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Monitoring Factors after Plasma Administration

From “japgi.” Hi! I’d like to get some information (if possible a reference) on this clinical situation. If a patient with an uncharacterized bleeding disorder has been transfused plasma or cryoprecipitate in an emergency setting, how soon afterwards can one do a coagulation screen to avoid the results from getting compromised by the transfused factors?
Hello, and thank you for your question. The answer depends upon the half-lives of each of the coagulation factors. For instance, factor VII deteriorates to half its original activity in 6 hours, factor VIII in 12, and factor IX’s half-life is 24 hours. You may find more detail and the rest of the factors’ half-lives in our audio module, Coagulation Overview, Part 1, and I shamelessly recommend our inexpensive handbook, Marques MB, Fritsma GA,Quick Guide to Coagulation Testing, 2nd Edition, AACC Press, 2009.
Of course, you also need to know the starting point, which involves some guesswork based upon original factor activities available within the product and time of infusion. The most you can achieve with plasma or cryoprecipitate in a person deficient in a coagulation factor or factors, without creating transfusion-associated circulatory overload (TACO),  is 30% activity, so that could be considered your starting point. If your goal is to simply establish which of the factors is deficient, this maximum makes the task relatively easy. Geo.

Comments (2)
Bleeding Disorders
Jul 25, 2012 6:06pm

I would also suggest that the answer also involves what ques
I would also suggest that the answer also involves what question you are trying to answer. Is it to see if the transfused product is correcting the abnormality in vitro? Do the coags straightway. Or is to to determine what the patient’s baseline factor levels are, in which case you would assay when patient has recovered from the current bleeding crisis and whatever might have precipitated it. The latter would be performed much later than the time suggested by the factors’ half lives.

Jul 12, 2012 11:39pm

Thanks George.
Thanks George.

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