title: [Key Preparation Technique and Clinical Application of Frozen Platelets].
abstract: OBJECTIVE
  To explore the key technique for preparation of the frozen platelet and efficacy of its clinical application.
  
  
  METHODS
  The influences of the donators' peripheral platelet count, starting time of freeze, injection rate and evenness of the freeze-protective agent, storage mode, re-melting temperature and the capacity of water-bath etc. on the quality of the frozen platelets were analyzed retrospectively in 3 257 samples of frozen platelets before platelet pheresis. Then, the platelet counts were examined in 150 cases transfused with frozen platelets at the time-points of 1, 24, 48 and 72 hrs after transfusion, 90 cases suffered from the obstetrical bleeding were transfused with 200 parts of the re-melting frozen platelets, and then the peripheral blood platelet count, platelet increasing index(CCI), bleeding time and blood clot retraction rate etc. were observed for determining the clinical efficiency of the frozen platelets.
  
  
  RESULTS
  The floccule in the re-melting frozen platelets from the donators with (175-250)×10(9)/L platelets were decreased significantly(P<0.01). The quality of frozen platelets was influenced by the following factors, such as injection of DMSO at a too fast and heterogeneous rate, blood bags stored in a multilamminar space, and re-melting in a water-bath of small capacity etc. The routine storage for 0 and 3 days did not influence the quality of the frozen platelets. The recovery rate of one year-freezing platelets all was higher than 80%. The effects of the frozen platelets transfused into the patients with obstetrical bleeding displayed good haemostatic results, and the blood transfusion reaction did not occur. However, the frozen platelets immediately were exhausted and displayed their function, but the counting after 48 hrs could not display a good effect of raising platelet number.
  
  
  CONCLUSIONS
  The peripheral platelet count before platelet pheresis, the injection rate and evenness of the protective agent, the number of stratum for blood bags and the capacity of re-melting water-bath etc. all are the key factors influencing the quality of the frozen platelets. The frozen platelets prepared in this study shows a good efficacy of clinical application.
authors.affiliation: Dongying Central Blood Station, Dongying 257091,Shandong Province,China.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Ding
authors.affiliation: Dongying People's Hospital, Dongying 257091,Shandong Province,China.
authors.forename: Wei-Sheng
authors.initials: WS
authors.lastname: Qin
authors.affiliation: Dongying Central Blood Station, Dongying 257091,Shandong Province,China.
authors.forename: Lin-Yuan
authors.initials: LY
authors.lastname: Zhao
authors.affiliation: Dongying Central Blood Station, Dongying 257091,Shandong Province,China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Dongying Central Blood Station, Dongying 257091,Shandong Province,China.
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Bo
authors.affiliation: Dongying Central Blood Station, Dongying 257091,Shandong Province,China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Blood Transfusion, The General Hospital of Chinese PLA , Beijing 100853.E-mail:13280373125@126.com.
authors.forename: Jing-Han
authors.initials: JH
authors.lastname: Liu
mesh_terms: D001792:Blood Platelets; D001793:Blood Preservation; D001803:Blood Transfusion; D005615:Freezing; D006487:Hemostasis; D006801:Humans; D010976:Platelet Count; D017713:Platelet Transfusion; D010983:Plateletpheresis; D065227:Transfusion Reaction