Quick Question Archive

Quick Question Results: Bethesda Titers

The results of our latest Quick Question are in with 87 responses.. How does your laboratory measure factor inhibitors? Standard Bethesda assay: 33% (26) Bethesda titer using buffered pH 7.4 pooled normal plasma: 9% (8) Nijmegen Bethesda assay using factor-depelted plasma as diluent: 9% (8) CDC modification of Nimegen Bethesda assay: 0% (0) Bethesda chromogenic […]

Bleeding Disorders

PT and PTT Reference Interval

Here are the results of our latest Quick Question: How many normal subject specimens do you collect to establish a PT and PTT reference interval? a. 240: 7 votes, 3% b. 120: 79 votes, 35% c. 30: 51 votes, 23% d. 20: 79 votes, 35% e. Other: 9 votes, 4% Comments excerpted from Fritsma GA. […]

Quick Question Archive

Subjects in Reference Interval Study

Mona Murphy, Pathology Laboratory, Lewiston, ME reports using 20 males and 20 females in a normal range study.

Quick Question Archive

Reference Intervals: December QQ

We’ve just posted a new Quick Question, and have already received this response from Heather DeVries, Indiana University Health. I just logged in and saw the new Quick Question. I am excited to be the first to respond! Of course my answer is not simple. As a system, we use close to 300 normals to […]

Quick Question Archive

What Result Triggers a PTT Mix? QQ Summary

Here is the summary of our October-November, 2015 Quick Question, “What PTT value initiates a PTT mixing study in your laboratory?” The question drew 157 responses. Any PTT result longer than the upper limit of the reference interval: 25% PTT result longer than the upper limit of the reference interval pending physician consult: 18% PTT […]

Mixing Study Correction Survey

Here are the results of our July, 2015 mixing study correction Quick Question survey: When performing PTT mixing studies using normal control plasma (NP), what criterion do you use to define correction? A. Mix results within 10% of NP result—60 votes, 32% B. Mix results within 5 seconds of NP result—20 votes, 11% C. Mix […]

Quick Question: Mixing Studies

From Herb Crown, St. Louis University Hospital Coagulation Reference Laboratory: George, for the mixing study cutoff question, I answered “other” because, as I have written on a number of occasions, we have a reference range for our control and patient mixing studies that is different than our routine aPTT. I hope I did not confuse […]

QQ Responses: Platelet Function

Here are the results of our November, 2014 Quick Question: What platelet function test do you use for platelet function disorders and/or for aspirin and clopidogrel efficacy? a. Siemens PFA-100: 35%, 24 votes b, Accumetrics VerifyNow: 25%, 17 votes c. Light transmittance aggregometry: 18%, 12 votes d. None: 10%, 7 votes e. Whole blood impedance […]

Antiplatelet Therapy

Mixing Studies: What Constitutes Correction?

This week George posts a new Quick Question to learn how we define PTT mixing study correction. Here is how the question will look: When performing PTT mixing studies using normal control plasma (NP), what criterion do you use to define correction? a. Mix result within 10% of NP result b. Mix result within 5 […]

Quick Question: Platelet Function Poll

From Scott Miller at St. Mary’s of Michigan: Just a note. We use both the PFA-100 and the Verify Now for platelet function testing. I am unable to get the poll to accept more than one response. Scott Thank you, Scott, we will add your response to the total when we publish the results. Geo

Platelet Function Testing

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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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