probably a dumb question about PIVs and drawing blood...

[rach_nc_03]

hey- i'm a new grad, working in a picu...i had some issues for my first 2 months with an impatient and rather harsh preceptor who was more likely to say, 'why aren't you understanding this??' than to actually help me learn...so, for that reason, and others, i'm not where i (or my manager) want me to be; i'm still quite short on certain skills i haven't done, but i'm also sometimes working with preceptors who have that same incredulous attitude when i tell them i'm not familiar with a procedure. all that is background for my question...

i had to draw blood on a teenager who didn't have a working arterial line (where i usually draw blood). so i had to use an antecubital PIV that had MIVF running through it. i knew i had to disconnect the maintenance fluid, waste some blood, draw off my sample, give the waste back, and flush. the IV had a luer-lock positive pressure cap on it. my preceptor told me to use a tourniquet above the site. i don't understand the logic here...if i shut off my fluid, took off my waste, then got the sample, why did I need a tourniquet? i got a look that said i was just a complete moron for not knowing...but i'm not a moron, i've just never had to do it this way before. the only thing i can think of is that the cap was *not* a luer-lock, and I'm misremembering.

what am i missing here?

[P.TALLEY]

Interesting, something new to learn from everyday I suppose, since I work in an environment where patient's almost always have CVC or an Aline, I guess all the years I've worked in the ICU setting, I've never seen one ICU nurse draw blood from a PIV with a mintenance IV going, nor from a hep lock...Personally I would frown if I see someone do this, but mainly because probably of lack of knowledge from the standard of practice that's used in different places in the hospital. Now my question is, for the other ER nurses out there....Is this done in your ER? And for the floor nurses and ICU nurses....Are these done in your unit? What's the thinking behind doing this as oppose to having nurses stick patients then if the patient has a hep lock with a large gauge for drawing labs...Keeping in mind that there is backflow from that heplock....I'm sorry did I just learn to be a good phlebotomist out of a myth? ALL responses would be appreciated.

I AM A 9 YEAR LPN THAT IS ABOUT TO GRADUATE FROM A RN PROGRAM. I WORK ON A PED FLOOR HERE AND I CAN TELL YOU THAT MY BOSS WOULD RAIN HELLFIRE ONTO MY HEAD IF I TRIED TO DRAW A LAB FROM AN EXISTING PIV. IT WOULD NOT MATTER TO HER IF IT WAS BEING USED OR NOT. OUR POLICY IS THAT ONCE FLUIDS ARE ATTACHED TO THE CATHALON THAT IS IT FOR GETTING BLOOD OUT. WE DO TRY TO GET PRELIM LABS WHEN THE IV IS FIRST STARTED BUT AFTER THAT WE HAVE TO STICK OR LAB DOES. SOME OF THESE KIDS ARE HARD STICKS BUT GETTING BLOOD IS EASIER THAN STARTING AN IV SO IF YOU MESS UP YOUR IV THEN WHAT HAVE YOU GAINED EXCEPT CAUSING THE CHILD TO HAVE ANOTHER STICK OR MORE THAN ONE. I FOR ONE WOULDN'T DO IT AND WOULDN'T WANT IT DONE TO MY CHILD.

[Ladybug45RN]

Were I work we really are not suppose to draw from an existing PIV. However, there are times we do. If we have a child that is a hard stick or a child that is totally tramatized by getting stuck, we usually will try. I have heard that the PIV is more likely to go bad if used for labs. We have not had any issues with false lab values by using a PIV.

However, you did mention giving blood back (waste) which we are not allowed to do ay my hospital. Of course the waste from a PIV is practically nil anyway. But, our CIVs are 5cc's for each draw. That can certainly add up. On occassion we have had a doc write an order where we can give waste back if we use a closed system, but it is certainly nothing we do routinely.

[nminodob]

I guess peds is very different from adult med/surg. Where I work it is against our policy to draw from an existing PIV, unless we get the labs at the same time we start the IV (and then it isn't an existing PIV, it's a new one). Another thing the OP said that we never do - drawing off waste first and then re-infusing it after we draw the labs. Is that customary in peds? We would never do that...

[AdobeRN]

On the pedi floor I work it is not a policy but it is something we do not do. We try to get the labs during the initial IV start, if unable a lab tech will do it. Once an PIV is in & working we do everything to protect it. Sometimes there is too much of a risk of losing the IV with the blood draw.

Nobody likes to stick a kid multiple times. We try our best to make the experience not so traumatizing by using cold spray, LMX or a Synera patch prior to any lab draws or IV starts.

[HRM672]

This is an interesting thread.

