Does the number of plasma separator tube inversions alter clinical chemistry and immunoassay test results on a Roche Cobas 8000 clinical chemistry platform?
Author(s): Bowen RAR, Esguerra V, Walker M
Publication: Clin Chim Acta, 2021, Vol. 515, Page 37-41
PubMed ID: 33388305 PubMed Review Paper? No
Purpose of Paper
This paper compared levels of 39 clinical chemistry analytes and the incidence of hemolysis, icterus, and lipemia in plasma isolated from blood collected in lithium heparin plasma separator tubes that were inverted 0, 4, or 8 times.
Conclusion of Paper
Levels of all 39 clinical chemistry analytes evaluated and the incidence of hemolysis (based on visual evidence), icterus, and lipemia were comparable in plasma from tubes that were inverted 0 or 4 times and the reference tube inverted 8 times. Further, none of the analytes had bias that was clinically relevant. A non-significantly higher number of aspiration errors occurred in specimens inverted 0 or 4 times relative to specimens inverted 8 times (7.5% and 2.5%, respectively, compared to 0%). The authors attribute the higher rate of aspiration error to improper mixing leading to fibrin strand formation.
Studies
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Study Purpose
This study compared levels of 39 clinical chemistry analytes and the incidence of hemolysis, icterus, and lipemia in plasma isolated from blood collected in lithium heparin plasma separator tubes that were inverted 0, 4, or 8 times. Blood was collected using a 21-gauge butterfly needle from 40 healthy volunteers (30 females and 10 males) into lithium heparin plasma separator tubes containing polymer gel. Matched tubes from each patient were inverted 0, 4, or 8 (reference) times before being placed vertically in a rack, transported to the laboratory, stored in the rack upright for 10 min followed by horizontally on the bench for 5 min. After storage, blood was centrifuged at 1300 x g for 10 min. Levels of 39 analytes were analyzed using a Roche Cobas 8000 system within 2 h of venipuncture. Using the Bonferroni method to correct for multiple comparisons, significance was set to P < 0.001. Percent bias was calculated using the tube that was inverted 8 times as a reference. The bias was considered clinically relevant if the percent bias exceeded the biological variation. Analytes included: albumin, amylase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, calcium, carbon dioxide, chloride, cortisol, c-peptide, C-reactive protein, creatinine, creatine kinase, direct bilirubin, ferritin, folate, free triiodothyronine, free thyroxine, gamma glutamyl transferase, glucose, high density lipoprotein-cholesterol, insulin, iron, lactate dehydrogenase, lipase, magnesium, phosphate, potassium, sodium, total bilirubin, total cholesterol, total protein, triglycerides, total triiodothyronine, total thyroxine, thyroid stimulating hormone, uric acid, and vitamin B12.
Summary of Findings:
There were no differences in the rate of hemolysis (based on visual evidence), icterus, or lipemia between tubes inverted 0 or 4 times compared to the reference tube that was inverted 8 times. Levels of all 39 analytes were not significantly different between tubes inverted 0 or 4 times compared to the reference tube that was inverted 8 times; none of the analytes evaluated had a clinically relevant bias. A non-significantly higher number of aspiration errors occurred in specimens inverted 0 or 4 times relative to specimens inverted 8 times (7.5% and 2.5%, respectively, compared to 0%). The authors attribute the higher rate of aspiration error to improper mixing leading to fibrin strand formation.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Carbohydrate Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Gas Clinical chemistry/auto analyzer Glycoprotein Clinical chemistry/auto analyzer Morphology Macroscopic observation Peptide Clinical chemistry/auto analyzer Protein Clinical chemistry/auto analyzer Small molecule Clinical chemistry/auto analyzer Steroid Clinical chemistry/auto analyzer Lipid Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Biospecimen mixing Not inverted
Inverted 4 times
Inverted 8 times