Murphy 2005.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: university teaching hospital, Bristol, Avon, UK Recruitment: 16‐month period. Specific recruitment and study dates are not reported. Maximum follow‐up: duration of hospital stay
Participants	61 participants undergoing cardiac surgery were randomly allocated to one of two groups: Autotransfusion group (Cell salvage/intervention group): N = 30. M:F 25:5. Mean (SD) age 62.3 (9.3) Control group: N = 31. M:F 23:8. Mean (SD) age 66.4 (7.6) The groups were balanced before surgery with regard to demographics and comorbidities, apart from a higher frequency of unstable angina symptoms in the auto‐transfusion group.
Interventions	Autotransfusion group: cell salvage group (Dideco Compact autotransfusion system) underwent intraoperative cell salvage with autotransfusion of washed salvaged red blood cells at the completion of the operative procedure. All blood lost, from skin incision to skin closure, was salvaged via a single‐lumen suction tube flushed with heparinised saline and connected to the closed rigid collection chamber of the Dideco Compact autotransfusion device at high‐pressure suction. Before autotransfusion, the heparinised salvaged intraoperative blood underwent a washing process, with re‐suspension of the red blood cells in saline, to an Hct of approximately 0.6. This red blood cell suspension was then transferred to a sterile collecting bag that was disconnected from the autotransfuser and administered via a standard blood giving set. Salvaged washed red blood cells were autotransfused at the time of skin closure. Control group: control group received standard care without autotransfusion.
Outcomes	Outcomes reported: number of participants transfused allogeneic blood, volume of blood collected by the cell saver, volume of blood re‐transfused from the cell saver, number of participants transfused fresh frozen plasma (FFP), number of participants transfused platelets, blood loss, mortality, adverse events
Notes	Transfusion protocol: the threshold for transfusion of allogeneic blood was a haemoglobin level < 8.0 g/dL or a haematocrit < 0.23. In participants with excessive blood loss and cardiovascular instability, blood was given at the discretion of anaesthetic or intensive care unit staff. Prospective registration status: the study was published prior to 2010. Ethical approval: the study received local ethics committee approval. Language of publication: English Trial funding: not reported Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Method used to generate allocation sequences was adequate: participants were assigned to 1 of 2 randomised groups, autotransfusion or control, in a 1:1 ratio by using block randomisation. Allocations were generated by a card system and concealed in sealed opaque envelopes.
Allocation concealment (selection bias)	Low risk	Method used to conceal treatment allocation was adequate: participants were assigned to 1 of 2 randomised groups, autotransfusion or control, in a 1:1 ratio by using block randomisation. Allocations were generated by a card system and concealed in sealed opaque envelopes.
Blinding of participants and personnel (performance bias) Objective outcome: mortality	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of participants and personnel (performance bias) Subjective: transfusion protocol	Low risk	Transfusion protocol in place: the threshold for transfusion of homologous blood was haemoglobin < 8 g/dL or haematocrit < 0.23.
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	High risk	No blinding, assignment preoperatively, may have impacted on some care
Blinding of outcome assessment (detection bias) Objective outcomes: mortality and transfusions	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	No blinding, may impact some outcomes, especially LOS
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants randomised are accounted for in the reported outcomes, appears to be ITT
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	Some baseline imbalance that may impact cardiovascular outcome measures (the 2 groups were balanced before surgery with respect to demographics and comorbidity, apart from a higher frequency of unstable angina symptoms in the autotransfusion group). No info on funding or conflicts