Effect of a liberal versus restrictive transfusion strategy on mortality in patients with moderate to severe head injury.

OBJECTIVE: To compare a restrictive versus a liberal transfusion strategy in patients with moderate to severe closed head injury following multiple trauma in 13 Canadian intensive care units (ICUs).

METHODS: This is a subgroup analysis of a multicenter randomized controlled clinical trial involving sixty-seven critically ill patients from the Transfusion Requirements in the Critical Care trial who sustained a closed head injury. Patients had a hemoglobin concentration less than 9.0 g/dL within 72 hours of admission to the ICU. Patients were randomized to a restrictive allogeneic red blood cell transfusion strategy (hemoglobin 7.0 g/dL and maintained between 7.0 and 9.0 g/dL) or a liberal strategy (hemoglobin 10.0 g/dL and maintained between 10.0 and 12.0 g/dL).

RESULTS: Baseline characteristics in the restrictive ( n = 29) and the liberal ( n = 38) transfusion groups were comparable. Average hemoglobin concentrations and red blood cell units transfused per patient were significantly lower in the restrictive compared to the liberal group. The 30-day all-cause mortality rates in the restrictive group were 17% as compared to 13% in the liberal group (risk difference 4.1 with 95% confidence interval [CI], 13.4 to 21.5, p = 0.64). Presence of multiple organ dysfunction (12.1 +/- 6.4 versus 10.6 +/- 6.3, p = 0.35) and changes in multiple organ dysfunction from baseline scores adjusted for death (4.5 +/- 6.2 versus 3.4 +/- 6.2, p = 0.49) were similar between the restrictive and liberal transfusion groups, respectively. Median length of stay in ICU (10 days, interquartile range 5 to 21 days versus 8 days, interquartile range 5 to 11 days, p = 0.26) and hospital (27 days, interquartile range 14 to 39 days versus 30.5 days, interquartile range 17 to 47 days, p = 0.72) were similar between the restrictive and liberal transfusion groups.

CONCLUSIONS: We were unable to detect significant improvements in mortality with a liberal as compared to restrictive transfusion strategy in critically ill trauma victims with moderate to severe head injury.