Methods	All patients scheduled for non-emergency first-time coronary artery bypass graft surgery (CABG), valve surgery or combined CABG and valve procedures requiring cardiopulmonary bypass (CPB) were eligible for enrolment. Operations associated with a high risk of transfusion, such as transplantation and operations on the thoracic aorta were excluded
Participants	213 patients undergoing first-time CABG and/or cardiac valve surgery were randomised to one of two groups: Group 1 (Autotransfusion group): n=102; M//F=78//24; mean (sd) age = 68.6 (9. 6) years Group 2 (Control group): n=111; M//F=84//27; mean (sd) age = 67.4 (10.2) years
Interventions	Group 1: Autotransfusion group (C.A.T.S Fresenius Hemocare system) had their suctioned blood processed before and after CPB with the cell salvage apparatus. After weaning from CPB blood remaining in the CPB circuit was processed by the cell saver device. All recovered blood, with no minimum volume due to the design of the cell salvage device, was transfused to the patient. Post-operatively the cell saver was transferred with the patient to the ICU and connected to the chest tubes. All blood lost during the first 6 hours was processed and autotransfused. Cell salvage was disconnected after 6 hours. Group 2: Control group had all blood suctioned before and after CPB discarded. After CPB any remaining blood in the bypass machine tubing and reservoir was collected in the bag and transfused directly to the patient.
Outcomes	Outcomes reported: number of patients transfused allogeneic blood, amount of allogeneic blood transfused, number of patients transfused fresh frozen plasma, number of patients transfused platelets, blood loss, adverse events, re-operation for bleeding
Notes	Transfusion threshold: patients were transfused allogeneic blood when the haemoglobin level fell below 7.0g/dL during surgery, and fell below 8.0g/dL post-operatively
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Patients were allocated to intervention or control by simple randomisation generated by an independent statistician using a computer random number function, stratified by type of surgery
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was not described
Blinding (performance bias and detection bias) All outcomes	High risk