Zhao 1996.

Methods	Prospective, randomised controlled trial was conducted to determine whether the autotransfusion of shed mediastinal blood after open heart surgery is safe and effective. Method of randomisation and allocation concealment were not described.
Participants	42 patients undergoing cardiac operations were randomised to one of two groups: Group 1 (Autotransfusion group): n=22; mean (sd) age = 49 (11.0) years Group 2 (Control group): n=20; mean (sd) age = 45 (12.0) years
Interventions	Group 1: Autotransfusion group patients received non‐washed shed mediastinal blood during the post‐operative period. Group 2: Control group received banked blood only. Autotransfusion was not performed.
Outcomes	Outcomes reported: amount of blood re‐transfused from the cell saver, amount of allogeneic blood transfused, blood loss, Hb levels.
Notes	Transfusion threshold: transfusion protocol was not reported. English abstract only.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was not described.
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