Quick Question Archive

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

QQ Results: Overfilled Coag Tubes

From our summer, 2014 Quick Question, What is your policy for managing overfilled coagulation specimen tubes? a. We reject overfilled tubes; results are likely to be invalid. 116 votes, 69% b. We accept overfilled tubes; overfilling doesn’t affect results. 28 votes, 17% c. We never see overfilled tubes. 24 votes, 14% CLSI Guideline H21-A5 specifies that coagulation tubes […]

Quick Question Archive

Quick Question: PTT Mixing Studies

The results of our January-February 2014 Quick Question: Does your laboratory perform follow-up partial thromboplastin time (PTT) mixing studies 24/7? a. No, only during the day shift, 46 (52%) b. Yes, all day and all night, 30 (34%) c. Not at all, we sent them out, 13, (14%) Total votes: 89 Thanks for the response, […]

Quick Question: Measuring Dabigatran

This question was a reprise of an earlier question and attracted relatively few votes, however it added “In-house dilute thrombin time,” which turns out to be used by several laboratories. What assay do you use to measure dabigatran (Pradaxa)? a. Stago’s ecarin chromogenic assay, 4 (31%) b. Standard thrombin time, 3 (23%) c. In-house dilute […]

Anticoagulant Therapy

In-house Dilute TT

Dear George, I greatly appreciate your website and congratulate you on have such a informative and open educational forum. I was wondering if it was possible to add “in-house dilute thrombin time” to the current Quick Question list? Thank you for your consideration. Sincerely, Glen Holloway. Hello, Glen, and thank you for your suggestion. I will […]

Anticoagulant Therapy

QQ Summary: Heparin Monitoring History

Results of our September, 2012 Quick Question: Historically, what assay was used to monitor heparin? a. Bleeding time: 14 (17%) b. Recalcification time: 7 (9%) c. Lee-White clotting time: 51 (63%) d. Thromboplastin generation time: 9 (11%) Participants need to be well-read, or “of a certain age” to answer this one. Bleeding time is incorrect. […]

Anticoagulant Therapy

New QQ: History

Our August and September Quick Question, posted Monday, August 27, is mostly for fun, and will appeal most to our more “seasoned” coagulationists. No wrong answer, just some more right than others! Please indicate the assay most often used before the partial thromboplastin time (PTT) for monitoring heparin.

Quick Question Archive

Quick Question Summary: VWF Activity

Here is a summary of our July, 2012 Quick Question: How do you assay for von Willebrand factor (VWF) activity? a. VWF ristocetin cofactor (VWF:RCo) by aggregometry: 21 (34%) b. Automated VWF ristocetin cofactor (VWFRCo): 21 (34%) c. VWF activity immunoassay (VWF:Act): 15 (25%) d. Collagen binding assay (CBA): 4 (7%) It seems the collagen […]

Bleeding Disorders

New Quick Question: VWF Activity Assays

There’s a definitive article in the June, 2012 JTH that describes the three methods currently available to assay von Willebrand factor activity: ristocetin cofactor (VWF:RCo), collagen binding (VWF:CB), and a monoclonal antibody-based immunoassay (VWF:Act). See Favaloro EJ, Bonar R, Chapman K, Meiring M, Funk (Adcock) D. Differential sensitivity of von Willebrand factor (VWF) ‘activity’ assays to large […]

Bleeding Disorders

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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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