Specimens with Hematocrit >55%

From Michelle Fahs, MT (ASCP), Clinical Laboratory Educator, Mercy Hospital St. Louis School of CLS. George, Do you have any recommendations on how the sample should be collected for coag testing if the patient’s hematocrit is >55%? We have in our policy the formula and procedure for adjusting the amount of anticoagulant in the tube […]

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Specimen Management

Sep 12 2016

george

How Many QC Repetitions?

From Heather DeVries at Indiana University Health. Hello George! In a system meeting recently, our procedure for evaluating new lot calibrator material was discussed. Currently, we require sites to run 5 points of QC after calibrating with a new lot. If the mean of those 5 points is within 20% of the established mean, we […]

Validation

Chilling The NBA Reaction Mixture

From Dr. Mirta Arias: Dear George, Thank you for your answer in the blog. I have another question. Dr. Robinson in ISLH argued that it is good to chill the post 2 hour/37°C 37 incubation mixtures of patient + pool normal plasma, and control at 2–8°C for 10 minutes and then measure the factor VIII. In […]

Bleeding Disorders

Still More on Xarelto and D-dimer

Here is further follow-up on our April 13 discussion entitled Xarelto and D-dimer (click or tap). In summary, a patient who was on Xarelto had markedly elevated D-dimer results reported by the laboratory where the patient was being treated, but normal D-dimer results when tested at two other laboratories using alternate technologies. George has since […]

Fibrinolysis

Platelet Clumps on Blood Film

Susan Lemire asks, “Hi, what are most people doing when platelet clumps are found on the blood smear, but the platelet count is within normal range?” Hi, Susan, my hunch is that since we don’t review blood films when the CBC is within acceptable parameters, we probably miss some platelet clumping. CBC profiling instruments do […]

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Platelet Function Testing

Aug 31 2016

george

Clotted Knee Fluid Cell Counts

From Susan Lemire: We received a solidly clotted knee fluid, with minimal non clotted blood. How do others handle these as far as reporting cell count and differential? From George: I’m not certain this approach would resolve your situation, but we treat synovial fluid with hyaluronidase to liquify the clot-forming hyaluronic acid before counting. I […]

Specimen Management

Fibrinogen Storage Stability

From Susan Lemire, can you confirm that the specimen stability for measuring fibrinogen is 24 hours? Thanks. Hi, Susan, the attached Scientific Reports article (a Nature publication) gives specimen stability for several coagulation factors and assay results. The study seems conclusive, as the authors used a sufficient sample of 72 specimens and referenced several additional […]

Specimen Management

Nijmegen Bethesda Assay

From Dr. Mirta Arias, Dear George, which is the procedure for determining the cut-off of Bethesda method and Nijmegen? Is there any Excel spreadsheet to perform it? Do you use only normal or normal and patients? Thanks, Mirta Hello, Dr. Arias, and thank you for your question. For a comprehensive answer, I turned to Amanda […]

Bleeding Disorders

Rivaroxaban Causes False LAC Positive

George reviewed this question posted to the American Society for Clinical Laboratory Science Consumer Web Forum: “After DVT/PE helped by TPA/heparin and now on Xarelto 4 weeks, my first blood draw shows factor VIII 228%, DRVVT screen 126 sec, confirmation 61 sec, normalized ratio 1.96, but hex phase phospholipid normal range and antiphospholipid normal range. […]

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Anticoagulant Therapy

Aug 15 2016

george

More on Reversing Plavix with Platelet Concentrate

Here are some follow-up comments to Dr. Larry Brace’s August 11, 2016 post about monitoring Plavix reversal with platelet concentrate. From Robert Gosselin, SSCLS, UC Davis: The thromboelastograph is not sensitive to platelet dysfunction. We could consider using their Platelet Mapping (PLTMAP) method, but there is no reference or therapeutic range provided, and the only […]

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Antiplatelet Therapy

All Posts

Specimens with Hematocrit >55%

How Many QC Repetitions?

Chilling The NBA Reaction Mixture

Still More on Xarelto and D-dimer

Platelet Clumps on Blood Film

Clotted Knee Fluid Cell Counts

Fibrinogen Storage Stability

Nijmegen Bethesda Assay

Rivaroxaban Causes False LAC Positive

More on Reversing Plavix with Platelet Concentrate

George Fritsma MS MLS

Cheat Sheets from George

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