PICC line blood draw

[greyL]

What's the proper way to draw blood from a picc line? The other day I flushed with 10 cc's of NS, then wasted 10, then drew blood. But the lab called to say that the results looked wrong (extremely low hemoglobin level) and that the blood probably had saline in it. Another nurse told me that I'm supposed to waste more than I flush and that I did it wrong. Is that correct?

[Cinquefoil]

I've heard that studies have shown most nurses tend to exert a certain average amount of pressure when flushing that makes a 10cc syringe safest to use. I can try to chase down that research later if you want.

The vascular access team at my hospital says best practice is to draw and flush gently, even with 10cc's. I can ask them why...

[UnbrokenRN09, BSN]

I can't believe so many facilities still require a 10-20cc waste. My facility recently changed to a 5cc waste d/t the increasing problem of anemia. I've seen non-bleeding, non-surgical patients hgb level drop 2-3 points just from frequent blood draws. I always draw a 5cc waste and haven't had any problems with funky results. If I have an infusion going I stop it for about 2 minutes, flush, waste, sample, flush, change cap, restart infusion.

We only flush with saline, no heparin. We try to limit heparin as much as possible d/t HIT. It does seem like we use a lot of cath flo, but I tend to think it's more from improper maintenance than anything. We use the power picc, which utilizes a valve system instead of clamps. You use a push-pause method when flushing and drawing. Too much Constant negative or positive pressure eventually damages the valves, which can lead to the line clotting off.

However....at the facility where I work as an agency nurse, you're supposed to flush with 10cc of NS every 8 hrs or after each use followed by 10 units or 1 ml of a hep flush. That has always seemed wasteful and pointless to me to just use 1 cc out of a 10cc hep flush. They also call for a 10cc waste.

[Asystole RN]

brithoover said:

Can someone explain the reasoning of flushing with 10cc before your discard?

The most common rationales I hear are to adhere to always assessing patency before using the line and to ensure that the lumen is clear of any residual medication.

Is it entirely necessary? Probably not.

[Asystole RN]

MunoRN said:

Are we under the impression that a 10ml syringe limits the amount of pressure in the lumen?

PSI, or pound-force per square inch, is derived from dividing the amount of force by the surface area.

If a nurse exerts an average amount of force on a syringe then the PSI will increase or decrease based upon the surface area that the force is being applied to. A smaller bore syringe will have a smaller surface area in which in the force is being applied to and thus increase the PSI.

A 10mL bore syringe will not LIMIT the PSI but the bore of the syringe has a direct influence upon it.

Make sense?

[MunoRN, RN]

Asystole RN said:

PSI, or pound-force per square inch, is derived from dividing the amount of force by the surface area.

If a nurse exerts an average amount of force on a syringe then the PSI will increase or decrease based upon the surface area that the force is being applied to. A smaller bore syringe will have a smaller surface area in which in the force is being applied to and thus increase the PSI.

A 10mL bore syringe will not LIMIT the PSI but the bore of the syringe has a direct influence upon it.

Make sense?

I get the premise, the problem is that this doesn't limit the PSI a the plunger, it only changes the ratio of pounds of force at the handle to PCI at the plunger, it's still very possible for one Nurse create more PSI with a larger bore syringe than another would with a smaller bore syringe. The amount of force a Nurse exerts as anything but standardized.

You also have to remember that unless outflow is significantly reduced it's essentially impossible to produce these pressures inside the lumen, you'll only be able to produce peak pressures that are slightly above neutral pressures. Actually your best chance of producing a high peak pressure with a patent line is with high volume, such as with a 10cc syringe.

It's for this reason that the INS recommends checking patency with a 10cc syringe, not that a 10cc syringe is the only thing that can be used.

[mrb0619]

What are you all using to get the blood from the syringe into the tubes???

[Mommy&RN, BSN, RN]

Safety blood transfer device

[mrb0619]

Mommy&RN. Thanks for the quick reply.

[mmc51264, BSN, MSN, RN]

We are being told not to draw from PICCs If we have to, flush 10, waste 20, draw 10, flush 10, hep lock 5.

They are trying to avoid infections.

Also depends on whether they are single lumen or dbl lumen power ports (the power ports are better).

[greyL]

mrb0619 said:

What are you all using to get the blood from the syringe into the tubes???

At my facility we use blunt tip needles.

[RNnewbie2014]

Don't worry I had a similar issue with a chest port and I was taught to flush 10, waste in the flush also 10 mL.. Then get the amount of blood needed... Came back low levels of h and h.. We can access a heparin if needed.. But my patient was experiencing thrombocytopenia.. I just don't know how I feel about putting in heparin in someone having that.. Regardless if its a small amount or not.. So I let the day shift do it..

[RNnewbie2014]

And the only reason why using heparin was a question was because the port wasn't drawing back on the next few days that I had the patient.. Needless to say that was a ROUGH weekend for me ha