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Reprise: What About PT Owren?

Reposted from November 28, 2011 from Robert Löfvenmark, MediRox AB, Nyköping, Sweden: Hello, I am from Sweden and I am curious on the international differences in use of PT. Two PT methods are predominantly used today: PT Quick, developed by Dr Armand Quick, 1935; and PT Owren, by Dr Paul Owren 1951. Most parts of the […]

Anticoagulant Therapy

PTT Mix Prolonged Beyond Patient PTT

From “Danagah” (originally posted February 23, 2012): Hi, George, have you seen the situation when, in the 1:1 immediate mix of a partial thromboplastin time (PTT) mixing study, the PTT is longer than the patient’s initial PTT? The patient does not appear to be on heparin (data to follow): Patient PTT: 39.0 sec Normal pool: 30.9 sec 1:1 […]

Hillary Clinton’s Thrombosis

Here is an audio summary of Secretary of State Hillary Clinton’s Cerebral Sinus Venous Thrombosis episode by Samuel Goldhaber, MD

PTT >180 seconds

From Renee Nutting: Is a PTT of >180 seconds always the result of heparin contamination or would such a result ever be medically desirable for a patient? Hello, Renee, and thank you for your question. A partial thromboplastin time (PTT) of >180 seconds, or one at the limit of instrument measurement, is likely an indication of […]

Anticoagulant Therapy

Reprise: Switching to Anti-Xa

Reviewing Sue Bergs‘ March 23, 2012 post asking, How Many Use the Anti-Xa?, I noticed the comment appended by “Istano” asking for data on switching from PTT to anti-Xa heparin assay for routine heparin monitoring. My answer was somewhat incomplete, so I thought I should connect this question with Marisa Marques, MD‘s June 20, 2012 question, Do You Use […]

Anticoagulant Therapy

Thrombocytopenia: Reprise

I am reconstructing previous Fritsma Factor posts subsequent to the crashes we experienced in November and December and came across an April 12, 2012 communication from an individual who has non-symptomatic thrombocytopenia with giant platelets. I suggested this could be one of the MYH9 mutations such as May-Hegglin anomaly. I post this link now, hoping to attract comments from some […]

Platelet Function Testing

LA Testing When PTT is Normal?

Hello Geo, I have a question about lupus anticoagulant (LA) testing. Before I go off and tell people wrong I thought I would run this by you. Situation is, we have physicans who want to run antiphospholipid syndrome panels on patients who have a history of having a clot (one time usually). The activated partial […]

Lupus Anticoagulant

Tube System and Heparin

The subject of tube system hemostasis specimen delivery originally appeared on theMedlab_L list, and I asked Linda Stang, Lab Scientist in Special Coagulation at theUniversity of Alberta Hospital in Edmonton for permission to share her Medlab_Lcomment. She wrote, “Our hemolysis rate for those patients is much higher and we are engaging in a plan to figure it out. The […]

Specimen Management

Specimen Tube “Head Space” and pH

A colleague asked about an issue with “head space” and surface area in sodium citrate (blue-closure) tubes causing changes in pH with the changes becoming more profound the longer the tube is stored. This then affects test results. My friend had not heard of this before although he knows there are pH changes associated with […]

Specimen Management

VerifyNow Platelet Function Screen?

Attached to the December 28 post, “Platelet Function Testing and the Bleeding Time” with the AC Ivy story was the question, “Is the Accumetrics VerifyNow aggregometer useful for screening patients for inherited platelet function disorders?” Yes, I consider the VerifyNow assay effective in screening for platelet function defects, like storage pool disorder or platelet secretion disorder (aspirin-like syndrome), however […]

Antiplatelet 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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