All Posts

Local INR Calibration: Still a Dream

From Julie Tange, Developmental Technologist at Mayo Medical Laboratories: Hi George, our lab recently brought up calibration of the INR/ISI again. I know this was a hot topic a couple of years ago and CLSI came up with a document providing guidelines. I had heard at that time that a couple of companies were developing calibrator […]

Trinity Bio-Tech Coagulation Business Sold to Stago

Trinity Bio-Tech of Dublin, Ireland announced Thursday, March 11 the sale of their coagulation business, including manufacture of their Destiny Max coagulometer to Diagnostica Stago, Incorporated of Asnieres, France.

Assay for Fitzgerald Factor

This arrived Wednesday from Mr. Peter Clement, MLS Student at Brigham Young University in Provo, Utah: I am currently studying to become a Medical Laboratory Scientist. My professor is Dr. Shauna Anderson at BYU. I asked today if she had ever visited a website called Fritsma Factor, to which she replied yes and she added that […]

Case Study: Prolonged PTT

Hi George, I have a 33 yo HIV positive non-compliant female patient with chronic kidney disease. Labs: PT: 13.4 (11.7-14.2) PTT: 47 (23-33) FIB: 300mg/dL D-DIMER: 1.61 FEU Where do I go from here? Richard Larsen, US Army Hi, Richard, I suggest your next step is a mixing study for the prolonged PTT. This will […]

Anti-Xa Validation Request

If you can assist Dr. Pena, please respond via the “comments” section below. This was sent through Dr. Marisa Marques, University of Alabama at Birmingham Hospital: Dear Marisa, how are you? I work for Norton Healthcare in Louisville, KY. We are trying to set up our assay for anti-Xa for low molecular weight heparin. We […]

Applicator Sticks: How to Detect Clots

From Bill Chamlee at the Cleveland VA: Hi George, I stumbled onto your site while researching the new lower potency heparin/therapeutic range issue. I was interested in your quick question about checking for clots. I don’t do any of the four choices you list. I use two applicator sticks to check for clots after centrifuging […]

Switching to Fondaparinux

I’m a registrar in an ICU at Menofyia University, Menofyia, Egypt. We have been thinking about using the new drug, Fondaparinux. Could you please give me more details about the drug, when to monitor its efficacy (all patients or high risk only?) and how do you use the anti-factor Xa assay; i. e. the kits […]

Heparin Anti-Xa

From Dr. David Floering: Is anyone routinely using heparin anti-Xa assay to monitor heparin instead of PTT? If so, what are the experiences? David Floering, MD Medical Director, Pathology Atrium Medical Center Middletown, Ohio Dr. Floering, thank you for your question. I have several acquaintances who have successfully converted from PTT to the chromogenic anti-Xa […]

Bethesda Titer Formula

Two messages from Beaumont on Bethesda titer calculation: Hi George, I wanted to ask you if you know the formula to calculate the amount of factor inhibitor BU for the classical Bethesda assay. We have been graphing the results on the log log paper. We are working on a new LIS system and would like […]

Collagen Lag Phase Software?

Dear George, We are in the process of getting new software for the lab. I would like to know if there is a formula available for calculating the collagen lag phase (T 1/2) . Our older Chronolog aggregometer does not have this feature. Currently our techs are manually drawing, measuring and calculating it. Thank you, […]

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