| Methods |
Concealment of treatment allocation was by use of sealed envelopes. Method of generating allocation sequences was not described. |
| Participants |
90 patients undergoing primary total knee arthroplasty were randomised to one of three groups:
Group 1 (No drain group): n=30, M/F=11/13, mean age (95% CI) = 70 (67‐74) years Group 2 (Autotransfusion group): n=30, M/F=4/20, mean age (95% CI) = 71 (69‐74) years Group 3 (Control group): n=30, M/F=9/16, mean age (95% CI) = 72 (69‐75) years
|
| Interventions |
Group 1: No drain was used. Group 2: Solcotrans autotransfusion system collected blood for 6 hours or until the unit was full. Acid citrate dextrose‐anticoagulant (ACD‐A) was not added to the collection unit. Continuous suction was applied at 20cm H2O. Drains were maintained for 24 hours post‐operatively. Group 3: A standard disposable closed suction drainage system (Redon) was used with two standard drains maintained for 24 hours post‐operatively. |
| Outcomes |
Outcomes reported: number of patients transfused allogeneic blood, blood loss, hospital length of stay, Hb and Hct levels. |
| Notes |
Transfusion threshold: allogeneic blood transfusion was given if the haemoglobin level was less than 9.0g/dL. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
High risk |
Randomisation was carried out with sealed envelopes, opened just before closure of the wound. Method used to generate allocation sequences was not described. |
| Allocation concealment (selection bias) |
High risk |
Sealed envelopes were used to conceal treatment allocation. |
| Blinding (performance bias and detection bias)
All outcomes |
High risk |
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