Processing of diagnostic blood specimens: is it really necessary to mix primary blood tubes after collection with evacuated tube system?

Author(s): Lima-Oliveira G, Lippi G, Salvagno GL, Brocco G, Gaino S, Dima F, Volaski W, Rego FG, Picheth G, Guidi GC

Publication: Biopreserv Biobank, 2014, Vol. 12, Page 53-9

PubMed ID: 24620770 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of delaying or eliminating the mixing step during blood collection on clinical chemistry, hematology, and coagulation parameters. Specimens were collected from 300 outpatient volunteers in either sodium citrate, lithium heparin, or K2EDTA vacuum tubes. Hematological parameters were evaluated within 15 min of blood collection. Centrifugation protocols were different between the tube types, and the authors do not examine the effects of the different anticoagulants, but once plasma was separated, it was stored frozen at -70 degrees C until analysis. Significance was defined as p<0.017.

   Summary of Findings:

   Out of 52 analytes examined for mixing delay or elimination effects, the only statistically significant differences found were higher red blood cell counts and hematocrit in specimens inverted immediately compared to those rested 5 min before inversion, higher alanine aminotransferase and lower erythrocyte sedimentation rates in specimens inverted immediately compared to those not inverted, and lower red blood cell counts, hematocrit, and hemolysis index in specimens rested 5 min before inversion compared to those not inverted. Interestingly, sodium levels showed a clinically significant decrease (0.7%) when specimens were rested before inversion compared to those inverted immediately or those not inverted at all, but these differences were statistically insignificant. No other clinically relevant decreases were observed.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen
   • None (Fresh)

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Cell count/volume	Hematology/ auto analyzer
   Protein	Hematology/ auto analyzer
   Glycoprotein	Hematology/ auto analyzer
   Morphology	Hematology/ auto analyzer
   Carbohydrate	Clinical chemistry/auto analyzer
   Steroid	Clinical chemistry/auto analyzer
   Lipid	Clinical chemistry/auto analyzer
   Protein	Clinical chemistry/auto analyzer
   Small molecule	Clinical chemistry/auto analyzer
   Electrolyte/Metal	Clinical chemistry/auto analyzer
   Cell count/volume	Spectrophotometry

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Aliquots and Components	Biospecimen mixing	Inverted 5 times immediately after collection Inverted 5 times after a 5 min rest in upright position Not mixed

   View more