure you generate is a product of both the diameter of the syringe and the force applied to the plunger. Even if you push a 3mL flush as hard as you can, as quickly as you can, you're unlikely to exceed 300 psi. Using average or gentle force, you're probably only generating about 35-40psi. PICC lines (non power injectable), are far more sensitive, with a maximum pressure as low as 25psi.

So no, you aren't going to damage a 20g IV by using a 3mL syringe. Or a 22g, or a 24g.

This is not entirely true.

Each manufacturer of PIVs may or may not have engineered their catheters for different pressure ratings. Not all catheters are made of the same material nor are they all designed for pressure injecting.

Besides, the issue cited was damage to the blood vessel, not the catheter.

Source - Am medical device manufacturer in this space.

[Flatline, BSN, RN]

OP, you just have to inject with caution. This did not warrant a chewing out but you should be careful. The pressure of the injection is what is of concern, as long as you control the injection and do not forcefully inject it should be fine.

This is the main concern for central lines, if someone forcefully injects with a small bore catheter there is the possibility of damaging the catheter.

The short nature of the PIV and use of caution should mitigate the risk of this procedure.

[AgentBeast, BSN, RN]

The INS recommends using a syringe sized appropriately for the volume of medication being infused even with CVCs. The only difference with CVCs is that you verify patency first with a 10cc syringe and then use whatever size syringe best matches the volume of medication being given.

[MunoRN, RN]

10cc syringes aren't required for peripheral lines, central lines, or PICCs. So long as the line is patent, no size syringe will produce dangerous pressure levels, which is why the recommendation is to assess for patency with a 10ml syringe, then use whatever size syringe is most appropriate one patency has been established.

And as a side note, syringe size does not produce a particular amount of PSI, it only determines a ratio of pressure applied to the plunger and resulting PSI if injecting into a closed space (such as an occluded line), you can potentially produce much higher pressures with a 10ml syringe than a 1ml syringe, depending on how hard someone is pushing on the plunger which is not a standardized amount of pressure.

[Thankgodforativan]

Thanks for the responses guys and gals

[BedsideNurse]

The INS recommends using a syringe sized appropriately for the volume of medication being infused even with CVCs. The only difference with CVCs is that you verify patency first with a 10cc syringe and then use whatever size syringe best matches the volume of medication being given.

Hi AgentBeast. Was wondering what INS stands for? Also, was wondering if you knew of a link or website or article online where the INS recommends this? It's a small hassle, but injecting drawn up meds into a 10cc syringe takes time (and supplies) that I'd rather not use if it was unnecessary, especially in more emergent situations. Thanks. :)

[applewhitern, BSN, RN]

I have been an RN since 1989, and I use whatever size I want to for peripheral IV's. Never had a problem. Now I do use a 10cc on PICC's, as recommended.