Specimen Management

Adjust D-D for HCT?

From Michael Suter, MT (ASCP) SH Senior Clinical Scientist, Hematology, Peace Health Laboratories, Springfield, Oregon. George, I am curious about your thoughts on how to best address the effect of high hematocrits (HCTs) on the quantitative latex D-dimer assays such as the Stago D-Di test. With high HCT samples, there is a relative decrease in plasma causing […]

Adjust Citrate in Severe Anemia?

From Barbara Caufield, Good Samaritan Hospital: We adjust the Na citrate volumes in coagulation tubes when the hematocrit (HCT) is > 55%. Do you recommend correcting for low HCTs? Can you tell me what formula you would use for a low HCT? At what HCT percentage do you recommend adjusting the sodium citrate? Thank you! Hello, Barbara, […]

Specimen Management

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

Hemostasis Specimen Management

I am trying to find a chart or article that tells how long plasma is good for hemostasis testing. The question has arisen about fresh samples and frozen samples. We often get requests for add-on tests and need to know how long is too long. Do you know of a resource that will provide this […]

Specimen Management

Overfilled Tubes

Here is a question originally posted November 4, 2011 that did not attract discussion at the time: I received a note from David Chance, Good Samaritan Medical Center, Corvallis OR, commenting that, unlike underfilled coagulation specimen (blue-closure) tubes; overfilling tubes, unless clots are present, does not affect coagulation results. Overfilling may occur when a specimen is […]

Specimen Management

Specimen Freezing and FVII Activation

Oiginally posted on October 25, 2011. From Kim Kinney at Indiana University (formerly Clarian) Health Center: Hi George, Even though I am not in coag much any more I still get a ton of questions. One of our TC’s was questioning our storage of PT/INR specimens. We follow the current recommendations of room temperature for 24 hours. […]

Specimen Management

Last Word on ACD Tubes for Platelet Satellitosis

Actually, nothing on this site is the last word, however I contacted Dennis J. Ernst, MT (ASCP), Center for Phlebotomy Education, about Donna Kaiser’s 4/5/13 acid-citrate-dextrose (ACD) tube question. Dennis’s response is: “Nice to hear from you. I haven’t heard anything about the use of ACD tubes in this context. I wonder if a tube manufacturer would shed […]

Specimen Management

ACD Tubes for Platelet Satellitosis

From Donna Kaiser, St. Joseph Health System: I was wondering if you have any information on using acid citrate dextrose (ACD) tubes for EDTA platelet clumpers. I have heard they may work better than the sodium citrate tubes especially for oncology patients. If so, are Sol A or Sol B tubes being used and is there a […]

Specimen Management

High HCT and PT, PTT, and D-dimer

From Barbara Robinson, MT (ASCP), Children’s Hospital of New Orleans, If a sample is tested for D-dimer, prothrombin time (PT) and partial thromboplastin time (aPTT, PTT), and the anticoagulant in tube has not been adjusted for high hematocrit (HCT = 60.8%), what tests would be invalid, and how would results be affected? Hi, Barbara, and thank you […]

Screening Assays

Bleeding After CABG: Heparin?

Here is a puzzling case sent by Crystal Azevedo: Hi George! I have a question for you from one of my pathologists. 24 hours after an uneventful coronary bypass procedure a 51 kg patient developed acute hemorrhage. A post-protamine thromboelastogram (TEG) on the day of surgery was completely normal. At the time bleeding occurred, the patient […]

Anticoagulant Therapy

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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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