title: Interruption of agitation of platelet concentrates: effects on in vitro parameters.
abstract: OBJECTIVE
  When platelet concentrates (PCs) are shipped from one centre to another, they may remain unagitated for a considerable period of time. It was therefore our aim to study the effects of interruption of agitation on the in vitro parameters of PCs stored in platelet additive solutions.
  
  
  METHODS
  In this multicentre study, PCs were prepared either by apheresis or from pooled buffy coats, paired to minimize donor-dependent differences, and aliquoted into 3 units with a 'low concentration' (approximately 1 x 10(9) platelets/ml; groups A, B and C) and 3 units with a 'high concentration' (approximately 2 x 10(9) platelets/ml; groups D, E and F). The final composition of the storage medium was 30% plasma and 70% additive solution in all PCs. Either PASIIIM or Composol was used as the additive solution. Agitation was interrupted for 2 days (between days 3 and 5, groups A and D), or for 4 days (between days 1 and 5, groups B and E), and continuous agitation served as the reference (groups C and F). A number of in vitro parameters were used for testing on days 1, 5 and 7.
  
  
  RESULTS
  On day 7, reference units C and F in PASIIIM had significantly higher pH values than the study units in PASIIIM, but all retained a pH of > 6.5 at 37 degrees C. Hypotonic shock response (HSR) results were significantly lower in the high concentration/4-day interruption group (E) than in the other groups. The low-concentration groups in PASIIIM, with agitation interrupted for either 2 days (group A) or 4 days (group B), did not have HSR values significantly different from the respective references. Study groups A, B, D and E in Composol, a solution lacking phosphate, had a pH of approximately 6.5 on day 7, which was significantly lower than that of the references and of the corresponding units in PASIIIM. The pH values were > 7.0 in reference groups C and F in Composol, not significantly different from those in PASIIIM. HSR values were also significantly lower in the Composol study groups. On the other hand, the reference Composol groups showed results similar to units in PASIIIM.
  
  
  CONCLUSIONS
  PCs in PASIIIM additive solution with a platelet concentration of approximately 1 x 10(9)/ml can sustain 4 days without agitation. Phosphate may be of importance in maintaining good in vitro characteristics during interruption of agitation.
authors.affiliation: Sanquin Blood Bank North-west Region, 1066 CX Amsterdam, the Netherlands. p.vandermeer@sanquin.nl
authors.forename: P F
authors.initials: PF
authors.lastname: van der Meer
authors.forename: H
authors.initials: H
authors.lastname: Gulliksson
authors.forename: J P
authors.initials: JP
authors.lastname: Aubuchon
authors.forename: C
authors.initials: C
authors.lastname: Prowse
authors.forename: E
authors.initials: E
authors.lastname: Richter
authors.forename: J
authors.initials: J
authors.lastname: de Wildt-Eggen
mesh_terms: D001792:Blood Platelets / Q000166:cytology; D001793:Blood Preservation / Q000592:standards*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009997:Osmotic Pressure; D010976:Platelet Count; D017713:Platelet Transfusion / Q000592:standards*; D012996:Solutions
chemical_list: D012996:Solutions