Screening Assays

Correction for HCT >55%

Joan Chapman sent this question. Our institution corrects for HCT greater than 55% for routine and special coagulation assays. It has been our observation, however, that occasionally a patient sample will have a normal PT and PTT in spite of a high crit. We have had a policy that states if the PT and PTT […]

Screening Assays

Promacta and Brown Plasma

From John Mitsios, MD at Cornell. Hi George! I had a question regarding the effects of eltrombopag (Promacta®, a TPO stimulating agent), which is typically given to patients with immune thrombocytopenic purpura (ITP), on routine coagulation assays. The reason for this question is that it has been observed in some patients that at high doses the plasma […]

Bleeding Disorders

Pre-surgical Screening Reprise

I’d like to draw your attention to some recent responses to the November 8, 2013 post by Jeanne Isabel entry about pre-surgical screening.

Screening Assays

Factor VII Padua Mutation

As a followup to the July 30 Discordant PT Results, George presented this problem to a colleague in the booth of one of the major hemostasis materials distributors in the Clinical Laboratory Expo, thereby “spoiling his day.” Nevertheless, he had the answer by days’ end, confirming the response posted by Dr. Vadim Kostousov. This was further confirmed […]

Screening Assays

Discordant PT Results

George is attending the annual AACC meeting at McCormick Place in Chicago. A colleague described a puzzling case in which a patient has a prolonged prothrombin time (PT) using a 1.3 ISI thromboplastin reagent (Stago) and a normal PT when using Dade (Siemens) Innovin. The findings are consistent on repeat split specimens, the PTT is […]

Screening Assays

Hyperglycemia and Prolonged PTT

From “BJ:” I recently cared for a 60 yr old type 2 diabetic in hyperglycemic hyperosmolar state. Initial serum glucose 960. The partial thromboplastin time (PTT) was initially 78 seconds without clear reason. The international normalized ratio (INR) was 1.4. The prothrombin time (PT) was not initially checked. I felt that the value was likely […]

Screening Assays

More on Shortened PTT

From Anita Elledge, MT (ASCP), blood bank/coagulation supervisor, Sierra Vista Regional Health Center, AZ: Our coagulation testing is done on a Stago Compact instrument. The linear range is 20–200 s for the activated partial thromboplastin time (APTT, PTT). We have a policy that any PTT result <22 s must be redrawn, not just rerun the same sample, […]

Screening Assays

Pre-Surgical Screening

Prof. Jeanne Isabel, Medical Laboratory Science Program Director, Northern Illinois University, forwarded the following question, posted to the American Society for Clinical Laboratory Science Consumer Forum: “We run prothrombin time assays with international normalized ratios (PT/INRs) on most all patients pre-procedure regardless of whether they take Coumadin or heparin. I have done some research and this is the […]

Anticoagulant Therapy

Ferritin and Prolonged PT/PTT?

From Natalie Shorey, Stago, Inc. Regional Manager, Sydney, Australia: This clinical case & related question came from the scientists at St George Hospital, one of our teaching hospitals here in Sydney. It prompted some discussion when I put it to other scientists, withour coming to any conclusion so I thought I’d pose the question to you. A patient […]

Coagulation Factors

Sodium Citrate: 3.8%?

A contributor asks, “has sb reported shorter clotting times when using 3.8% (0.129M) sodium citrate tubes than 3.2% (0.109M) tubes? literature and the logic says the opposite.” Hello, and thank you for your question. I’m unsure of your reference to “sb,” however I agree that it is logical to presume that the 3.8% sodium citrate […]

Screening Assays

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George Fritsma is a medical laboratory scientist, educator, and author. George holds faculty appointments with Rutgers University and Michigan State University, and is a member of the International Society on Thrombosis and Hemostasis, American Association of Clinical Chemists, and American Society for Clinical Laboratory Science.

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