A multi-centre randomised controlled trial of Transfusion Indication Threshold Reduction on transfusion rates, morbidity and healthcare resource use following cardiac surgery (Titre 2)
Indications for blood transfusion after cardiac surgery are poorly defined. Unnecessary blood transfusions increase healthcare costs both directly, because blood is an increasingly scarce and expensive resource, and indirectly, due to complications associated with transfusion. Transfusion may cause complications by reducing patients’ ability to fight off infection and respond to the stress that surgery puts on the body, as well as (rarely) by transmitting viral infections present in donor blood. In the UK, cardiac surgery uses more than 6% of all donor blood (and about 10% of donor blood in the UHBristol, a tertiary cardiac surgery centre). Although the benefits of red cells for managing life-threatening bleeding are clear, the majority of decisions to transfuse after surgery are made on the basis of a patient’s haemoglobin (Hb) level (a measure of the ability of the blood to transport oxygen around the body). The level that causes a doctor to transfuse a patient varies widely and randomised trials in non-cardiac surgical fields have shown that lowering the level that ‘triggers’ transfusion reduces complications as well as the use of blood.
The research was carried out in a number of UK hospitals. Patients whose Hb level dropped below the level at which transfusion is conventionally given were assigned by chance to have decisions made: (a) more or less as they are now, or (b) only when the Hb level drops to a lower, ‘restrictive’ level. The primary outcome was the number of infectious (sepsis) and ischaemic (stroke, heart attack or kidney failure) complications that occurred during the first 3 months after surgery.
Dr Rachel Brierley recently hosted a webinar entitled ‘Methods to manage the randomisation and treatment of patients 24/7 in a large multi-centre RCT’ as part of the HTMR Trial Conduct Working Group Webinars 2016-2017.