What is your policy/procedure for drawing blood for PTT from Central line....

off the top of my head:
IF heparin is infusing through the central line, the line that doesn't infuse heparin should be used but probably only after drawing off at least 20ccs of blood before the PTT is collected.
Even then the result may not be accurate.

The most accurate is a regular stick for PTT.

We used to do PT/PTT on central line patients with heparin used for line patency not for anti-coagulation therapy.
Even after drawing off 20 ccs of blood first, the PTT would often be way off. Then we would just do a peripheral stick if we had already tried the non-painful route first.
If you have a patient getting heparin anti-coagulation tx, I would definitely want an accurate PTT, if you are going to titrate the heparin to the results.

In hematology, we are seeing a lot less heparin drips with the increased use of LMWH.

Our hospital policy is that PT/PTTs are not to be drawn from any line. In some rare instances we have had docs request that it come from a line, but not often. If we can't get a venus stick, we will do an arterial rather than use a line draw.

We hold our drip for at least 5 minutes before drawing the labs. If at all possible we use a port other than the one infusing the heparin. If that isn't possible we use the heparin line, with a 10cc waste.

Very curious about this thread, as I work in NICU and we always draw coags via an arterial line if one is available. We draw back very small amounts of blood (0.5-3cc depending on the type of line) until the port is clear of any IV fluid, and then we take our sample. I don't remember ever comparing these samples to ones drawn peripherally at the same time.

How much heparin do you run in adult TKO lines? We use 2u/cc, which is a standard bag from pharmacy so I assume we're all in the same boat? We only run our TKO art lines at 0.3-1.0cc/hr. Do you suppose that makes a difference?

I wonder if we are allowed to do it because we only transfuse according to the fibrinogen level. Newborn coags are different than adult levels (I believe the PTT can be 3 times the adult value) but still, I'm concerned now!

Our heparinized art lines are mixed 1:1 for kids over 10 kg, and 2:1 for kids under; all our CVP lines are 1:1. We draw our usual volume of discard blood (about 2-3 ml) then our sample. Our lab will then Hepzyme the specimen to neutralize the heparin before running the test. We have special labels for these specimens and the lab will not run the Hepzyme unless the labels are on the tube and the requisition, and that it's been signed by the collector.

We run heparin at 50units/ml, always take bloods from a central line if there's one in situ (except cultures) - turn infusion off, discard 10ml then take specimen. A couple of times the result's come back high, and the lab have accused us of sending them the discard sample, but peripheral bloods have come back with a similar reading, which makes me think this technique is fine.

We draw them from the art line.

For PT/PTTs we can draw from an arterial line after a waste. Any other central line or peripheral iv it is not policy to draw from...must be a stick. ouch.
Per our policy we can draw from aline but can't do any other blood draws through central lines-triple lumens, cordis', piccs, etc-