Restrictive strategy, transfusion at haemoglobin below 7 g/dL
Control
Liberal strategy, transfusion at haemoglobin below 10 g/dL
Population
838 euvolaemic critically ill patients
Follow-up
30 days
Primary endpoint
30-day all-cause mortality
Result
30-day mortality was 18.7% with the restrictive strategy versus 23.3% with the liberal strategy (p=0.11). Rates were significantly lower with restriction among less acutely ill patients and those under 55.
Secondary endpoints
In-hospital mortality, organ dysfunction, cardiac events
A restrictive strategy of red-cell transfusion is at least as effective as and possibly superior to a liberal transfusion strategy in critically ill patients, with the possible exception of patients with acute myocardial infarction and unstable angina.
The trial authors, in the published abstract
How it has aged
The foundation of restrictive transfusion across all of medicine, and its exception clause — myocardial infarction and unstable angina — has kept researchers busy ever since (MINT, REALITY). Twenty-five years on, 7 g/dL remains the default nearly everywhere.
Publications
A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group
Hébert PC, Wells G, Blajchman MA, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. N Engl J Med 1999 Feb 11;340(6):409-17.
30-day mortality 18.7% restrictive versus 23.3% liberal
Benefit clearest in younger and less acutely ill patients
Authors flagged myocardial infarction as a possible exception