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A Summary of Mixing Studies

George: I was looking at different coagulation methods, possibly doing factor testing and mixing studies. We are looking at various instruments, one being the ACL TOP. I was wondering if there was a list of the specific disease states and the correction factors involved. For example, if a specimen was corrected by the addition of […]

Fresh Frozen Plasma

For as long as I can remember, the transfusion service has released fresh frozen plasma (FFP) to treat emergent or chronic bleeding secondary to liver disease coagulopathy, vitamin K deficiency, DIC, warfarin overdose rescue, or single factor deficiencies for which no single factor concentrates were available; prothrombin, V, VII, X. FFP is supernatant plasma expressed […]

PT Test Volume

Here is a message from Jennifer at the University of Tennessee at Memphis, who is doing a research study about utilization of the INR. Jennifer would like to document the frequency of PT tests ordered daily, nationwide. Please send a reply giving your laboratory’s volume so she can extrapolate to estimate a nationwide volume. Thank […]

New Method Validation

Kim Kinney at Clarian brings question only when she has a really tough problem, as she can resolve most coagulation issues that come along. She is converting her central lab and a number of satellite labs from MDA to Beckman-Coulter Inc. (BCI, TOP) instrumentation, and most recently is moving her factor V and VII activity […]

Critical INR Value

We’ve posted a new quick question sent by Kim Kinney of Clarian Laboratories in Indianapolis. I look forward to seeing your answers, and encourage you to submit quick questions for a survey also.

Quick Question: Reporting the HIT Immunoassay

Our current “quick question” was provided by Dr. Michael Blechner: “When performing ELISA testing for heparin-induced thrombocytopenia (HIT), how do you report the results? Answers from twenty reponses are below… a. Positive, negative, equivocal, confirmed by saturating heparin dose: 8 (40%) b. Positive, negative, equivocal, unconfirmed by heparin: 5 (25%) c. Positive, negative, equivocal with […]

Computing the INR

Here is a question from Joseph A. De Vito In reading an article, Quote: The INR is a standardized number and is calculated from the patient PR, the normal range for PT, and the sensitivity of the reagent used. Please explain to me the following: (1) The patient PR (2) Normal range for PT (3) […]

Warfarin “Resistance”

I’ve had several discussions with Marisa Marques, MD, my friend and colleague in Laboratory Medicine at the University of Alabama at Birmingham about “warfarin resistance,” as she was managing two deep vein thrombosis patients, one of whom required warfarin at 25 mg/day and one at 35 mg/day. We were looking for a polymorphism associated with […]

More on Warfarin Sensitivity Screening

On October 30, 2007, under the title, “Anticoagulant Forum and CYP2C9,” Kim Kinney and I briefly addressed the polymorphisms that affect warfarin dosage. In August, 2007 the FDA had begun requiring a box on the warfarin label recommending genetic screening prior to dosing as a patient safety measure. Here is a little more detail… Three […]

Quercetin

As a member of the American Society for Clinical Laboratory Science (ASCLS) I have the opportunity to answer lab-related patient questions posted on the ASCLS Consumer Forum. This is a valuable service, first created by Dr. Susan LeClair at the University of Massachusetts in Dartmouth, that attracts an average of 100 questions a day and […]

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

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