We don't typically draw from PIV's unless we have just started it, because most of our patients are infants who are hard sticks and have small gauge IV's. We have occasionally drawn from a PIV if it is large and seems to have good blood return. On our floor we get labs at least once a day, and the risk of losing a 22 or 24g IV is too high.

It's also policy where I work not to return waste unless there is a specific order to do so, and there rarely is.

[ECUPirateRN]

I guess my thought is why stick a kid if you can get a non-hemolyzed sample from a PIV? On my peds floor we routinely draw daily labs from existing PIVs, even babies with 24s or kids with fluids running. If you flush well and get a good enough waste your results come back the same as a fresh stick. Of course, I have had hemolyzed samples from an IV but I have also had hemolyzed samples from a fresh stick. We don't have lab techs or phlebotomists to do our sticks. We the nurses do them all. If the kid has IVF fluids running, I just turn them off (at the tme of the draw, not 5 or 10 minutes), flush, waste, and draw. If I have dextrose in my fluids, my glucose level still comes back normal. If I have K+ in my fluids, my K+ doesn't necessarily come back high. In fact, many times I have been able to go into a baby's room at 3 in the morning, get my labs from the IV, and never wake up the baby or even the parent. I don't like sticking kids any more than I have to. Of course, if the lab comes back funky, I will stick them for it.

As far as returning the waste, the only place I have seen that is in NICU. We don't do that on our floor.

[SNJS]

Research supports that it's best practice not to draw blood from a PIV unless the IV has just been started and hasn't been flushed yet. Whether all hospital policies support this or whether nurses even follow those policies is another question. Of course it seems easier to prevent another stick, especially in children, but this is not the way it's supposed to be done. Basic nursing fundamentals say the specimen is invalid if taken from a used IV line even after waiting for a few minutes. Its unfortunate that your preceptor made you feel like a moron because she was in the wrong herself!

[umcRN, BSN, RN]

I know I am not a peds patient but I was recently in the hospital, in the ICU they put a big honkin 18g in my hand (I work peds cicu/nicu so 18 g seems HUGE to me!) to draw labs (I already had a 20 in my AC and they were trying to be nice by not having a piv in each arm) they said they would put those in their pts w/o a-lines for labs, however on the floor they were not allowed to even put in PIVS never mind draw labs off them...kind of strange in my opinion, especially for an adult hospital.

[Rookie12]

i work on a PICU and we will draw labs from a PIV if we can get them. We don't return waste on a PIV however, only on PICC lines or CVL's. Why is drawing labs off a PIV with MIVF running so different than drawing labs of a PICC with MIVF running?? I'm curious that this practice seems so different everywhere! What does the research say is wrong with blood from running PIV's?

[Double-Helix, BSN, RN]

In my PICU, we draw labs off of PIV's if we can get them. We get a fair number of DKA kids, and they always get two IV's. One is for their meds, fluids, and insulin drip. The other we save for blood draws. We are draw glucose levels and blood gases every hour on these kids and BMP, Mh Phos q 4. I can't imagine finger pricking or sticking a kid (or an adult) every hour for labs, so we use the PIV. We don't draw from the line for cultures (obviously) or for some labs that might give us false readings, depending on the IV fluid running through.

I do find, personally, that PIVs are more likely to become infiltrated or clotted if used for blood draws. I think it's due to manipulating the IV in the vein. I'll still try it, though, especially with a child who is a hard stick. Best case senario is I get the blood and keep the IV. Worst case, I have to start a new IV, which means another needle stick, but the child would have needed another stick for the labs anyway.

Central lines are larger and sit in a much bigger vein, so it's far less likely that drawing from a central line will cause a a problem with the line. The blood in the central line vein is also diluted more quickly than a peripheral (think larger vein, more blood, faster blood flow), so it's less likely that a central line draw will give you false results due to fluid running through the line.

We don't ever return waste, unless it's a kid that needs all the blood he can get and we have a specific doctor's order. And then I'll always get another RN to gently shake the blood in the waste syringe while I draw the labs. I've seen how quickly blood can clot in a syringe, and I can see how dangerous it would be to return blood that could be full of micro-clots, not to mention the greater risk of infection.

[brownbook]

As to your preceptor saying to use a tourniquet. Either you get a blood sample easily without a tourniquet, or you might not. If you didn't easily get a blood sample a tourniquet might help.

It is not essential to use a tourniquet, and if you have found good luck, success, without needing a tourniquet you do not have to use one.

Tell your preceptor you have drawn blood before from a PIV and have not needed a tourniquet. You might have a tourniquet tied loosely around the arm so if you didn't get blood it would be readily available to use.