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Unexpected Technical Difficulties

We had some unexpected technical difficulties today – we hope this didn’t inconvenience any of you. We’re back up and running now and don’t expect to have any more issues. As always, thanks for posting and keep asking great questions!

Siemens Response Re PTT Control Drift

From Siemens Manager Carol Shearer: To help you with your quandary….It looks like Tara really followed our process. What is recommended by Siemens is for the customer to contact Siemens to file a complaint about the reagent or control. We log and file all calls and tally the number of calls by lot number of reagent or […]

Quick Question: PTT-based Phospholipid Neutralization

This question turned up some surprises: When performing the PTT-based phospholipid neutralization procedure, what limit do you use to confirm lupus anticoagulant? a. ≥ 8 seconds’ difference between pre- and post-PTT: 8 (33%) b. Locally computed difference in seconds between pre- and post- PTT: 5 (21%) c. Ratio ≥ 1.2 between pre- and post-PTT: 4 […]

Clot Connect, a New Site

I’ve just updated our Additional Hemostasis Resources page with several additions, including Clot Connect, a new site moderated by Stephan Moll, MD, University of North Carolina at Chapel Hill Hemophilia and Thrombophilia Center, partnered with the US Centers for Disease Control. Please browse our links, and especially take a look at Dr. Moll’s new page.

PTT Controls Drift Upwards

From Mary Ann Tara: Is there a way to validate partial thromboplastin time (PTT, APTT) results over the shelf life of a particular lot number? We recently experienced a serious problem with deterioration over time of our Actin FSL reagent. It initially was seen in a drift up and out of range for our abnormal […]

Specimen Collection for PFTs

In case you missed in in the sidebar, we’ve had an interesting

PT Specimens: Centrifuged or Uncentrifuged?

From “Cassip:” My laboratory does quite a bit of outpatient clinic work. The lion’s share are prothrombin times. We store these at room temperature, but they can be delayed up to 8 hours before testing. I have heard that samples that are held uncentrifuged until testing preserves integrity better than those that are centrifuged immediately […]

Factor XIII: Urea Solubility

From Carol Gizzi: I am trying to find a procedure for the factor XIII urea assay. Hi, Carol, I found the procedure in a book Dr. Donna Corriveau and I published in 1988: Corriveau DM, Fritsma GA. Hemostasis and Thrombosis in the Clinical Laboratory, Lippincott, 1988. It is attached here: factor-xiii-urea. You may also want to click here and check […]

Protein C and Protein S Deficiency

Here is a question I answered yesterday for the ASCLS Consumer Forum. It discusses a common problem, so I have reproduced it here: Should Lovenox be used for someone with a protein C and protein S deficiency when there is a coumadin hold related to a procedure scheduled? My answer: Your physician may choose to […]

Unexplained Prolonged PTT

From Enriqueta Coll: Dear George, I work in a small laboratory. In some pre-op patients without a history of bleeding, we have had results of partial thromboplastin time (PTT) prolonged between 5–10 seconds’ differences patient vs. control when using Actin, but normal when using C.K. Prest. We perform all tests using a Stat 4 coagulometer. […]

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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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