Brand of dipotassium EDTA vacuum tube as a new source of pre-analytical variability in routine haematology testing.

This study assesses the use of different dry K2 (dipotassium) EDTA vacuum tubes and whether or not they might represent a bias in haematological testing. Blood was collected in three dipotassium EDTA vacuum tubes from different manufacturers: Venosafe, Vacuette and Vacutainer. Samples were analysed on an Advia 2120i analyser. Significant differences among results and biases were compared with current quality specifications. Significant differences were found for haematocrit (HCT), mean corpuscular volume (MCV), white blood cell count (WBC) and platelet distribution width (PDW) when comparing Venosafe vs. Vacuette; for MCV, WBC and PDW when comparing Venosafe vs. Vacutainer; and for HCT and MCV when comparing Vacuette vs. Vacutainer. Clinically significant variations were observed for HCT and PDW in Venosafe vs. Vacuette; PDW in Venosafe vs. Vacutainer; and HCT and MCV in Vacuette vs. Vacutainer. The use of dipotassium EDTA vacuum tubes from different manufacturers represent a clinically relevant source of variation for HCT, MCV and PDW.