A pilot multicentre blinded randomised controlled clinical trial of frozen platelets vs. conventional liquid-stored platelets for the management of post-surgical bleeding

Cryopreserved platelets. Each cryopreserved platelet unit will be prepared by the Australian Red Cross Blood Service from a unit of standard apheresis platelets. Cryopresevation will occur within 24 hours of platelet collection. The method of cryopreservation will be based closely on that described by the Netherlands Sanquin Blood Bank (Lelkins et al., Transfus.Apher.Sci. 2006; 34: 289-98), using 27% Dimethyl sulphoxide (DMSO) as a cryoprotectant, with removal of most of the DMSO by centrifugation prior to freezing. Each unit will be reconstituted using approximately 280 ml fresh frozen plasma. Patients randomised to recieve this intervention will be given a maximim of three cryopreserved units intravenously, as determined necessary by their treating clinicians. The administration of the platelets will only occur in the Operating Theatre or during the patients stay in the Intensive Care Unit (ICU), which is usually 24-48 hours. Patients may receive only one bag of platelets, or up to three, over a period of hours as determined by the clinicians. Once the patient is discharged from the ICU, no further study platelets will b given. Conventional platelets will be given if determined to be necessary by the treating clinical team. At The Prince Charles Hospital, a substudy examining impedance aggregation and viscoelastic parameters at point of care immediately before and at set time points after transfusion of study platelets will be conducted. The intent of this study is two-fold: firstly, to examine whether cryopreserved platelets produce different results to conventional, liquid stored platelets using these relatively new techniques (i.e. “are the platelets different?”) and secondly to examine the relationship between these test results and clinical indices of platelet haemostatic efficacy that will be quantified as part of the main trial (i.e. “do these novel tests of platelet function reflect bleeding outcomes?”). Appendix 1 dated 19 APR 16 for The Prince Charles Hospital substudy of platelet function testing. All participants enrolled at Prince Charles Hospital under that CLIP inclusion/exclusion criteria and will also completee the sub-study.