Bouboulis 1994.

Methods	Study was conducted between January 1993 and May 1993. Consecutive participants underwent elective or urgent coronary artery bypass surgery. All procedures were performed by the same cardiac surgeon. The method of randomisation and allocation concealment was not described.
Participants	75 consecutive participants undergoing coronary artery bypass graft surgery were randomised into one of two groups: Autotransfusion group: N = 42. Mean (SD) age = 60 (7) Control group: N = 33. Mean (SD) age = 59 (8) There was a between‐group baseline imbalance in cross‐clamp time (minutes).
Interventions	Autotransfusion group: autotransfusion group received autotransfusion of shed mediastinal blood using the cardiotomy reservoir, after the completion of the coronary artery bypass grafting (CABG). As soon as the chest was closed, the mediastinal tubes were attached to the inlet port of the cardiotomy reservoir, which allows the chest tube drainage to pass through a 20 micron filter. The filtered blood was collected in the bottom of the cardiotomy reservoir, ready for reinfusion. The vacuum port was attached to wall suction apparatus and negative pressure was instituted at 20 cm H2O. The chest drains were milked every 30 minutes. The collected blood was reinfused using a standard infusion pump. The hourly volume of mediastinal drainage was measured and the infusion pump adjusted to deliver this amount of blood over the next hour. Reinfusion was continued until the drainage was less than or equal to 50 mL per hour for two consecutive hours. Control group: control group received standard chest drainage. It is unclear whether blood remaining in the CPB at the end of the procedure was discarded or re‐transfused.
Outcomes	Outcomes reported: amount of blood collected by the cell saver, amount of blood re‐transfused from the cell saver, amount of allogeneic blood transfused, number of participants transfused allogeneic blood, complications, wound infection, re‐operation for bleeding, hospital length of stay, fever, mortality
Notes	Transfusion protocol: allogeneic packed cells were transfused intraoperatively or postoperatively when the haematocrit fell below 30%. Prospective registration status: the study was published prior to 2010. Ethical approval: approval by an institutional review board or ethics committee is not described. Language: the study is reported in English. Reason for awaiting classification status: the study contains a mixed population of participants undergoing elective and urgent surgery. No subgrouping has been performed for these indications.