Anticoagulant Therapy

POC INRs

From Bob Gosselin: Hey GF, re point of care (POC) international normalized ratios (INRs), assuming that you are collecting a citrated sample for testing, a high hematocrit (HCT) should not matter for a system that employs fingerstick whole blood, since there is no citrate:plasma ratio issue at hand with using whole blood. Viscosity may be an issue […]

Anticoagulant Therapy

ACC

Here is a summary of the just-ended American College of Cardiology meeting in Chicago. It appears there was a lot of attention given to the new oral anticoagulants, especially to dabigatran (Pradaxa), which has been available since 2010 in the US. I’ve been seeing lawyer’s ads on TV recently, 1-800-BAD-DRUG, focusing on Pradaxa. Does Pradaxa deserve this […]

Anticoagulant Therapy

Monitoring Dabigatran with the ACT

George, We are a large public tertiary care hospital in West Tennessee. I am in the special coag lab. We are encountering some problems with patients coming in on dabigatran who need invasive stent procedures. Typically when the cardiologist uses heparin during the catheterization he orders an activated clotting time (ACT) post-procedure looking for a […]

Anticoagulant Therapy

How Many Use the Anti-Xa?

Hi George, I have visited your site a few times in the past and I own your pocket guide book, so I thought of you when I came up with this question. I read in ASCLS Today an article about monitoring heparin therapy using the chromogenic anti Xa assay instead of APTT. Is that standard […]

Anticoagulant Therapy

Anti-Xa Assay With LA Present?

Dear George, I have a lupus anticoagulant (LA) positive patient with recurrent pregnancy loss. She is on low molecular weight heparin (LMWH) with a request for an anti-Xa assay. Will LA positive whether it is interference by LMWH? What is your opinion? Hello, Vilas, the chromogenic anti-Xa heparin assay provides an accurate measure of unfractionated […]

Anticoagulant Therapy

More on PTT Specimen Storage Time

On November 1 I replied to a question from Joe Lamb, Columbus, GA about room temperature storage of specimens for partial thromboplastin time (PTT) assays that are sent to reference laboratories. Joe was concerned that his reference lab claimed PTT results were valid on specimens less than 24 hours old, whereas the CLSI Guideline H21-A5 sets […]

Anticoagulant Therapy

Serotonin Release by Immunoassay?

Dear George, For heparin-induced thrombocytopenia (HIT) serotonin release assay, can serotonin ELISA sensitive to HIT be used? With regards, Vilas Hiremath. Hello, Vilas, always good to hear from you. I had to go to experts, Drs Larry Brace, Edward Hospital in Naperville IL, and Jon Geske, Precision BioLogic Manager of Emerging Technologies & Markets. Here is a reply […]

Anticoagulant Therapy

Fondaparinux Assay

Hi George! Would you happen to have a list of laboratories performing the anti-Xa assay for Fondaparinux (pentasaccharide, Arixtra)? Do you recommend, when calibrating the assay, to use commercially-available material or spiked normal pooled plasma (NPP)? Thanks for your help!! Love this resource that you provide!! Crystal Azevedo, MT(ASCP)SH Hi, Crystal, thanks for your comment. Machaon […]

Anticoagulant Therapy

Quick Question: Heparin Therapeutic Range

On October 21 I posted my

Anticoagulant Therapy

CAP Requires INR Reference Interval

From Dr. John Olson, University of Texas Medical Center in San Antonio: Hello George, Happy New Year! I hope that your holiday was as pleasant for you as mine was for me. I read with interest the brief piece on the reference interval for the INR. When I was at the University of Iowa a number of […]

Anticoagulant Therapy

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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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