Do you hold TPN for PICC blood draws?

[crawlyberry]

:specs:Hi...newbie here...When taking a blood sample from a PICC line which has TPN running in it, how long do you turn off the TPN before you can access the line? I know you are supposed to flush with NS, then discard 10cc's of blood, then access the blood sample needed, then flush again. But isnt there a rule about hold the TPN or certain fluids for a time? Thanks.

[NotReady4PrimeTime, RN]

I always hold TPN and any other infusion that might affect my electrolytes for several minutes when drawing from a PICC or other central venous line. What I do is turn off all the infusions that I can (obviously inotropes stay on!) then get everything ready for the draw. There's a lot of blood flow at the end of most central lines so that's usually long enough to move the infused fluids along. Then I clamp off the other lumens, flush the lumen I'm drawing from, aspirate my discard, get my sample and flush again. The results are pretty accurate that way, no glucoses of 62 mmol/L or K+ of 8... The RTs who run our IStats will have a funny look on their faces when they bring a contaminated result back... "Did you draw this right out of the bag?"

[crawlyberry]

Thanks so much....I appreciate that....But what is an inotrope? :icon_roll

[november17, ASN, RN]

crawlyberry said:

Thanks so much....I appreciate that....But what is an inotrope? :icon_roll

dopamine, dobutamine, etc

[NotReady4PrimeTime, RN]

Inotropes are drugs that affect the force of muscle contractions, especially cardiac muscle. Positive inotropes increase the force of contractions and improve contractility. The list includes drugs like epinephrine, norepinephrine, dopamine, dobutamine, calcium, digoxin, milrinone and prostaglandin. Does that help?

[iluvivt, BSN, RN]

Generally speaking you should not draw samples from a dedicated TPN lumen. If you have a single lumen PICC with TPN infusing you should perform a standard venipuncture. Of course,in desperation I have done this but it is not the norm b/c it does put the patient at an increased risk for infection,especially candida. Optimally you should have a dual or triple lumen PICC for TPN in the acute care setting as these patients often have frequent blood draws,abx and other meds. So lets say you have a DL Groshong PICC......shut off the TPN for one full minute...then draw your sample from the other lumen as follows......discard at least 2x the priming volume of the line...5-8 ml usually covers it in the adult population.....obtain your sample using at least a 10ml syringe..........transfer sample into tubes or bottles for culture using a transfer device if you have one. Agood practice is to flush the line before discard to assess patency and gets the catheter away from the vein wall if it is there. Always use syringes when drawing from a PICC as other devices are not recommended b/c pressure changes sometimes make it difficult to obtain specimens. Flush with at least 10 ml NS and optimally 20 ml using a pulsatile method. If you are using a positive pressure cap then flush and disconnect. If you are not using a PP cap you should use a positive end pressure flushing technique.

[RN1982]

If I have to draw from the port that is holding the TPN, I flush with 20cc of normal saline and waste 10cc of blood. It's always worked for me.

[mpccrn, BSN, RN]

shut it off for 2 minutes.....withdraw 10cc and disgard.....then draw your samples, hematology samples first leaving the chemistry tubes for last. if i have a pressor running in the PICC.....sorry, the patient gets stuck.

[blondy2061h, MSN, RN]

I rarely need to draw from the PICC lumen, but if I do I flush with 10ccs, waste 10ccs, then draw. I don't see what holding the TPN for any length of time would do as there would be nothing pushing it through and it would just sit there ayways.

[neatnurse30]

In our hospital we don't draw blood when TPN is running. Lab has to come and do standard venipuncture.

[november17, ASN, RN]

yea, checking your hospital's policy about this seems like a good idea. Usually they'll spell out the procedure for you.

[gradRN2007, BSN, RN]

Just a reminder, when drawing from a picc line or any line you still must follow the correct order of draw and hematiology is always after chemistry because if the EDTA K2 in the tube.

Old Med tech/newish RN