Blood clots & IV/central line tubing...When does this become a hazard!?

[RN A]

I've been a nurse for 2 years on a medical/surgical unit and have recently transferred to the ICU/CCU. I am currently working with a nurse preceptor for my orientation to the units. My preceptor is great and very knowledgable, but she seems to stress out over everything, both critical and minute. While I draw blood from PIVs/Central lines, she breathes down my neck saying that I need to hurry and that I'm going to slow/will cause a blood clot for the patient. Now, I understand the importance of drawing labs quickly and efficiently followed with a good flush (I've done this skill in my previous position), but my preceptor is the first nurse I've met who freaks out about leaving blood in the line for the few seconds that it takes to fill up your lab tubes with the transfer device. I've done some research online and find absolutely no info about clotting time within an IV line. Can leaving the blood in the IV line for the amount of time it takes to transfer the blood from the syringe to the lab tubes really develop a clot and cause damage to the patient? I feel like I'm going as quickly as I can and she expects me to be flushing my line while simultaneously filling my lab tubes...Is it necessary to be this rushed?

[MunoRN, RN]

I don't know of any research that determines the actual amount of time it takes for blood to clot in the lumen of a catheter, although we do know it does happen and we unknowingly flush clots out of a lumen from time to time without clinically obvious effects. The initial stage of clotting, platelet aggregation, doesn't present a huge risk since the body will break down a few aggregated platelets fairly quickly once it returns to systemic circulation, so all in all you're probably not looking at a huge risk by filling your tubes and then flushing. But what doesn't have apparent effects in one patient could cause serious complications in another so erring on the side of caution is a good idea.

Personally though I prefer to flush as soon as my draw is done, otherwise it's very possible I'll forget, and then you've got a clot you definitely do need to worry about. I transfer to the tubes after the flush is done. The nice thing about ICU patients is that they often have a transduced CVP hooked up to their central line which you can then easily add a VAMP to, this negates the need for transferring from a syringe to the tube. It is also possible to fill your tubes directly from the central line port, but you'll find a lot of disagreement about whether or not that's OK.

[nurseprnRN, BSN, RN]

Even a clot of moderate size that would form in or at the end of an intravascular catheter in that brief a time would be clinically unimportant. It would go right to God's own awesome little bloodstream filter, the pulmonary capillary bed. It would take a really, really big clot to do any harm there (surely this nurse isn't so ignorant of vascular anatomy that she thinks the patient will stroke, right?)* and it will not grow once it gets there; old-timers will remember when we got our heparin from beef lungs. :) You and I throw little clots all the time, and that's where they go.

Do what she wants while she's breathing down your neck, and then relax a bit. Just be sure your bloods aren't clotting or settling in the syringe before you get them into the tubes!

*(exceptions: known ASD or VSD with right-to-left shunt or single atrium/ventricle or overriding aorta, etc. with R to L shunting)

[Twinmom06, ASN, APN]

Is there a reason you don't screw a Vacutainer on to the end of the ports? I just took a class to learn to draw from port a caths and PICC lines and they had us use a Vacutainer - no syringe needed

[ChristineN, BSN, RN]

Is there a reason you don't screw a Vacutainer on to the end of the ports? I just took a class to learn to draw from port a caths and PICC lines and they had us use a Vacutainer - no syringe needed

Sounds awesome but not all facilities do it this way. I connect the vaccutainer if drawing off of a peripheral line but at my facility we use the 10 cc syringes directly connected to the central line for blood drzws

[psu_213, BSN, RN]

Is there a reason you don't screw a Vacutainer on to the end of the ports? I just took a class to learn to draw from port a caths and PICC lines and they had us use a Vacutainer - no syringe needed

A lot of times I can't get enough suction with just a vacutainer to draw blood from a central line. Now, I'm not an expert of this, and I don't know exactly how much suction can be safely applied to a central line (I'm guessing someone on here does), but for an established central line (i.e. one that was not just placed) I use the syringe method.

[Asystole RN]

Is there a reason you don't screw a Vacutainer on to the end of the ports? I just took a class to learn to draw from port a caths and PICC lines and they had us use a Vacutainer - no syringe needed

In the vascular access world this is considered a no-no. Directly connecting any kind of vaccutainer to a central line is considered sub optimal for several reasons.

[Asystole RN]

It is best practice to move as quickly as personal safety permits. Can it clot in the time it takes to fill your tubes? Sure, why not. Depends on your patient in all reality. Can it cause harm? Sure, especially if your patient already has compromised pulmonary function.

Is it likely to clot or is it likely to cause harm? Doubtful. Best practice though is to limit as many risks as possible, even the unlikely risks. The whole clotting debate is exactly why reinstilling the waste blood is considered bad practice in most circumstances outside of peds/NICU.

Personally, I draw, flush, and then fill my tubes. If the rationale is that the time it takes to fill your tubes is too short to clot inside the tube and thus pose little risk to the patient then the same rationale can be extended to sitting the filled syringe(s) down while you flush the catheter because you know, its not long enough to start forming a clot.

[Twinmom06, ASN, APN]

In the vascular access world this is considered a no-no. Directly connecting any kind of vaccutainer to a central line is considered sub optimal for several reasons.

PAC's and PICC's are not the same as a central line though correct (like an IJ)? We even have specially shaped ones for blood cultures. I have to preface that I work on an Oncology floor so many of our patients have really poor peripheral access

[Asystole RN]

PAC's and PICC's are not the same as a central line though correct (like an IJ)? We even have specially shaped ones for blood cultures. I have to preface that I work on an Oncology floor so many of our patients have really poor peripheral access

All PICCs are central lines, not all central lines are PICCs.

Anything that terminates in the central vasculature is considered a "central line" although they are generally not considered in place, or at least optimally placed, unless they are within the SVC and in the lower one third of the SVC at that.

Many places will directly connect vaccutainers to central lines but it is considered sub optimal practice.

[tokebi]

Many places will directly connect vaccutainers to central lines but it is considered sub optimal practice.

Do you know the reason?

We are taught to draw from PICCs using vacutainers. I once had a pt who was an RN working in another state request that I draw her labs using a syringe. I wondered if she was just being paranoid or if there really was a safety issue.

If vacutainer method really is sub-optimal, why is that? Is the reason serious enough to push for a policy change at my facility?

[Asystole RN]

Do you know the reason?

We are taught to draw from PICCs using vacutainers. I once had a pt who was an RN working in another state request that I draw her labs using a syringe. I wondered if she was just being paranoid or if there really was a safety issue.

If vacutainer method really is sub-optimal, why is that? Is the reason serious enough to push for a policy change at my facility?

Its a controversial topic but the theory is that it can cause catheter damage by collapsing the catheter, adherence to the vessel wall from the extreme negative pressure, and poses a risk of regurgitation.

Personally, I do not think it is a big deal especially for small lab vaccutainers. Definitely do not use large vaccutainers for procedures like therapeutic phlebotomies, I have personally seen regurg from those.

Edit: Even in the INS Recommended Policies & Procedures is includes the possible use of directly connecting vaccutainers, so saying it is controversial is an understatement. Not directly connecting vaccutainers is a newer movement in vascular access.