CHIlled Platelet Study "CHIPS"

Inclusion Criteria: * Viable neonates ≥ 3 kg at time of enrollment (as defined in Section 4.1) OR age greater than 28 days and less than 85 years of age at time of consent; AND * Planned complex cardiac surgery with planned use of cardiopulmonary bypass, with an expectation of bleeding requiring platelet transfusion. Exclusion Criteria: * Expected order for washed or volume reduced platelets * Patient with known anti-platelet antibodies * Platelet transfusion refractoriness due to anti-HLA antibodies * Known or suspected pregnancy * Previously randomized in this study * Conscious objection or unwillingness to receive blood products * Known IgA deficiency * Known congenital platelet disorder * Known congenital bleeding disorder * Planned post-operative extracorporeal membrane oxygenation (ECMO), ventricular assist device (VAD), and/or continuous renal replacement therapy (CRRT)/ hemodialysis * Patients intended to receive whole blood either intra-operative or post-operative for bleeding * Platelet transfusion (of any type) within 24 hours prior to the date of surgery * Pre-operative thrombocytopenia, defined as platelet count \<75x10(9)/L, based on the most recent labs completed within 72 hours prior to the date of surgery.