title: Under-filled blood collection tubes containing K2EDTA as anticoagulant are acceptable for automated complete blood counts, white blood cell differential, and reticulocyte count.
abstract: Current laboratory standards from Clinical Laboratory Standards Institute (CLSI) and manufacturer's (Becton Dickinson) data indicate that under-filling K(2)EDTA blood collection tubes can result in erroneous hematology values. To accommodate under-filled tubes and reduce collection volumes while optimizing our automation, we explored the acceptable limit of under-filled tubes for hematology values. We collected 8.0 ml of blood from 30 normal adult volunteers. Each donation was aliquoted in the following volumes: 4.0, 2.0, 1.0, 0.5 ml x 2. These samples were analyzed within 1 h of blood collection on Sysmex XE-2100 (Sysmex America Inc., Mundelein, IL, USA) for complete blood count, reticulocyte, and white blood cell differentials. Results of the under-filled tubes were compared to those of the standard volume. The Deming regression analysis show excellent correlation for all parameters between each under-filled blood collection volume compared to a standard 4 ml volume. The Bland and Altman analysis shows good agreement between both 1.0 and 2.0 ml compared to a 4.0 ml volume. The 0.5 ml compared to a 4.0 ml volume, however, shows increased variation on many parameters. In addition all three collection volumes show negative bias compared to the standard volume for platelet count, but the difference is considered insignificant with a percent difference of 5.5%, 3.2%, and 1.5% for 0.5, 1.0, and 2.0 ml collection volume respectively. Finally for 0.5 ml collection volume we noticed a low level of false positive flagging rate for white blood cell. Acceptable complete blood count values of under-filled powdered K(2)EDTA tubes can be obtained with as little as 1.0 ml of blood.
authors.affiliation: Department of Laboratories, Seattle Children's Hospital, Seattle, WA 98105, USA. min.xu@seattlechildrens.org
authors.forename: M
authors.initials: M
authors.lastname: Xu
authors.forename: V A
authors.initials: VA
authors.lastname: Robbe
authors.forename: R M
authors.initials: RM
authors.lastname: Jack
authors.forename: J C
authors.initials: JC
authors.lastname: Rutledge
mesh_terms: D000328:Adult; D000925:Anticoagulants; D001772:Blood Cell Count / Q000592:standards*; D001800:Blood Specimen Collection / Q000295:instrumentation* / Q000592:standards; D004492:Edetic Acid; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000295:instrumentation / Q000592:standards*; D017701:Reticulocyte Count / Q000295:instrumentation / Q000592:standards*
chemical_list: D000925:Anticoagulants; D004492:Edetic Acid