title: Visual assessment of hemolysis in red blood cell units and segments can be deceptive.
abstract: BACKGROUND
  Blood components that appear hemolyzed are discarded. However, visual inspection is subjective and criteria for excessive hemolysis are poorly defined.
  
  
  METHODS
  Packed RBCs (10 CPDA-1, 10 Adsol) were collected. Half of each unit was leukoreduced. Plasma Hb was measured and compared in segments and units by three methods: 1) a HemoCue Plasma/Low Hb Photometer system; 2) a tetramethyl-benzidine (TMB) chemical method, and 3) a free Hb visual comparator.
  
  
  RESULTS
  Visual assessment tended to overestimate hemolysis. Chemical methods were comparable (r(2)= 0.894; HemoCue = 0.043 +[0.770]x TMB; n = 400; range, 0.01-0.5 g/dL), although the mean plasma Hb (g/dL) for the HemoCue method was higher than that of the TMB method (0.12 vs. 0.10 g/dL, respectively; p < 0.001). No units would have been discarded based on a hemolysis level of at least 0.6 g/dL (approx. 1%) if measured by a chemical method. However, 50 percent of CPDA-1 and 10 percent of Adsol units would have been discarded if only visual criteria were used. Leukoreduction did not increase plasma Hb levels. Discrepancies in plasma Hb levels were noted between units and their corresponding segments.
  
  
  CONCLUSIONS
  Visual assessment of hemolysis can result in unnecessary wastage of blood components. HemoCue offers an alternative, objective method to assess plasma Hb in the setting of blood collection and processing facilities for routine quality control and process validation, and may aid in the development of objective criteria for excessive hemolysis in blood components.
authors.affiliation: BloodSource and the University of California Davis Medical Center, Sacramento, California, USA. kim.janatapour@ucdmc.ucdavis.edu
authors.forename: K A
authors.initials: KA
authors.lastname: Janatpour
authors.forename: T G
authors.initials: TG
authors.lastname: Paglieroni
authors.forename: V L
authors.initials: VL
authors.lastname: Crocker
authors.forename: D J
authors.initials: DJ
authors.lastname: DuBois
authors.forename: P V
authors.initials: PV
authors.lastname: Holland
mesh_terms: D000925:Anticoagulants / Q000494:pharmacology; D001793:Blood Preservation; D017707:Erythrocyte Transfusion; D006454:Hemoglobins / Q000032:analysis*; D006461:Hemolysis; D006801:Humans
chemical_list: D000925:Anticoagulants; D006454:Hemoglobins