pre-transfusion sample aliquot

[bloodbankgal]

Hi everyone!  

I want to know what other labs require when a tech aliquots a pre-transfusion sample tube. I am working on clarifying our lab's policy.

• Patient's full name and date of birth
• Typenex sticker
• initials of the tech preparing the aliquot
• date aliquot is prepared 

Is this acceptable? Is there a specific US standard out there that address this? 

Thanks for your help! 

[Dansket]

Why do you aliquot these blood samples? Do I assume correctly that you are separating serum/plasma from red cells?

I am adamantly opposed to routinely aliquotting pre-transfusion blood samples for several reasons. It is an unnecessary step that does not enhance the process. It iintroduces another potential point of failure.  It takes time.  Storage space requirements are effectively doubled. 

[bloodbankgal]

27 minutes ago, Dansket said:

Why do you aliquot these blood samples? Do I assume correctly that you are separating serum/plasma from red cells?

I am adamantly opposed to routinely aliquotting pre-transfusion blood samples for several reasons. It is an unnecessary step that does not enhance the process. It iintroduces another potential point of failure.  It takes time.  Storage space requirements are effectively doubled. 

Point noted... 

But won't there be potential of auto-adsorption of some sort or some effect on the sample if this step is not done? And when a type and antibody screen is performed, is it not common practice that tubes are spun down, separated and then tested? I guess I assumed it was common practice... when we send out Blood Bank samples to the reference lab, we are asked to separate the samples (plasma/serum from red cells) Please enlighten me... 

Thank you 

[Dansket]

To me, it is not a common practice, because I eliminated it wherever I encountered this practice.  Separating serum/plasma for a Reference lab is a separate issue because you are sending them a known problem.

Do you have an example of a problem that occurred in your facility that was directly linked to not separating serum/plasma from a whole blood sample immediately after centrifugation?  Did this problem occur in a known patient or a patient new to your facility?  Does this occur frequently, rarely or is this the only known example?  These are some of the questions I would ask before memorializing the process in a procedure manual.

Unless you have accumulated evidence to support the assertion that separating serum/plasma actually prevents problems frequently encountered in your facility, you have to look to other reasons to justify doing this. 

If this problem occurs in 1/10 patients, I would be doing it.  Otherwise, I view separation of serum/plasma from red cells to be a “solution looking for a problem”.

 

[Malcolm Needs ☆]

12 hours ago, Dansket said:

Separating serum/plasma for a Reference lab is a separate issue because you are sending them a known problem.

If you sent a separated sample to the Reference Laboratory where I used to work (it still seems so strange to say "I used to work"), it would have been rejected, unless the hospital was specifically requested to so do.  It is not that we did not separate the plasma from the red cells of most of our samples (we did in most cases), but we wanted to use a sample that, as often as possible, had not been manipulated by the Hospital Laboratory, and if there was to be a mistake made in the separation of the sample, we wanted to make it ourselves, rather than have it made for us!

[exlimey]

14 hours ago, Dansket said:

Otherwise, I view separation of serum/plasma from red cells to be a “solution looking for a problem”.

Couldn't agree more. Any time you start messing with samples you have the chance for mix-ups. Sounds like a bad idea.

[AMcCord]

 

1 hour ago, exlimey said:

Couldn't agree more. Any time you start messing with samples you have the chance for mix-ups. Sounds like a bad idea.

We've never separated samples and I've been doing this for 30+ years. We routinely add crossmatches to previously drawn specimens and do not experience problems using those samples. There are a very few specific times when separating a sample can be helpful, but I haven't had one of those events for years. Actually I can't remember the last time I did separate a sample. Our reference lab hasn't required separated plasma/red cells in a long time. It would be interesting to know why your reference lab requires it for all samples.

I would recommend against the practice of sample separation.

[AuntiS]

We used to separate samples here too (cells in the fridge, plasma in the freezer).  We didn't have any problems, but I felt like it was inevitable.  We don't do it anymore.  Saves everyone a step which makes everyone happy!  We also have fewer problems with cold precipitates and nuisance cold reacting antibodies after removing the plasma from the freezer for XM testing.

s

[SMILLER]

We have not bothered to separate specimens for some time.  It is, in fact, discouraged for the reasons stated above. I do not think this is common practice.

Scott

[jalomahe]

22 hours ago, AuntiS said:

We used to separate samples here too (cells in the fridge, plasma in the freezer).  We didn't have any problems, but I felt like it was inevitable.  We don't do it anymore.  Saves everyone a step which makes everyone happy!  We also have fewer problems with cold precipitates and nuisance cold reacting antibodies after removing the plasma from the freezer for XM testing.

s

 I am assuming you were freezing plasma for pre-admit surgery patients. How long were you allowed to use the frozen plasma for crossmatching? How long are you now allowed to use the non-frozen/refrigerated plasma for crossmatching? Are the time limits different depending on whether the patient has an antibody or not?  I'm curious because I'd like to move away from the frozen plasma hassle also but we allow patients to have their type/screen drawn up to 30 days pre-surgery.

[AuntiS]

We allow 28 days for pre-admit patients here in our hospital.  (Every other sample is good for 96 hours).  Same time frame now that samples are not separated as it was back when they were separated and the plasma frozen.  And, we have had no issues since making the switch.

s

[mcgouc]

We used to think cold antibodies & complement were important.  We did room temperature screens & crossmatches & we had to identify room temperature only reacting antibodies.   We could not use EDTA tubes in Blood Bank. So, we used clots, separated, & refrigerated immediately.  One day I asked myself why we were still separating the EDTA specimens increasing chances for mislabeling & mixing plasma tubes and couldn't think of a good reason so we changed our practice.  Thankfully, we did not separate specimens sent to the reference lab. 

[Mabel Adams]

We don't separate our EDTA samples unless we have to do an ID.  Then it is easier to access the cells with the 10 mic pipet for making a cell suspension for the auto control without getting the pipet all messy from passing through the plasma.  What do those of you who never separate do for that?  Use a plastic transfer pipet to reach down into the cell layer and pull some red cells out to another tube so you can access the packed cells with the 10 mic pipet?  We currently do tube types and manual gel screens.  I guess we could spin down the cell suspension we used for the blood type to get packed cells but it seems like it is hard to get the cells packed enough.  I'd love a better way.