Heparin flush and blood collection

[rnewmanjunkie]

I worked for a pediatric oncology hospital and I keep getting the same question. When a patient's central line, PICC, or SQP is flushed with heparin how long must the nurse wait until she can perform a venipuncture for coagulation studies without interference from the heparin. I had a pathologist tell me 90 minutes but I'm hoping to find something concrete in the literature. Any help is appreciated.

[RoyalPrince]

I usually wait 1 hour than waste 10ml red top and draw blue

[Biffbradford]

Well, they aren't 'flushing' the whole line are they? Just capping the end, eh? Then you're doing a peripheral blood draw? Just trying to clarify the situation.

[TinyHineyRN]

The practice in our PICU is to flush the line (PICC, port, art line, whatever) with 10cc NS, waste 10cc blood, then collect the coag. The only time I have had a problem with this is the other day when I was drawing a coag from an arterial sheath which is quite a bit larger than an art line. I just did a bigger waste the 2nd time and then my value was right on!

[MoopleRN]

Check what your facility's policy states and go by that. We don't do coags off a line unless there's an order. If a pt has coags and regular labs ordered, we don't draw because lab will have to peripherally stick for the coag so they can draw the regular labs as well, no point in accessing the line if they also need to get poked. On the rare occasion where we do draw a coag off a line, we waste an extra 10 mL before we draw.

Another thing to be aware of is when was the line last flushed with heparin? My facility says to heparin flush/check for blood return q shift (for a locked or running line). If I know I have to draw a coag, I'll wait towards the end of my night shift before I draw. That way, there's been a long time since it was last heparin flushed and I'm still following policy for blood return/heparin.

[nurseprnRN, BSN, RN]

also check to see if the line itself is one of those fancy ones impregnated with anticoagulant in the plastic.

[MunoRN, RN]

Depending on the source, IV heparin has a half life between 30 and 90 minutes. I don't know how it works in Peds, but in adults a heparin line flush isn't enough heparin to make a clinically significant difference in the ptt when a peripheral draw is done immediately following a heparin line flush. Our policy is to flush with twice the lumen volume, so in a PICC lumen for instance, you're only putting 130 units of heparin in the patient (now 13 since we've switched to 10unit/ml). Again, this is in adults, I'm assuming you use a different concentration or flushing protocol in Peds?