Rate of blood loss over 48 hours following total knee replacement.

The purpose of this study was to determine the rate of blood loss after total knee arthroplasty and assess the efficacy of drains using autologous blood transfusion. A prospective study was undertaken of 100 consecutive patients undergoing routine total knee arthroplasty. The diagnosis was osteoarthritis in 85% of patients and rheumatoid arthritis in 12% of cases. The rate of blood loss was recorded hourly for the first 12 h, 4 hourly for the subsequent 12 h and 6 hourly for the following 24 h. Autologous blood was reinfused within 12 h of surgery according to the protocol. Eighty-four percent of the total blood drained, was collected in the first 12 h and 94% in the first 24 h. 69% of the total blood which was drained was reinfused. The mean preoperative haemoglobin was 13.18 gm/dl and 10.23 gm/dl on the 5th day. A mean volume of 70-80 ml of homologous blood was reinfused in addition to the autologous transfusion in 11 of the 100 cases. There were no cases of deep or superficial sepsis, nor any identifiable complications related to the autologous blood transfusion. This study suggests it is safe to remove the postoperative joint drain after the 12-h period.