Investigating the Effect of Intravenous and Oral Tranexamic Acid on Blood Loss After Primary Hip and Knee Arthroplasty

Patients having a hip or knee replacement can lose almost a third of their blood during and after the operation. Many patients, especially those who are older will need a blood transfusion, suffer from anaemia, or have a slow recovery after the operation. Tranexamic acid is a medication used to treat or prevent excessive blood loss, but in joint replacements, is only used in patients who are likely to bleed a lot. This trial aims to find out how well tranexamic acid works to reduce blood loss after the operation in a large group of patients having a hip or knee replacement, including those at risk of blood clots. This study also aims to find out how safe tranexamic acid treatment is to use in different patients and the best way to give tranexamic acid (in tablet form or through a drip), as well as how much to give and how long it should be given after an operation. All adults awaiting non-emergency hip or knee replacement surgery will be considered. Patients who are suitable and agree to take part are randomly placed in one of two treatment groups: receiving tranexamic acid during the hip or knee operation through a drip, or receiving treatment during the hip or knee operation through a drip plus taking a tablet every 8 hours up to 24 hours after the operation. Initially, a no treatment group was included, however, one year after the trial started, the Data Monitoring and Ethics Committee who check safety, advised to stop allocation of patients to the no treatment group. For all patients, blood loss is recorded up to 48 hours after surgery. Blood samples are also taken in order to measure how well the heart and blood clotting systems are working. If the routine kidney function tests taken before the operation show less than normal function, a lower dose of tranexamic acid is used. It is expected that patients who receive the tranexamic acid will lose much less blood during and after their operation, and so be less likely to need a blood transfusion, have reduced