Central line question?

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Specializes in NICU.

Ok so I want to know if anyone else has heard of this before.

I had a pt on a heparin drip who had a quad lumen central line. Well this pt had to have a PTT drawn every 6 hours per gusto protocol. I had the pt all weekend. And I would chose a port different from the one getting heparin of course... flush with NS, waste 10ml, and draw the PTT. Never thought twice about it...

Well when I came in to work today the charge nurse was in the room talk to the pt and family because they were apparently upset about something. Turns out it is against our policy to draw PTTs from central lines. The nurse after me had been sticking him to get his blood for a PTT. The pt was mad b/c they didn't want to be stuck since they had a line. saying "the other nurse drew it from my line, so why do i keep getting stuck!"

Well they ended up getting an order from the doc saying it was okay to draw from the central line.

Apparently plastic is porous, and the heparin used to flush central lines sticks in the pores.. and even after flushing and wasting, some heparin gets into your sample and messes up the accuracy of the labs.

Did anyone else know this? I didn't get in trouble, but now I know....

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Specializes in Hospice, Med/Surg, ICU, ER.

Yes, this IS true, but.......

The same heparin that sticks in the line, STICKS in the line - it does not infuse into the pt, nor does it flush, nor does it COME BACK when you draw blood.

Look to hospital policy for the "correct" answer. At my facility, we draw levels from lines all the time. However, the rule is that we d/c the heparin for 10 mins, flush the line, waste 5 mls of blood, THEN draw the sample. We then immediately resume the heparin at the current rate, waiting for the lab results before adjusting the rate.

The amount of heparin that MIGHT remain in the line is so small as to be negligible to the lab result.

Hope this helps.

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Specializes in ICU/PCU/Infusion.

If our facility used heparin to flush our central lines, I would not draw PTT's from them, ever. Not just not from the lumen where the pt. was receiving heparin (that's obvious, as you pointed out), but not from any of the lumens.

Other than that, labs from central lines such as IJ's, Subclavian's, etc, are okay to draw from per our P&P.

:)

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Specializes in Med-Surg.

It's our policy not to draw PT/PTT's from central lines.

Sometimes the patient refuses to be stuck and if enough is wasted, I've never noticed a problem.

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Specializes in ICU;CCU;Telemetry;L&D;Hospice;ER/Trauma;.

Clee1 is right on the money!

Many facilities are now going with just saline flushing due to the high incidence of heparin induced thrombocytopenia and other heparin reactions in patients...

A clearer policy in your hospital's blood drawing from lines might be helpful.....maybe you could suggest what Clee1 has stated??

It also depends on the location of the port you are drawing from....the most distal port is the one you should use, therefore, if the heparin is infusing upstream in the medial or proximal port, it is streaming past the distal port...right? so when you stop the gtt. / pull back the wasted sampling of blood/ usually 10-12cc...you are now only getting what is currently flowing in the blood stream...which is what you would want....blood doesn't flow backwards in the vein, obviously....so what is distal is your true sampling, after you have wasted; This is the accepted standard of practice set by the Infusion Nursing Society guidelines....and they are the gold standard....

crni

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Specializes in cardiac/critical care/ informatics.

I personally don't like to draw ptt/pt via line either esp. if heparin gtt is hanging. I have too many incorrect ptt. I agree that it doesn't make alot of sense. but it happens.

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Yes, this IS true, but.......

The same heparin that sticks in the line, STICKS in the line - it does not infuse into the pt, nor does it flush, nor does it COME BACK when you draw blood.

Look to hospital policy for the "correct" answer. At my facility, we draw levels from lines all the time. However, the rule is that we d/c the heparin for 10 mins, flush the line, waste 5 mls of blood, THEN draw the sample. We then immediately resume the heparin at the current rate, waiting for the lab results before adjusting the rate.

The amount of heparin that MIGHT remain in the line is so small as to be negligible to the lab result.

Hope this helps.

I agree this the way we do it too!

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