Search

Context: Technologic advances affecting analyzers used in clinical laboratories have changed the methods used to obtain many laboratory measurements, and many novel parameters are now available. The effects of specimen transport through a pneumatic tube system on laboratory results obtained with such modern instruments are unclear., Objective: To determine the effects of sample transport through a pneumatic tube system on routine and novel hematology and coagulation parameters obtained on state-of-the-art analyzers., Design: Paired blood samples from 33 healthy volunteers were either hand delivered to the clinical laboratory or transported through a pneumatic tube system., Results: No statistically significant differences were observed for routine complete blood cell count and white cell differential parameters or markers of platelet activation, such as the mean platelet component, or of red cell fragmentation. When 2 donors who reported aspirin intake were excluded from the analysis, there was a statistically, but not clinically, significant impact of transport through the pneumatic tube system on the mean platelet component. There were no statistically significant differences for prothrombin time, activated partial thromboplastin time, waveform slopes for prothrombin time or activated partial thromboplastin time, fibrinogen, or fibrin monomers., Conclusions: Although further study regarding the mean platelet component may be required, transport through a pneumatic tube system has no clinically significant effect on hematology and coagulation results obtained with certain modern instruments in blood samples from healthy volunteers.

Context: Blood collection tubes made from plastic are beginning to replace glass tubes. Coagulation test results can be influenced easily by preanalytic factors, including exposure to surfaces that activate the clotting cascade., Objective: To compare the effects of the blood collection tube material on 22 coagulation assays performed in clinical laboratories., Design: Paired blood samples from 28 healthy volunteers were drawn into BD Vacutainer Glass Citrate Tubes and BD Vacutainer Plus Plastic Citrate Tubes, and the results of coagulation assays were determined in parallel., Results: No statistically significant differences were observed between glass and plastic for 14 assays: prothrombin time (and international normalized ratio); activated partial thromboplastin time; activated protein C resistance; antithrombin activity; factors II, V, VIII, and IX; alpha2-antiplasmin; plasminogen activity; von Willebrand factor antigen; ristocetin cofactor; thrombin time; and reptilase time. Statistically significant differences were found for fibrinogen; chromogenic protein C activity; protein S activity; PTT-LA lupus anticoagulant-sensitive activated partial thromboplastin time; and factors VII, X, XI, and XII. Mean differences ranged from 0.4% to 5.5% and were unlikely to be of clinical significance., Conclusions: The results of this study suggest that plastic tubes can be used in place of glass tubes for a wide variety of coagulation assays.

The ADVIA 120/2120 Hematology System provides a number of novel parameters of platelet activation. Although the effects of anticoagulant in the blood-collection tube, short-term storage, and ambient temperature on these parameters have been documented in the literature, the effects of long-term storage and the material of the blood-draw tube have not been investigated. We therefore compared platelet activation parameter values obtained with the ADVIA 120 for 50 paired blood samples collected into BD Medical Systems' Vacutainer K(3)EDTA glass tubes and Vacutainer K(2)EDTA Plus plastic tubes and analyzed within 4 hours and after 24 hours following venipuncture. We found a statistically significant but clinically irrelevant decrease (less than 1%) in mean platelet component (MPC) concentration in plastic compared with glass for blood samples analyzed within 4 hours of draw. Reanalysis of the samples after 24 hours showed a clinically and statistically significant increase in mean platelet volume and significant decreases in MPC, platelet component distribution width, and mean platelet mass. These storage-induced changes were of equal magnitude for both tube types. We conclude that the use of plastic versus glass blood-draw tubes should have no clinically significant effect on the parameters of platelet activation on the ADVIA 120/2120 system and that the changes in platelet activation parameters continue to be present at 24 hours.

Blood-drawing tubes made from plastic containing K2EDTA as an anticoagulant are gaining widespread use in clinical hematology. We compared complete blood count parameters, reticulocyte counts, white blood cell differentials, and flagging rates obtained with Becton Dickinson Vacutainer K3EDTA glass tubes and Vacutainer K2EDTA Plus plastic tubes and found only slight discrepancies in the results obtained with the two tube types. Although some parameter values obtained with K3EDTA glass tubes were significantly lower than those obtained with K2EDTA plastic tubes, many of these differences could be explained by the known effects of the liquid K3EDTA anticoagulant. Flagging rates on an automated cell counter were identical for the two tube types. We conclude that the differences between results obtained with K3EDTA glass tubes versus K2EDTA plastic tubes are minimal and unlikely to be of any clinical significance.