Under filled di potassium-ethylene di amine tetra acetic acid vacutainers and its effect on automated blood cell indices in healthy blood donors: Is there a need to re-investigate it as a rejection criterion?

Introduction: Standard guidelines assert that any vacutainer, which is 10% less under-filled should be rejected as it may affect the results. These guidelines refer to the studies using liquid K 3 -ethylene diamine tetra acetic acid (EDTA). Although the new guidelines recommend K 2 -EDTA instead of earlier K 3 -EDTA but has not clearly commented upon whether the same holds true for the new anticoagulant K 2 -EDTA. Materials and Methods: Blood samples from 100 healthy blood donors were included. We took 7-8 ml of blood and was then transferred to three 3 ml capacity vacutainers-up to 3 ml, 2.5 ml, 1 ml (marked a, b, c respectively) containing spray-dried K 2 -EDTA as anti-coagulant. Thus, b and c vacutainers were under-filled. Hematological parameters in all the samples were analyzed immediately using automatic analyzer (Cell Dyn). Statistical analysis was done with the help of SPSS v. 17.0 (Chicago, IL, USA) using one-way ANOVA. Results: The results showed that three groups were comparable with respects to hemoglobin, hematocrit, total leukocyte count, differential leukocyte counts, total platelets, mean corpuscular volume, mean hemoglobin concentration, mean cellular hemoglobin concentration along with red cell distribution width. Conclusion: Our study suggested that under-filling till 67% (1 ml in 3 ml standard capacity) of the recommended volume in a spray-dried K 2 -EDTA vacutainers did not affect hematological parameters in healthy people. In view of these results, there is need to further investigate the same in diseased. If further studies done on under filling of the pathological samples also give similar results as in our study then only the present guidelines related to under filling could be revised when K 2 -EDTA is used as an anticoagulant.