Davies 1987.

Methods	Fifty patients having aortic surgery for either abdominal aortic aneurysm or aorto‐iliac occlusive disease were selected for study. Method of randomisation and allocation concealment was not described.
Participants	50 patients undergoing aortic surgery were randomly allocated to one of two groups: Group 1 (Autotransfusion group): n=25; M/F=21/4; mean (sd) age = 68 (8.0) years Group 2 (No intraoperative salvage group): n=25; M/F=22/3; mean (sd) age = 70 (8.0) years
Interventions	Group 1: Autotransfusion group (Sorenson autotransfusion system) had their blood loss from the surgical site suctioned into the Sorenson receptacle device and then retransfused at the time of surgery. Additional blood loss which was not able to be collected was replaced according to haematocrit levels, 3.5% polygeline being given if the haematocrit was above 30% and allogeneic blood if the haematocrit was below 30%. The collected blood was anticoagulated with an acid citrate dextrose solution and administered via a burette at a rate of 70ml for every 430ml of autologous blood collected. The scavenged blood was collected in a 1900ml sterile disposable Sorenson receptal ATS trauma liner contained within the rigid reusable receptal canister. When approximately 1 litre of autologous blood had been scavenged the liner was removed and this blood then administered to the patients after being filtered through a Pall 40um filter. Group 2: intraoperative blood loss was replaced with either 3.5% polygeline or allogeneic blood according to the measured Hct. If the Hct was above 30% then polygeline was used; if the Hct was below 30% then allogeneic blood was administered.
Outcomes	Outcomes reported: amount of blood re‐transfused from the cell saver, amount of allogeneic blood transfused, number of patients transfused allogeneic blood, mortality, re‐operation for bleeding, haemodialysis, blood loss, coagulopathy, Hb levels, organisms cultured from autologous vs allogeneic blood.
Notes	Transfusion threshold: patients received allogeneic RBC transfusion if the haematocrit level fell below 30%.
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 unclear.
Blinding (performance bias and detection bias) All outcomes	High risk