All Posts

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 […]

Bob Malia

From Dr. Steve Kitchen: We have just learned the very sad news that Bob Malia has passed away. I don’t have any more details just now but will come back with addresses, etc. for any messages and details of arrangements when I have these.One of a kind and an inspiration to many of us in the field of […]

More on Age-Adjusted D-dimer Limits

I’d like to draw your attention to the numerous and insightful responses to Sylvia Stacy‘s question about applying age-adjusted D-dimer limits to venous thromboembolic disease diagnosis, especially Dr. Giuseppe Lippi’s entry with a link to his brief questionnaire, which he intends to keep open through February, 2015. Let’s give Dr. Lippi as many responses as possible.

Clotted Specimens

I recently received a message from a local colleague who has received complaints from the nursing department when rejecting clotted coagulation specimens. The problem occurs with both citrated blue-closure and EDTA lavender-closure tubes. A few of the nurses are convinced the laboratory is storing the specimens too long before testing them, thus allowing them to […]

Specimen Management

Coumadin and Factor Half-lives

I received a question recently about Coumadin (warfarin) therapy and coagulation factor half-lives. Coumadin reduces the normal carboxylation of the glutamic acid γ-carbon. There are 12–18 glutamic acid units near the amino terminus of the vitamin K-dependent factors II (prothrombin), VII, IX, and X. When vitamin K-catalyzed γ-carboxylation becomes suppressed, these coagulation factors are unable […]

Anticoagulant Therapy

Mixing Study: LA Effect?

Hello Mr. Fritsma! My name is Agustin Rodriguez and I am a haematologist from Spain. I have a question for you, if you are so kind to ansxwer it: I have a patient with a lupus anticoagulant. His PTT (aPTT) is 46 s; normal aPTT is 30 s in my laboratory. The inmediate mixing study 1:1 with […]

Lupus Anticoagulant

Age-adjusted D-dimer Limit?

Hi George, I am wondering if anyone is using the age-related D-dimer cutoff for the emergency room based on the ADJUST-PE study? We use Innovance D-dimer reagents from Siemens on the BCS XP analyzer. Our ER physicians are very impatient for us to allow them to use this age-adjusted cut-off, but we have reservations due […]

Favorable FDA Edoxaban Vote

According to an October 30 Medscape post, Edoxaban (Savaysa, Daiichi-Sankyo) received a favorable vote, 9–1, in favor of release for once a day treatment at 30 and 60 mg to prevent non-valvular atrial fibrillation ischemic stroke. Edoxaban was found non-inferior to “in control” Coumadin in patients with mild to moderate renal impairment, but its performance in […]

Anticoagulant Therapy

Vascular Access Device Collection

From Nancy Fabbrini: We have a patient on an argatroban bridge to warfarin. He is a very difficult draw so the service has been drawing blood from the central access device. They have been withdrawing 20 mL of blood before drawing the tube for coagulation testing. Is that sufficient, i.e. do the same “rules” for a […]

Specimen Management

Load more

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.

Cheat Sheets from George

Quick Question