title: Hemolysis of red blood cells after cell washing with different automated technologies: clinical implications in a neonatal cardiac surgery population.
abstract: BACKGROUND
  In subsets of pediatric cardiac surgery patients, red blood cells (RBCs) are often washed to reduce extracellular potassium (K) to avoid hyperkalemia, but mechanical manipulation and time delay in issuing washed products may increase hemolysis and K. This study's purpose was to evaluate the quality of washed RBCs with regard to hemolysis and extracellular K using different cell washers as a function of postprocessing time.
  
  
  METHODS
  Fresh (<4 days old) RBCs were washed on COBE 2991 blood cell processors (Model 1 and Model 2) or the Fresenius Continuous AutoTransfusion System (CATS), and K and hemolysis index (HI) were analyzed. Academic pediatric hospitals were surveyed to ascertain practice trends regarding indications for washing, washing device, and expiration time for washed RBCs.
  
  
  RESULTS
  K concentration at 24 hours for units washed with the COBE devices met or exceeded prewash values. At 12 hours, there was a significant difference (p < 0.001) in K concentration between all devices, with the CATS maintaining the lowest K concentration. HI increased immediately after wash on all devices and showed a significant difference between the COBE devices and CATS at times of more than 6 hours (p < 0.01). At storage times beyond 4 hours, hemoglobin exceeded 100 mg/dL on the COBE Model 1. Survey of pediatric hospitals indicated that COBE devices are commonly used, and storage time after washing was 12 hours or more in blood banks queried.
  
  
  CONCLUSIONS
  Hemolysis levels vary among different cell washers. Decreasing the expiration time of units after washing may be warranted.
authors.affiliation: Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
authors.forename: Mandy Flannery
authors.initials: MF
authors.lastname: O'Leary
authors.forename: Penny
authors.initials: P
authors.lastname: Szklarski
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Klein
authors.forename: Pampee Paul
authors.initials: PP
authors.lastname: Young
mesh_terms: D001793:Blood Preservation / Q000295:instrumentation* / Q000379:methods; D006348:Cardiac Surgical Procedures; D017707:Erythrocyte Transfusion / Q000295:instrumentation* / Q000379:methods; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D006947:Hyperkalemia / Q000517:prevention & control*; D007231:Infant, Newborn; D011188:Potassium / Q000378:metabolism; D012996:Solutions; D013997:Time Factors
chemical_list: D012996:Solutions; D011188:Potassium