Methods	Generation of allocation sequences was made by a table of 52 random numbers with prospective assignment of patients. Concealment of treatment allocation was not described. Investigators recruiting patients were unaware of the treatment group to which patients would be assigned. Eight patients were withdrawn from the study
Participants	52 repeat open-heart surgery patients were randomised to one of two groups: Platelet-rich plasmapheresis: n = 25; M/F = not reported; mean (+/−SD) age = 64 (11) years. Control group: n = 19; M/F = not reported; mean (+/−SD) age = 77 (15) years
Interventions	Platelet-rich plasmapheresis (PRP) harvesting 15 ml/kg was performed after the establishment of appropriate invasive monitoring and intravascular access using Haemonetics Plasma Saver®. Control group were managed without PRP. NB: Patients in both groups received intra- and post-operative cell salvage
Outcomes	Number of patients transfused allogeneic blood (n). Units of allogeneic blood transfused. Blood loss (mls). Haematological levels. Coagulation levels. Hypotension during procedure (n). Re-operation for bleeding (n).
Notes	Quality assessment score (Schulz criteria): 2/7 Transfusion protocol used.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	Random number table was used to randomise patients
Allocation concealment?	Unclear	B - Unclear
Blinding? All outcomes	Yes	Although investigators recruiting patients were unaware of the treatment group to which patients would be assigned the control group received standard treatment with no PRP treatment. Study was assessed as being single blinded