Delayed release of drain in total knee replacement reduces blood loss. A prospective randomised study.

Total knee arthroplasty is sometimes associated with major post-operative bleeding, often requiring transfusion. A prospective, randomised study was undertaken to assess the effect on post-operative bleeding of delaying release of the clamp on the suction drains. One hundred patients were allocated into two groups: Group A- immediate release of drain following release of tourniquet, and Group B- delayed release of the drain clamp by one hour. There was a statistically significant reduction (p = < 0.001) in postoperative bleeding between group A (1050 ml; 95%CI 728 - 1172 ml) compared to group B (732 ml; 95% CI 620- 845 ml). Average drop in corrected haemoglobin and postoperative transfusion requirement were also less in the delayed group. The results show that delaying release of the drains by one hour reduces postoperative blood loss and transfusion requirement following total knee arthroplasty.