Labs want to minimize pre-analytical errors as much as possible—in order to improve the quality of blood test results, reduce the number of specimens requiring re-collection, reduce turnaround time, and improve patient management. Blood collection tubes (BCTs), which are typically thought of simply as inert specimen carriers, have been shown to contribute to pre-analytical errors. It’s not totally understood why this is the case, but the issue could have a greater influence on test results than many health professionals realize, explains Raffick Bowen, PhD, MHA, MT (CSMLS), DClChem, FCACB, DABCC, FACB, in the December issue of CLN.
Components of BCTs, including tube walls, rubber stoppers, lubricants, anticoagulants, separator gels, clot activators, and surfactants, can affect the quality of specimens and accuracy of laboratory tests. These components and additives have the potential to alter the composition of serum and plasma fractions by adding constituents to blood, adsorbing elements, interacting with protein and cellular components, or altering the stability of analytes in blood specimens.
Can anything be done to minimize the risk of errors? Other than increasing vigilance when inspecting laboratory test results and improving communication between the clinical laboratory and clinicians, laboratorians can’t do much to detect BCT problems readily without looking at population means (moving averages) of their assays. Following population means at regular timed intervals can alert the laboratory of potential problems with BCTs.
To evaluate interferences from collection device components in clinical tests, laboratorians should follow this process: (1) test the same analyte with an alternative assay; (2) incubate the sample with the different parts of the collection device to identify the source of potential interferences; (3) contact both the collection device and assay manufacturers; (4) if necessary, file a medical device alert with the Food and Drug Administration; and (5) if possible, switch to a new BCT manufacturer.
Also, well-planned validation protocols should be written and reviewed for scientific validity by qualified individuals for any new or substantially modified BCTs introduced to the laboratory.
Pick up the December issue of CLN for more advice for reducing pre-analytical errors.