Anticoagulant Therapy

Heparin and Cell-free DNA

Here’s a challenging question from the ASCLS Consumer web forum: “I’m currently on 40 mg of Lovenox daily during my pregnancy. Can that alter the cell-free DNA test in any way? I take my meds at 10 every morning, should i take the blood test after my shot is due? I’m getting different answers from […]

Anticoagulant Therapy

The 100th Anniversary of Heparin 1916–2016

On behalf of Dr. Jawed Fareed, the Loyola University Chicago Office of Continuing Medical Education extends an invititation to the Heparin Centennial Symposium: Scientific and Clinical Developments and their Impact on the Understanding of the Pathogenesis of Thrombosis and Its Management. The conference will be held in the Center for Translational Research and Education on […]

Anticoagulant Therapy

Bangor Presentations

George was in beautiful Bangor, Maine, Monday, September 12, where he provided two presentations for regional medical laboratory scientists, sponsored in part by Dahl-Chase Diagnostic Services. Handouts for George’s talks are provided below. Please click or tap if you would like to have the handouts. Measuring the DOACs, Whatever Happened to the PT and PTT? […]

Anticoagulant Therapy

Rivaroxaban Causes False LAC Positive

George reviewed this question posted to the American Society for Clinical Laboratory Science Consumer Web Forum: “After DVT/PE helped by TPA/heparin and now on Xarelto 4 weeks, my first blood draw shows factor VIII 228%, DRVVT screen 126 sec, confirmation 61 sec, normalized ratio 1.96, but hex phase phospholipid normal range and antiphospholipid normal range. […]

Anticoagulant Therapy

Monitoring DOAC to UFH Change

Correspondence between Lawrence “Lance” Williams III, MD, University of Alabama at Birmingham (UAB) Hospital Special Coagulation Director and Michael Laposata, MD, University of Texas Medical Branch (UTMB) in Galveston Pathology Director: Dr. Laposata, I am curious if you might have some insight on an issue we are having at UAB. We have noticed an increase in patients […]

Anticoagulant Therapy

Anti-Xa Assays and Plasmapheresis

From Joni Noges at Virginia Mason Medical Center: Hi George, our pharmacy is wondering whether anti-Xa levels are affected by plasmapheresis, continuous renal replacement therapy (CRRT), or hemodialysis. For example, should we draw levels 30–60 minutes after the procedures? Thanks. Hi, Joni, I forwarded your question to Lawrence “Lance” A. Williams, II, MD, who manages […]

Anticoagulant Therapy

Does the “Buzzy” Affect the INR?

This is from George’s friend and colleague, Dennis Ernst, of the Center for Phlebotomy Education: A good friend of mine is a pediatric emergency physician, needle-pain expert, and entrepreneur. Dr. Amy Baxter has developed a device you may have already heard of. It’s called the Buzzy. (She was my newsletter’s Mover & Shaker in March.) […]

Anticoagulant Therapy

More on Xarelto and D-dimer

Dr. Jeanine Walenga, Clinical Coagulation Laboratory Director at Loyola University Medical Center added a helpful comment to our April 13, 2016 discussion about Xarelto and D-dimer. Click here to see the discussion and her comment.

Anticoagulant Therapy

Switching From Rivaroxaban to Heparin

Amy Kelley, Dahl Chase Diagnostic Services, asks, one of our hospitals had a patient on Xarelto who came in for surgery. This hospital uses STAGO Xa testing which uses a hybrid curve. The patient’s Xa should drop after 3 days. The patient was put on unfractionated heparin (UFH) while in the hospital. Our question: Should […]

Anticoagulant Therapy

PT and INR Means

Wendy Sutula at Medstar asks about the PT reference interval calculation. Hi, George. Each time we convert to a new lot of PT reagent we run normals and calculate a geometric mean (geomean) to be used in the INR calculation. My question is this. When we are validating or re-validating the PT normal range, is […]

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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