title: Impact of incorrect filling of citrate blood sampling tubes on thromboelastometry.
abstract: BACKGROUND
  ROTEM(®) test results can be affected by the citrate to blood ratio in the tested sample. Overfilling or underfilling specimen tubes can change this ratio.
  
  
  OBJECTIVE
  The aim of this study was to determine the impact of under- and overfilling citrate test tubes on ROTEM(®) EXTEM measurements.
  
  
  RESULTS
  Overall repeated measures ANOVA demonstrated significant differences of CT (p = 0.004), CFT (p = 0.005), A5 (p = 0.001), A10 (p <0.001), and MCF (p < 0.001). Pairwise comparison revealed that underfilling significantly altered the results of those parameters reflecting functional clot firmness (A5, A10, and MCF), while overfilling led to a prolongation of the CT results only. No differences were observed for alpha angle and maximum lysis.
  
  
  CONCLUSIONS
  Both underfilling and overfilling specimen tubes have significant influence on the results of the ROTEM(®) EXTEM test, although the small observed bias is likely of limited clinical relevance. However, it seems prudent to limit the maximum allowed difference in filling to less than ± 10%. All ROTEM(®) operators should be aware of this pre-analytical variable.
authors.affiliation: a Department of Anesthesia , Zurich University Children's Hospital , Zurich , Switzerland.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Haas
authors.affiliation: a Department of Anesthesia , Zurich University Children's Hospital , Zurich , Switzerland.
authors.forename: Nelly
authors.initials: N
authors.lastname: Spielmann
authors.affiliation: b Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Cushing
mesh_terms: D016477:Artifacts; D001780:Blood Coagulation Tests; D001800:Blood Specimen Collection; D006801:Humans; D011446:Prospective Studies; D013916:Thrombelastography
keywords: Blood coagulation; pediatric anesthesia; point-of-care testing; thromboelastometry