Liberal versus restrictive strategy of red blood cells transfusion in oncology surgery: a randomised controlled clinical trial

OBJECTIVES: The purpose of this study was to evaluate whether a restrictive strategy of red blood cell (RBC) transfusion was superior to a liberal one for reducing mortality or severe clinical complications among patients undergoing major abdominal cancer surgery. DESIGN: Phase III, randomised, unicentric, controlled, parallel-group, superiority trial. SETTING: Intensive care unit (ICU) of Instituto do Cancer do Estado de Sao Paulo, Faculdade de Medicina da Universidade de Sao Paulo, a tertiary oncology university hospital in Sao Paulo, Brazil PARTICIPANTS: All adult patients with cancer who were undergoing major abdominal surgery requiring postoperative care in the ICU were included. INTERVENTIONS: Patients were randomly allocated during intensive care unit stay to treatment with either a liberal RBC transfusion strategy (transfusion when haemoglobin concentration decreased below 9 g/dL) or a restrictive RBC transfusion strategy (transfusion when haemoglobin concentration decreased below 7 g/dL). MAIN OUTCOME MEASURES: The primary outcome was a composite endpoint of all cause mortality or severe complications (cardiovascular complications, acute respiratory distress syndrome, acute kidney injury requiring renal replacement therapy, septic shock and reoperation) at 30 days. RESULTS: A total of 198 patients were included in the final analysis; 101 randomised to the restrictive group and 97 to the liberal group. Haemoglobin concentrations were higher during the study period in the liberal group with a greater use of RBC transfusions. The primary composite endpoint occurred in 19.6% (95% confidence interval [CI] 12.9 to 28.6) of patients in the liberal strategy group and in 35.6% (95%CI 27.0 to 45.4) of patients in the restrictive strategy group (p=.012). Compared to the restrictive strategy, the liberal transfusion strategy resulted in an absolute risk reduction for the composite outcome of 16% (95%CI 3.8 to 28.1) and a number needed to treat of 6.2...