Case report

https://doi.org/10.11613/BM.2017.047

What´s floating on my plasma?

Janne Cadamuro ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
Helmut Wiedemann ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
Thomas K. Felder ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
Cornelia Mrazek ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
Ulrike Kipman ; UT SPSS Statistics, Hallein, Austria
Oberkofler Hannes ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria
Elisabeth Haschke-Becher ; Department of Laboratory Medicine, Paracelsus Medical University, Salzburg, Austria

Abstract

We report on a preanalytical issue we encountered during routine clinical chemistry analyses, potentially leading to deviated analysis results and believe that it might help other laboratories to overcome similar problems. In a heparin-gel tube we measured an implausible glucose value of 0.06 mmol/L. Re-measurement of the same sample resulted in a glucose value of 5.4 mmol/L. After excluding an analytical error, we inspected the sample closer and found a white material as well as fatty droplets floating on the surface of the plasma tube. Evaluation of these structures revealed that the white particulate matter (WPM) consisted of fibrinogen, platelets and leukocytes and the fatty droplets most probably originated from the separator gel. We concluded that these structures formed a temporary clot in the instruments pipetting needle thereby altering the sampling volume and subsequently the measured glucose value. The formation of WPM might be attributable to high speed centrifugation, high cholesterol levels, the gel formulation or a combination of several issues such as temperature, heparin concentration, pH and patient-specific factors. The gel droplets were most probably caused by an aberrant gel formulation in combination with an improper storage of the empty tubes on the wards prior to phlebotomy. After adding an additional instrument cleansing cycle and changing to another batch of heparin tubes the problems could be significantly reduced.

Keywords

case report; white particulate matter; lithium-heparin tubes; separator gel

Hrčak ID:

183396

URI

https://hrcak.srce.hr/183396

Publication date:

15.6.2017.

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