Ekback 1995.

Study characteristics
Methods	Design: RCT, parallel three‐arm, single‐centre study Setting: university teaching hospital, Örebro, Sweden Recruitment: recruitment and study dates not reported Maximum follow‐up: 7 days postoperatively
Participants	45 participants undergoing total hip arthroplasty were randomly allocated to one of three groups: Group 1 (Control/no cell salvage group): n = 15 Group 2 (Cell salvage/intervention group): n = 15 Group 3 (Autologous pre‐donation plus cell salvage group): n = 15 Demographic data were not reported; however, the authors state that there were no differences between groups with regard to demographic data. Participants in Groups 2 and 3 had significantly higher blood volume than those in Group 1.
Interventions	Group 1 (Control group/no cell salvage): blood loss was replaced with heterologous erythrocyte concentrate (SAGM‐ERC) and 3% dextran 60 in a ratio of 1:1. If necessary, additional SAGM‐ERC was transfused to correct erythrocyte volume fraction (EVF) > 27%. Group 2 (Cell salvage/intervention group): blood loss was replaced with 3% dextran and by autotransfusion of washed and haemoconcentrated blood salvaged by intraoperative suction and from wound drains up to 4 hours postoperatively. Haemonetic Cell Saver 4, Althin model AT 1000, or Shiley/Dideco STAT were used. Blood was retrieved from the operation site by suction through a double lumen catheter and was then anticoagulated with heparin (30,000 IU heparin in 1000 mL of physiological saline). The blood was collected into a reservoir where a macrofilter removed debris. Thereafter, the blood was pumped into a spinning centrifuge bowl (125 mL of blood) and washed with 1500 mL of physiological saline. The erythrocytes were concentrated to an EVF of about 50% to 60% and pumped into an infusion bag. The effluent containing platelets, free haemoglobin, and anticoagulants was disposed. As in Group 1, additional SAGM‐ERC was transfused to correct erythrocyte volume fraction (EVF) > 27%. Group 3 (Autologous pre‐donation plus cell saver group): blood loss was replaced with 3% dextran and by autotransfusion of washed and haemoconcentrated blood salvaged by intraoperative suction and from wound drains up to 4 hours postoperatively, as per the technique described for Group 2. Pre‐donated autologous SAGM‐ERC was used instead of heterologous blood to maintain erythrocyte volume fraction (EVF) > 27%. In 2 to 3 sessions within 6 weeks prior to the operation, 2 to 3 units of SAGM‐ERC had been withdrawn. If necessary, heterologous SAGM‐ERC was used if transfusion of all pre‐donated autologous blood failed to maintain EVF > 27%.
Outcomes	Outcomes reported: amount of allogeneic blood transfused, amount of autologous blood transfused, number of participants transfused allogeneic blood, complications, adverse events
Notes	Transfusion protocol: participants were transfused allogeneic blood to maintain the erythrocyte volume fraction (EVF) > 27%. Prospective registration status: the study was published prior to 2010. Ethical approval: the study was approved by the local hospital ethics committee. Language of publication: English Study groups: for the purposes of our review, Group 2 was used as the cell salvage/intervention group, while Group 1 was used as the control/no cell salvage group. Trial funding: not reported Conflicts of interest: not reported
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 of participants and personnel (performance bias) Objective outcome: mortality	Low risk	No objective outcomes reported (mortality unlikely to be affected by blinding if reported in future publications)
Blinding of participants and personnel (performance bias) Subjective: transfusion protocol	Low risk	Transfusion protocol: "additional heterologous SAGM‐ERC was transfused to maintain EVF > 27%"
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	High risk	No info on blinding ‐ may impact clinical decision‐making related to blood loss
Blinding of outcome assessment (detection bias) Objective outcomes: mortality and transfusions	Low risk	No objective outcomes reported (mortality unlikely to be affected by blinding if reported in future publications)
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	No info on blinding ‐ may impact clinical decision‐making related to blood loss
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No info on participant flow; 15 per group (45 total) at baseline, but unclear whether all were analysed
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	High risk	Funding and conflicts not reported. Some baseline imbalance: "Due to the small group sizes in our study, well balanced groups could not be achieved; a lower preoperative calculated blood volume in group I (Table 1); a higher preoperative APTT (within normal values) in group 2 ( Table 2); a lower preoperative R 1 (within normal values) in group 2 (Fig. (3 patients had Rl < 15%/min) were found."