Cardiac Surgery Transfusion Strategy
The seminal Transfusion Requirements in Critical Care (TRICC) trial , which was published in 1999, compared clinical outcomes in intensive care patients randomized to a restrictive versus a liberal transfusion strategy (NEJM 1999;340:409-17). Patients in the restrictive cohort were transfused when their hemoglobin fell below 7 g/dL and their hemoglobin was maintained between 7–9 g/dL, while patients in the liberal transfusion group were transfused when their hemoglobin concentration fell below 10 g/dL and their hemoglobin was maintained between 10–12 g/dL. The TRICC trial demonstrated that a more restrictive transfusion strategy was safe in the ICU patient population and that the liberal use of transfusions increased the risk of death.
Since that time, many more randomized controlled trials involving surgical and intensive care unit patient populations in both adult and pediatric patient populations have demonstrated the non-inferiority of a restrictive transfusion strategy. However, previous randomized controlled trials have not focused on cardiac surgery patients.
A recently published paper compared liberal versus restrictive transfusion strategies in cardiac surgical patients (NEJM 2015;372:997-1008). Patients were randomized to restrictive (<7.5 g/dL) versus liberal (<9 g/dL) transfusion strategies.
Length of stay and overall cost were not statistically significantly different between the groups. However, the restrictive group appeared to have an increased risk of all-cause mortality (4.2%) at 90 days compared to 2.6% in the liberal group. This study suggests that a liberal red blood cell transfusion strategy might be beneficial for patients undergoing cardiac surgery.
