Returning wasted blood to a line?

RoxanRN · Nov 16, 2006

The only time I return 'waste' is when it's been collected in a 'vamp.' Otherwise, there is too much of a risk of contamination of the blood/syringe of otherwise wasted blood.

augigi, CNS · Nov 16, 2006

The amount of wastage required depends on what lab you are drawing. Eg. for a blood gas, 5ml may be enough, but if you're taking a PTT for a pt on heparin infusion, you might need to waste more.

I would never return the wastage.

Dinith88 · Nov 17, 2006

When you draw blood from a central line, or an a-line, or a peripheral IV, you first draw out a few mLs of "waste" blood, then you draw your labs, then flush.
What do you all think about the idea of drawing your waste blood, drawing your labs, RETURNING THE WASTE BLOOD TO THE LINE, then flushing?
I had read about this on a previous post a while ago. I havn't done it.
And a seperate question, how many mLs is sufficeint waste?

I'm unaware of any 'new' or 'current' literature that suggests returning 'waste' blood may be safe...

But, the reason we DONT return waste blood is simple...anytime you remove blood from your vasculature and expose it to air, or syringe-walls, or whatever, you'll initiate the clotting cascade (can happen in seconds). If you return the blood it could potentially result in emboli...that's not to say it WILL happen...just that it could.

The blood that we return to the patients from auto-tranfusers (ie post cabg, etc.) i believe is less likely to clot because of the lining of the auto-tranbsfusion systems(???)...and some surgeoens will even have us instill heparin into the auto-tranfuser blood (which is a bit of a controversy)..

REGARDLESS, the thing to remember is that the blood returned in this way will be filtered...to prevent introduction of clot back to the patient...whereas 'waste' blood from central lines is not...

aquaphoneRN · Nov 18, 2006

The only time I return 'waste' is when it's been collected in a 'vamp.' Otherwise, there is too much of a risk of contamination of the blood/syringe of otherwise wasted blood.

Thanks for taking the time to reply.

What's a "vamp"?

aquaphoneRN · Nov 18, 2006

I'm unaware of any 'new' or 'current' literature that suggests returning 'waste' blood may be safe...
But, the reason we DONT return waste blood is simple...anytime you remove blood from your vasculature and expose it to air, or syringe-walls, or whatever, you'll initiate the clotting cascade (can happen in seconds). If you return the blood it could potentially result in emboli...that's not to say it WILL happen...just that it could.
The blood that we return to the patients from auto-tranfusers (ie post cabg, etc.) i believe is less likely to clot because of the lining of the auto-tranbsfusion systems(???)...and some surgeoens will even have us instill heparin into the auto-tranfuser blood (which is a bit of a controversy)..
REGARDLESS, the thing to remember is that the blood returned in this way will be filtered...to prevent introduction of clot back to the patient...whereas 'waste' blood from central lines is not...

Yeah, there's no literature on this.

My fear is that the blood will clot, and it doesn't seem worth the risk to return 5 - 10 mL of blood.

Interesting points you bring up about autotransfusers.

Anyone know how PRBC blood from the blood bank is processed to prevent clotting?

Tweety, BSN, RN · Nov 18, 2006

Never heard of that. We've recently decreased waste that we do from blood draws from CVLs from 10 cc to 5 cc. But still waste 10 cc for PICC's.

Hoozdo, ADN · Nov 19, 2006

Thanks for taking the time to reply.
What's a "vamp"?

The part of an A-line that you pull up on to pull blood from the artery. The blood that goes in the vamp is the waste blood. You push the vamp back down to infuse it back into the patient.

nursprl · Nov 19, 2006

in some facilities its common in peds/nicu since those patients are small and have smaller blood volume. just be careful to use clean technique like capping the waste syringe before drawing your sample. you should be able to draw your waste and sample and return the waste under 90 seconds or less. any longer than that then the the waste has to be thrown away. the heparin from an a-line waste is just enough to keep it from clotting until its returned to the patient within that 90 sec time frame. because of habit i do it on bigger kids as well.

augigi, CNS · Nov 19, 2006

PRBC from the blood bank often have citrate added to prevent clotting.

Dinith88 · Nov 19, 2006

in some facilities its common in peds/nicu since those patients are small and have smaller blood volume. just be careful to use clean technique like capping the waste syringe before drawing your sample. you should be able to draw your waste and sample and return the waste under 90 seconds or less. any longer than that then the the waste has to be thrown away. the heparin from an a-line waste is just enough to keep it from clotting until its returned to the patient within that 90 sec time frame. because of habit i do it on bigger kids as well.

Thats a good point...

even on adults, a-line 'waste' is given back to patients. The difference between a-line 'waste' and cvc/picc-line waste is that a-line waste never hits air (it's contained in the a-line system...)...and maybe 'waste' is a bad term for a-line blood...

I'm unsure about pediatrics/nicu, but do you mean you'll draw a syringe-ful of blood, remove it, use another syringe to draw the specimen, then re-instill the blood from the first syringe? And do you know if the '90 second rule' is just facility policy, or common/best practice? Thats really puzzling to me. Thanx for the ino.

At least in adults, it's called 'waste' for a reason.

augigi, CNS · Nov 20, 2006

Thats a good point...
even on adults, a-line 'waste' is given back to patients. The difference between a-line 'waste' and cvc/picc-line waste is that a-line waste never hits air (it's contained in the a-line system...)...and maybe 'waste' is a bad term for a-line blood...

Perhaps this is true for you, but not for any (Australian) unit. We use a 5ml syringe to draw waste off, discard, use an ABG syringe for the sample, then flush.