Specimen Management

Discard Tubes for Heparin?

From Dennis Ernst, Center for Phlebotomy Education, Inc: I am chairing the CLSIDocument Development Committee on the venipuncture standard revision. At today’s web meeting the question came up about the necessity for discard tubes on heparinized patients. It’s been widely reported that discard tubes are not necessary, and haven’t been for some time. However, it came to our […]

Anticoagulant Therapy

Tube System Effect on Platelets?

From Gnaesh Lyer, Florida Hospital: Have you done any correlation studies for Plavix and aspirin if the tubes are sent by tube system from floors rather than hand delivering the tubes? Does the results vary a lot or with in acceptable range? Thanks. Hello, Gnaesh Lyer, and thank you for your question. I know of no studies […]

Platelet Function Testing

In Vivo Hemolysis

Irene Regan writes that despite doing major literature searches there seems to be no consensus regarding what coagulation results should be released when there is a suspicion of in vivo hemolysis such as in disseminated intravascular coagulation (DIC), when the samples are grossly haemolysed. Currently, Irene issues a fibrinogen (Clauss) and in this case she generally […]

Bleeding Disorders

Coag Specimens on Ice

From our frequent contributor, Kim Kinney at Indiana University Health Pathology Laboratory: Merry Christmas all! George, this may be an old topic, but I am getting some push back from our off-site coordinators. Coagulation samples sent on ice: I have always thought that the current literature stated that iced coag tubes could activate factor VII and potentially shorten […]

Specimen Management

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

Rivaroxaban Specimen Stability

From Soakimi Pouhila, Auckland District Health Board, New Zealand: Hi George, any ideas on the stability of rivaroxaban in citrate samples? Hello, Soakimi Pouhila, and thank you for your question, which sent me to PubMed to see if anything has been published on rivaroxaban stability. My search was fruitless, so I’m posting your question to attract comments […]

Anticoagulant Therapy

Hepzyme Interference?

From Crystal Azevedo, “Are there any substances known to interfere with the neutralization of heparin by the Dade (Siemens) Hepzyme product? We recently worked on a patient sample that I am told had absolutely NO heparin in it, yet the PTT decreased from >200 seconds to 89 seconds after treatment. Thanks!” Hi, Crystal, and thanks for […]

Specimen Management

Erratic PTT

George received a note from a colleague who has three separate specimens from a patient with prolonged partial thromboplastin times (PTTs) that further prolong as they stand at ambient temperature over periods of several minutes, for instance, 57s, 151s after 20 minutes, and 174s after 2 hours. Mixing studies consistently correct. They’ve tested them on […]

Specimen Management

Pediatric Collection Tubes

From Diane Belliveau, Catholic Medical Center, Manchester, New Hampshire: Hi George, we have a special care nursury. I am looking for help in specimen handling/volumes for these special patients. Are there any new products for coagulation specimen collections on babies? Hi, Diane, the only 3.2% sodium citrate tube available for low-volume collection, 1 mL, is the Greiner Bio-one […]

Specimen Management

More on “Unexpected DRVVT Results”

Here is a message about the dilute Russell viper venom time assay (DRVVT) for lupus anticoagulant (LA) from international expert Thomas Exner, HAEMATEX, Sydney, Australia: It was a pleasure to meet you at the International Society on Thrombosis and Haemostasis (ISTH) meeting recently. I would like to respond an interesting question raised on July 16, 2013 in your Fritsma Factor website. […]

Lupus Anticoagulant

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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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