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Alcohol and Coumadin

This question comes from the American Society for Clinical Laboratory Science Consumer Information Forum and was forwarded to Fritsma Factor by Prof. Bernadette (Bunny) Rodak of Indiana University. It is modified to mask the identity of the inquirer. “I have been on 5 mg/day of Coumadin for three months following hip replacement surgery and my […]

More on CAP and Mixing Studies

I have a question about the post regarding mixing studies and CAP checklist question 37991. (I have been trying to post this on “The Fritsma Factor” with no success.) I thought CAP question 37991 addressed appropriate plasma for mixing studies. If this is the case, is it appropriate to use lyophilized plasma for mixing? I […]

How to Establish the PTT Therapeutic Range

Hi, George, We survived the validation and are very pleased with our new Beckman-Coulter TOP, but I have an issue with the new PTT therapeutic range we established for unfractionated heparin (UFH). We collected many specimens over time, made sure they were double-spun and froze them at –70°C. Once we had the PTT validated and […]

Controls and Heparin in Mixing Studies

George: We recently had a CAP inspection and had a couple of recommendations that we’re trying to tidy up. 1. HEM 37991 regarding a control for PT mixing studies. We were using what we considered to be the normal control but were told to order the Dade Control N. I’ve ordered and just want to […]

Snakebite and D-dimer.

I am trying to discontinue the fibrin (ogen) degradation products (FDP) assay in favor of the D-dimer. I have read and used several of the posts here as references and reasons for this decision. A recent question from an ER physician has me doing some further research and I need your help. What about snake […]

The Vytorin Controversy and Surrogate Markers

The big news at the American College of Cardiology annual meeting in Chicago March 29-April 1 was the controversy caused by the ENHANCE (Effect of Combination Ezetimibe and High-Dose Simvastatin vs. Simvastatin Alone on the Atherosclerotic Process in Patients with Heterozygous Familial Hypercholesterolemia) trial result, essentially ending a 2 billion dollar annual market overnight. Vytorin, […]

Patient Self-testing

David Garcia, MD, president of Anticoagulation Forum reports the US Centers for Medicare and Medicaid Services (CMS) has drafted a decision to generalize patient home Warfarin monitoring. In-home PT/INR testing reimbursement has been confined to patients with mechanical heart valves. Pending a final ruling this fall, reimbursement will be extended to self-monitoring of Warfarin for […]

Protein C and S Immunoassay

I’ve never understood why protein C and protein S immunoassay results are reduced in Warfarin therapy. Because Warfarin reduces gamma-carboxylation of protein C and protein S glutamic acid units, we expect there to be reduction in activity assays but it turns out that immunoassay results are also proportionally reduced. Stephen Duff of Precision BioLogic asked […]

Discard Tubes and Butterfly Sets

I’ve been seeing several posts in Medlab-L about the need for a discard tube when collecting hemostasis specimens using butterfy needle sets. The air within butterfly set tubing occupies approximately 0.5 mL and reduces first tube collection by that volume. For a 3.0 mL total collection tube, this is a 16% reduction in total final […]

Paraoxonase (PON1)

Here is an interesting message about paraoxonase from colleague Dan Southern. “Have you ever heard of paraoxonase? The article below, out of Cleveland Clinic, makes me want to be tested yesterday.” “Cleveland Clinic Researchers Show Strong Relationship Between HDL-Associated Protein And Protection From Heart Disease Risk” Findings Appear in Special Genetics in Medicine Issue Published […]

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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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