Evaluation of di-potassium and tri-potassium EDTA evacuated tubes for routine haematological testing

The influence of blood collection devices on laboratory tests is often overlooked. We have discussed here how blood collection materials and devices can alter haematological test results, with an emphasis on blood collection tube (BCT) additives. We have compared K2 & K3-EDTA vacuum tubes of same manufacturer IMPROVACUTER ^® for CBC analysis.

Blood was collected in both tubes simultaneously. Samples were analysed immediately after collection (<15 minutes) and after 4 hours by MEK-6318J/K Haematology Analyzer. Paired student's t-test was applied for statistical analysis. Significant differences among results and biases were compared with current quality specifications.

Significant differences were found in Neutrophyls (GR) and mean platelets volume (MPV) when compared. K2-EDTA vs K3-EDTA(1st time) after< 15 minutes of sample collection, for Monocytes counts (MO), MCV, MPV, and RDW when comparing K2-EDTA (first time) vs K2-EDTA(second time, after 4 hours); and for Monocytes counts (MO), MCV, MPV, PCT, and RDW when comparing K3-EDTA(1st time) vs K3-EDTA(2nd time) in order to check the stability and reproducibility of vacutainers.

This study assesses the use of K2& K3-EDTA vacuum tubes whether or not they represent a bias in haematological testing (CBC). The use of K2-EDTA and K3-EDTA vacuum tubes represent a clinically relevant source of variation for MCV, MPV, RDW, and PCT.