SMILLER

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

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

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

LOL! I have the same problem with many of these articles! (More than you and others here I think!) Scott

Interesting. One question Malcolm, up until reading this report from our reference lab (most of which could be written in Greek and I would not understand it less) I had never heard of the DAU partials. I saw in one paper that the DAU-0 is thought to be the "primordial" example of this particular clade (if you want to call it that), and that DAU-1 through 5 are further variants on that. This seems to go against the current distribution of the various DAUs (D - African Observed), where DAU-0 is found in Europeans, and all of the others are found in Africans. Would this mean that the DAUs started in Europe and then somehow spread to Africa where they further differentiated? It seem backwards somehow. Thanks, Scott

Truth is important, but the appropriateness of such a statement should be measured by its usefulness. Scott

Results of our reference lab testing on this patient makes him out to be a partial-D, specifically DAU-0. (Nothing about an anti-LW, which is where I was going.) They note that "patients with a partial RHD*DAU0 allele have not been reported to make anti-D, therefor, this patient's reported anti-D is most likely autoimmune." The Genotype is: RHD*DAU0-ce(48C) / RHD*03N.01-ceS. Also they found that the patient is homozygous for the "Duffy null promoter FY*02N.01-67c SNP". Whatever that is. The report seems very comprehensive with lots of information, including references. Scott

There is a catch-22 there for the clinicians when they think an otherwise stable patient needs a transfusion If you think the patient needs blood, just one unit should be adequate; and if only one unit is ordered, why transfuse at all? In general, we require a recent Hgb before routine transfusions. Scott

Any study that challenges the status quo should be met with caution (but NOT with derision I think!) This is an admittedly only a pilot study that, like others before it, suggests more robust studies need to be done. I think it is interesting though because it is from a different standpoint -- that of a vascular specialist or a perfusionist. Scott

Similar to David, above. When a unit is ordered, it is ordered for transfusion. We have exceptions for OR, atypical antibody patients, and things like massive transfusion protocols. Scott

My sense of the "advantages" of lower hemoglobin levels is not that patients thrive because of lower hgbs, but rather that, in many cases, they can thrive with fewer transfusions. Scott

I believe the point of the post-transfusion H&H in this discussion is more to avoid giving another (perhaps) unnecessary unit. I think the consensus is that for a Hgb to stabilize fully, you want to look at it at 24 hrs. However, the H&H done an hour or even a half hour after a transfusion finishes is going to be close enough to make clinical decisions like whether to transfuse another unit. Scott

An interesting look at low verses high triggers for certain surgical patients. http://www.bloodjournal.org/content/early/2019/03/11/blood-2018-10-877530?sso-checked=true Scott

Pretty much our approach here in the US. Hgb is checked after every unit for the more routine transfusions of pRBCs. Scott

The book by Carreyrou is pretty good. Holmes and Balwani go on trial next summer. Scott