The aim of this study was to demonstrate the benefits of a simple blood transfusion protocol in Primary Total Knee Replacement.

Patients undergoing TKR in the UK usually have either blood cross matched or have an auto transfusion of drained blood postoperatively. Audit of blood requirements of patients undergoing TKR showed that a large amount of blood was wasted. A CT ratio (Ratio of number of units of blood cross matched to number of units transfused) of 4.86 was obtained. Range recommended by the blood transfusion society is 2: 1 to 3: 1. A protocol was then made to Group and Save and Antibody Screen for all patients having a primary TKR, except patients with haemoglobin less than 12.5 gm/dl pre operatively and those patients with multiple red cell antibodies in their blood.

A further study involving 50 patients was carried out using the new protocol. Two units of blood was cross matched for each of 5 patients (3 with Hb < 12 gm/dl and 2 with red cell antibodies). Post operatively the 3 patients with Hb < 12 gm/dl required blood transfusion of 2 units each, reducing the CT ratio to 1.7: 1.

The benefits from above protocol are : a). Patient safety as risks of transfusion are avoided and b). Cost saving for trust on haematology technician time and on transfusion sets which cost around £70 each.