The timing of tourniquet release and ‘retransfusion’ drains in total knee arthroplasty: A stratified randomised pilot investigation

The timing of tourniquet release is a potential confounding factor in the use of retransfusion drains in total knee arthroplasty. A pilot randomised trial was performed using retransfusion drains to determine whether releasing the tourniquet after wound closure reduced the overall blood loss and allogenic transfusion rate. Forty eight patients undergoing total knee arthroplasty were randomly allocated to receive either a retransfusion drain or no drain. Within each group the tourniquet was released before or after wound closure at the discretion of the surgeon. The peri-operative fall in haemoglobin, allogenic blood transfusion rate and complication rate were measured. There was an overall transfusion rate of 16%. There was no difference in the peri-operative fall in haemoglobin or the allogenic transfusion rates between the No Drain and Retransfusion Drain groups for patients undergoing total knee arthroplasty. Furthermore, the timing of the tourniquet release did not alter these findings. The results of this study suggest that the timing of the tourniquet release does not impact upon the ability of retransfusion drains to reduce the peri-operative fall in haemoglobin or the requirement for allogenic blood transfusion in total knee arthroplasty.