title: Understanding the effects of gamma-irradiation on potassium levels in red cell concentrates stored in SAG-M for neonatal red cell transfusion.
abstract: OBJECTIVE
  Red cell transfusions, to paediatric patients, are often gamma-irradiated to prevent transfusion-associated graft-versus-host disease. This study measured changes in potassium and other in vitro parameters immediately following gamma-irradiation of paediatric and full-size red cell concentrates (RCCs).
  
  
  METHODS
  The effects of irradiation on potassium release in RCCs stored in SAG-M were investigated under three scenarios. In the first scenario, RCC < 5 days was split into paediatric packs, gamma-irradiated and tested for potassium and haemolysis at 0, 2, 4, 6, 24 and 48 h. In the second scenario, full-size RCCs < 5 days postcollection were gamma-irradiated and tested as for the paediatric packs. Thirdly, RCCs < 14 days postcollection were gamma-irradiated and assessed at 6 and 24 h and 7 and 14 days. Each group contained paired controls that were not gamma-irradiated.
  
  
  RESULTS
  In all situations, gamma-irradiation resulted in a twofold increase in potassium concentrations after 24 h of storage, compared to matched unirradiated controls. This difference was detectable as early as 2 h postirradiation. Few differences were observed between control and irradiated RCCs in other key parameters, including ATP, 2,3-DPG, haemoglobin, pH, glucose and lactate concentration.
  
  
  CONCLUSIONS
  Gamma-irradiation of RCCs significantly increased extracellular potassium. Irradiation of fresher RCCs results in lower potassium concentrations, which is less likely to lead to hyperkalaemia upon transfusion.
authors.affiliation: Research and Development, Australian Red Cross Blood Service, Sydney, NSW, Australia.
authors.forename: K M
authors.initials: KM
authors.lastname: Winter
authors.forename: L
authors.initials: L
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Kwok
authors.forename: S
authors.initials: S
authors.lastname: Reid
authors.forename: Z
authors.initials: Z
authors.lastname: Alarimi
authors.forename: J K L
authors.initials: JK
authors.lastname: Wong
authors.forename: P M
authors.initials: PM
authors.lastname: Dennington
authors.forename: D C
authors.initials: DC
authors.lastname: Marks
mesh_terms: D001793:Blood Preservation / Q000379:methods; D004912:Erythrocytes / Q000378:metabolism / Q000528:radiation effects*; D005720:Gamma Rays; D006461:Hemolysis; D006801:Humans; D011188:Potassium / Q000097:blood*
chemical_list: D011188:Potassium
keywords: gamma-irradiation; paediatric transfusion; potassium; red blood cells; transfusion-associated hyperkalaemia