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Hemolysed samples for pretransfusion testing?


Byfaith

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We have always used a cutoff of 50mg/dl hemoglobin concentration (Visual color chart).  We use EDTA tubes and Provue analyser.  Are we overdoing it?  Sounds like many places take everything but gross hemolysis, and even those on an urgent case.

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We are still doing it the old fashioned way -- manual gel -- but if the plasma is so dark that you cannot tell the difference between it and significant hemolysis (thinking possible transfusion reaction comparison), I would think you would want to have it redrawn.  We let sight hemolysis pass with a comment added to the specimen when it's checked in.  Not sure but I would think that would be around 50 mg/dl or less.

For an automated platform, can you not consult specimen requirements from the manual?

Scott

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It seems to me that the only time hemolysis comes with an acceptance/rejection gradient is with washing RBCs (at the institutions I've seen). At least for that there is a color hue chart to match.

If the gel can't discriminate between the layers, it tends to just call it DP and it gets sent for tube testing. I've never seen a sample rejected based on hemolysis...

Is there literature to dictate a cutoff?

 

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5 minutes ago, Ward_X said:

It seems to me that the only time hemolysis comes with an acceptance/rejection gradient is with washing RBCs (at the institutions I've seen). At least for that there is a color hue chart to match.

If the gel can't discriminate between the layers, it tends to just call it DP and it gets sent for tube testing. I've never seen a sample rejected based on hemolysis...

Is there literature to dictate a cutoff?

 

There is older literature referring to the concept of hemolysis as a positive reaction interpretation.  I believe this is relavant only to tube testing.  There is also the fact that using EDTA samples complement does not come into play and therefore no hemolysis of test cells? 

I believe our cutoff is random, going along with our chemistry laboratory cutoff.

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3 hours ago, Byfaith said:

We have always used a cutoff of 50mg/dl hemoglobin concentration (Visual color chart).  We use EDTA tubes and Provue analyser.  Are we overdoing it?  Sounds like many places take everything but gross hemolysis, and even those on an urgent case.

I don't reject samples based on visual inspection, I let ProVue decide.  If ProVue can't read the gel card and if the user can't read the card manually, then we reject the sample and get a new sample.

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The Echo won't like a specimen w/ hemolysis at 3-4+ when graded. That's actually quite a lot of hemolysis, so the specimens we reject for hemolysis are few and far between. The majority of our hemolyzed specimens tend to come from IV starts collected by nurses - they are 'supposed' to be saving us time by collecting specimens that way.

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OK.  But for a possible hemolytic transfusion reaction, do you not have to compare plasma pre- and post-transfusion?  We do (maybe its not required?)  If the pre-transfusion specimen starts out hemolyzed, it's not going to matter that your automated analyzer completes it's testing-- the comparison in the case of a workup would be useless.

And I would agree with those who say it is generally bad lab practice to test hemolyzed specimens for any test.  It indicates that there was a rough draw and the quality of the specimen is questionable for many analytes.  

Scott

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Sorry Scott, but there are a myriad of tests available do demonstrate a haemolytic transfusion reaction that are far more accurate than haemoglobin in the plasma, which may be present for a large number of reasons other than a "rough draw".  To give but one example, I would defy even a very skilled phlebotomist to produce an absolutely "clean" sample in the case of a patient with a very strong "cold" auto-antibody, either pre- or post-transfusion.

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2 hours ago, Malcolm Needs said:

Sorry Scott, but there are a myriad of tests available do demonstrate a haemolytic transfusion reaction that are far more accurate than haemoglobin in the plasma, which may be present for a large number of reasons other than a "rough draw".  To give but one example, I would defy even a very skilled phlebotomist to produce an absolutely "clean" sample in the case of a patient with a very strong "cold" auto-antibody, either pre- or post-transfusion.

Oh, I agree Malcolm.  And we do accept slightly or even moderately hemolyzed samples in our lab, depending on the test.  My point was, in the case of a possible transfusion reaction, when one has to document pre- and post- appearance of the plasma, it is completely pointless if the pre- specimen is hemolyzed to begin with.

Anyway, this thread seems to be more concerned with automated ananlyzer requirements regarding hemolysis.   I have found a few papers online, but it seems like they are only verifying that analyzers only begin have problems with at least moderate amounts of hemolysis.  Not being experienced at all with what Byfaith is working with, I would guess that if the manufacturer doesn't have a problem with lesser hemolysis, they may be nothing to worry about.

Scott

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4 hours ago, SMILLER said:

OK.  But for a possible hemolytic transfusion reaction, do you not have to compare plasma pre- and post-transfusion?  We do (maybe its not required?)  If the pre-transfusion specimen starts out hemolyzed, it's not going to matter that your automated analyzer completes it's testing-- the comparison in the case of a workup would be useless.

And I would agree with those who say it is generally bad lab practice to test hemolyzed specimens for any test.  It indicates that there was a rough draw and the quality of the specimen is questionable for many analytes.  

Scott

Transfusion reaction workup is a whole 'nother animal. If I get a post-transfusion specimen that is hemolyzed, the first thing I do is ask the phleb if the draw was difficult. If it was, I send up someone else to obtain a new specimen. If we can't get a clean specimen, then that information is part of the documentation and taken into consideration with the interpretation of results.

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1 hour ago, SMILLER said:

Not being experienced at all with what Byfaith is working with, I would guess that if the manufacturer doesn't have a problem with lesser hemolysis, they may be nothing to worry about.

Scott

At the beginning of the testing process, ProVue warns the user with a disclaimer displayed onscreen that hemolysis, icterus and turbidity (wbcs, lipemia) may interfere with reading of a sample.  ProVue takes an image of the gel well and does a gray-scale analysis. The presence of turbidity, hemolysis and icterus would darken the image and prevent analysis due to lack of contrast. 

Byfaith was asking if her current criteria is too restrictive and for options for sample rejection criteria when using automated gel testing.  My suggestion was to let the machine determine sample acceptability.  Using a visual color chart comparision process that was probably developed for manual tube testing ignores the machine's capability to do sample rejection that is more consistent and appropriate for the machine.

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On ‎7‎/‎16‎/‎2019 at 2:29 PM, Byfaith said:

There is older literature referring to the concept of hemolysis as a positive reaction interpretation.  I believe this is relavant only to tube testing.  There is also the fact that using EDTA samples complement does not come into play and therefore no hemolysis of test cells?  

I believe our cutoff is random, going along with our chemistry laboratory cutoff.

Yeah, we're kind of the same. In terms of standard T/S testing and the cutoff for acceptability, we just throw it on our IH and if it doesn't like the sample it's just done manually. Usually the contrast distinction chromatically is the problem that triggers a rejection/difficulty in testing via machine.

Only when there's hemolysis in a post-transfusion rxn specimen is another redraw requested...

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15 hours ago, Ward_X said:

Yeah, we're kind of the same. In terms of standard T/S testing and the cutoff for acceptability, we just throw it on our IH and if it doesn't like the sample it's just done manually. Usually the contrast distinction chromatically is the problem that triggers a rejection/difficulty in testing via machine.

Only when there's hemolysis in a post-transfusion rxn specimen is another redraw requested...

Except once you have a post- specimen during a possible reaction situation, you cannot go back in time to redraw the original hemolyzed specimen to do a visual comparison.  But like Malcolm pointed out, this is a minor part of the workup anyway compared to other tests (first and foremost, the post- DAT!)

Scott

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