title: Just scratching the surface: varied coagulation effects of polymer containers on TEG variables.
abstract: OBJECTIVE
  Different types of polymer surfaces affect the activation of platelets and coagulation pathway containers depending on their surface qualities. Importantly, this could produce variability of coagulation results obtained with thrombelastographical analysis. We assessed the effects of blood storage on thrombelastograph, TEG, variables using polypropylene and polycarbonate containers.
  
  
  METHODS
  An in vitro experiment was performed, with eight volunteers in each limb. Fresh whole blood was stored in polypropylene or polycarbonate tubes prior to TEGanalysis, to assess the role of these plastics in the TEG results obtained.
  
  
  RESULTS
  The polycarbonate tubes displayed slower onset of coagulation and greater variability of data for all four basic TEG variables (r-time, k-time, alpha-angle and maximum amplitude, P < 0.05). Polycarbonate results fell outside manufacturer reference ranges.
  
  
  CONCLUSIONS
  It is likely that this is due to the altered surface properties and charge effects of the containers affecting proteins and platelets differently. Caution should be used in choosing which containers are used for storage of fresh blood prior to coagulation assessment, as variable results will follow where different types of plastic containers are employed.
authors.affiliation: Duke University Medical Center, Department of Anesthesiology, Durham, NC 27710, USA. tony.roche@duke.edu
authors.forename: A M
authors.initials: AM
authors.lastname: Roche
authors.forename: M F M
authors.initials: MF
authors.lastname: James
authors.forename: M P W
authors.initials: MP
authors.lastname: Grocott
authors.forename: M G
authors.initials: MG
authors.lastname: Mythen
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects*; D004349:Drug Packaging; D006801:Humans; D066298:In Vitro Techniques; D015539:Platelet Activation / Q000187:drug effects; D011076:Polycarboxylate Cement / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D011126:Polypropylenes / Q000737:chemistry / Q000494:pharmacology; D013048:Specimen Handling; D013499:Surface Properties; D013916:Thrombelastography
chemical_list: D011076:Polycarboxylate Cement; D011108:Polymers; D011126:Polypropylenes; C005506:polycarbonate