Question about 10cc syringes and picc/ports

[mappers]

Learned something this week. I didn't know you had to use a 10cc syringe to administer meds through a picc or port. I know you have to use them to flush a picc or port.

This is what I heard in school....Always use a 10cc syringe to flush a picc or port because of the pressure. OK, so I took this to mean that a 10cc syringe delivers more pressure, and you need the pressure to really flush and clean the line. I know it takes more physical strenth to push larger syringes. Obviously I was wrong, but my logical brain isn't making sense of this. Pts with peripheral lines will complain that a 10cc flush hurts, but just pushing a 3cc of meds doesn't. There just doesn't seem to be as much pressure behind a 3cc push. I if I push 10ccs into the sink, it sure shoots out harder than if I push a 3 cc into the sink.

So, more than one nurse told me that a 3 cc has more pressure and you risk damaging that actual end of the line. I want to believe them, but like a said, my brain just can't wrap around this. So can anyone tell my why in a way that makes sense?

And how do you drop up really small doses then? Or oddball doses like Solumedrol where you're drawing up 1.28cc or .96cc? I had a lady who was getting .125cc of dilaudid.

[IVRUS, BSN, RN]

SocalVARN,

It is the syringe barrel that determines the PSI's that will be exerted on the IV catheter. A 10cc syrninge barrel will generate less PSI's on the IV catheter than a smaller 5 or 3 cc syringe. BD syringes which are prefilled all have the 10cc barrel PSI's so one can safely use a 3 in a 3, or 5 cc in a 5ml syringe without fearing catheter damage using normal hand decompression.

The ease at which one depresses the plunger on a 3cc or 5 cc syringe is what generates the inner luminal pressures. It is harder to push a 10 cc syringe barrel against resistance, though it can be done, unfortunetly and with unwanted consequences.

[jadelpn, LPN, EMT-B]

Edited out due to incorrect content.

See 2 replies below this one--excellent explaining--

If there ever comes a day I become an RN, I will remember these answers.

Thank you

[sapphire18]

10cc syringes must be used on PICCs, central lines, or ports due to the pressure exerted on the lumen, not because of the extra volume of flush. It doesn't take 10cc to flush through the line.

[jadelpn, LPN, EMT-B]

My error. I was told it was a volume situation as opposed to a pressure situation, as the lumen is longer.

Interesting. Learned something new. Thank you!

[IVRUS, BSN, RN]

Jade,

The Internal diameter (ID)of most PICC's is usually less than 1.5 cc, and many are around .9 to 1 cc to prime.

INS standards say to use (at least) twice the ID volume to flush. So, P&P vary institution to institution.

Now ports due hold larger priming volumes, but again, I haven't seen them hold amounts in excess of 2 mls per lumen in most cases.

[MunoRN, RN]

Can someone please explain to me if a 10ml,a 3ml and a 1ml syringe have the same sized hub or exit hole, then how could the smaller piston in the 1ml or 3ml syringe forcing less liquid through the same sized hole produce more resistance or presure? Did someone invent new laws for pressure and resistance?

They can all produce the same PSI. The only difference is the amount of force needed to be applied to the plunger to produce the same PSI at the plunger. One pound of force applied to plunger with a smaller surface area will produce more PSI than a larger one because more force is being applied when you figure it as 'per square inch'.

That doesn't mean that a 10ml syringe produces less pressure, if one Nurse applies lighter force on a smaller plunger diameter syringe (ie 3ml) than another applies to a 10ml syringe, the 10ml syringe could easily produce more pressure. It's basically just using mechanical advantage; you're moving less volume while pushing the plunger a longer distance.

The differences in potential PSI at the plunger doesn't actually mean more pressure is being created in the lumen however. In order for pressure to increase, there must be enough resistance to pressure escaping to allow pressure to build. If the line is widely patent, there will be minimal pressure in the lumen regardless of what size syringe you use or how hard you push. Imagine blowing into a balloon, it's fairly easy to create increasing pressure within the balloon even if it has a small hole, so long as you are introducing pressure faster than it is escaping. Now imagine cut off the end of the balloon opposite the end your blowing into. No matter how hard you blow, the pressure won't build.

[IVRUS, BSN, RN]

Muno is right in that it is the force applied meeting pressure from a narrowing, or occlusion in the catheter that becomes the issue.

No occlusion = no resistance, and that is why you can ascertain placement with a 10 cc syringe, and then if there is no resistance, give my IV lanoxin with a 3 cc syringe.

But if resistance is felt, and one is using a 3 cc syringe to ascertain patency, a 3 cc generates greater intraluminal pressure which can send that occlusion into circulation.

[ivnrse]

The BD posi flush pre filled syringes come in 10cc volume saline and 5cc and 3cc volume heparin flushes. The 3cc and 5cc volume syringes are barrelled / gaged to emit a 19.75 psi.

[DeanC]

The ISMP Report for Safe Medication Administration (http://www.ismp.org/Tools/guidelines/ivsummitpush/ivpushmedguidelines.pdf) latest, EVIDENCE BASED guidelines state:

5.4 Assess central line patency using at a minimum, a 10 mL diameter-sized syringe filled with preservativefree

0.9% sodium chloride. Once patency has been confirmed, IV push administration of the medication

can be given in a syringe appropriately sized to measure and administer the required dose.

Discussion: Care should be taken when assessing for central line patency to avoid possible catheter rupture.

Manufacturers recommend using at a minimum, a 10 mL diameter-sized syringe for assessing patency because a

syringe of this size generates lower injection pressure. After patency has been established, however, medications

can be administered in a syringe appropriately sized for the dose of the IV push medication required.18 Many

facilities have created policies stipulating that a 10 mL syringe be used for all procedures involving a central line,

when in fact, it is not necessary to introduce risk through a syringe-to-syringe transfer in order to administer

medications