Feasibility Trial to Compare Restrictive vs. Liberal Blood Transfusion

Study Questions:

Is a restrictive or liberal red blood cell (RBC) transfusion policy for acute upper gastrointestinal (GI) bleeding in routine clinical practice feasible and safe?


TRIGGER was a pragmatic, multicenter, open-label, cluster randomized feasibility trial of a restrictive versus liberal RBC transfusion policy in adults with acute GI bleeding in the United Kingdom. Patients were eligible if they presented with new acute upper GI bleeding (defined by hematemesis or melena); the only exclusion criterion was exsanguinating hemorrhage. Hospitals were randomized to either a restrictive (transfusion when hemoglobin concentration fell below 80 g/dl) or liberal (transfusion when hemoglobin concentration fell below 100 g/dl) RBC transfusion policy. Feasibility outcomes were recruitment rate, protocol adherence, hemoglobin concentration, RBC exposure, and selection bias. The main exploratory clinical outcomes were further bleeding and mortality at day 28.


Recruitment rate was significantly higher for the liberal than for the restrictive policy (62% vs. 55%; p = 0.04). Protocol adherence was 96% (standard deviation, 10) in the restrictive policy versus 83% (25) in the liberal policy (difference, 14%; 95% confidence interval, 7-21; p = 0.05). 247 (46%) of 533 patients allocated to the liberal policy were transfused compared with 133 (33%) of 403 patients allocated to the restrictive policy (difference, -12%; 95% confidence interval, -35 to 11; p = 0.23). There were no significant differences in clinical outcomes.


This cluster randomized feasibility trial demonstrated that this design was associated with rapid recruitment, high protocol adherence, and nonsignificant reduction in RBC transfusion in the restrictive policy. There was no significant difference in clinical outcomes.


Although upper GI bleeding is unfortunately not uncommon, the optimum threshold for transfusion has not been established. The authors of this study provide evidence for the feasibility of a phase 3 trial to investigate liberal versus restrictive transfusion policies. As the authors emphasize, ‘A key area of uncertainty in transfusion practice concerns safe transfusion thresholds in patients with ischemic heart disease.’

Clinical Topics: Prevention

Keywords: Erythrocyte Transfusion, Gastrointestinal Hemorrhage, Hematemesis, Hemoglobins, Hemorrhage, Melena, Myocardial Ischemia, Primary Prevention

< Back to Listings