Methods	Randomised controlled trial of autotransfusion devices in patients undergoing knee-joint replacement surgery. Method of randomisation and allocation concealment was not described. [French article]
Participants	30 patients undergoing total knee arthroplasty were randomised to one of three groups: Group 1 (Autotransfusion group - Ortho-evac system): n=10; mean (sd) age = 68 (10) years Group 2 (Autotranfusion group - Solcotrans system): n=10; mean (sd) age = 70 (10) years Group 3 (Control group): n=10; mean (sd) age = 68 (15) years
Interventions	Group 1: Autotransfusion group (Ortho-evac system - not containing an anticoagulant) had their autotransfusion system connected to the deep suction drains in the operating room, after skin closure and before tourniquet removal. The salvaged blood was reinfused in the subsequent six hours via a 40 micron filter. The volume of collected blood was measured and allogeneic blood was added as required, to maintain a haematocrit of 30%. The Ortho-evac system had a 1000ml capacity. Group 2: Autotransfusion group (Solcotrans system - not containing an anticoagulant) had their autotransfusion system connected to the deep suction drains in the operating room, after skin closure and before tourniquet removal. The salvaged blood was reinfused in the subsequent six hours via a 40 micron filter. The volume of collected blood was measured and allogeneic blood was added as required, to maintain a haematocrit of 30%. The Solcotrans system had a 500ml capacity. Group 3: Control group did not receive autotransfusion.
Outcomes	Outcomes reported: amount of blood collected by the cell saver, number of patients transfused allogeneic blood, composition of drainage blood
Notes	Transfusion threshold: allogeneic blood was transfused to maintain a haematocrit of 30%
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was unclear.
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was unclear.
Blinding (performance bias and detection bias) All outcomes	High risk