Liberal transfusion strategy does not improve post-traumatic brain injury neurologic outcomes

1. In this randomized controlled trial, among traumatic brain injury (TBI) patients with anemia, a liberal red-cell transfusion strategy resulted in no significant difference in neurological outcomes at six months compared with a restrictive transfusion strategy.

2. A liberal transfusion strategy was associated with improvement in several measures of functional independence and quality of life six months post-TBI. 

Evidence Rating Level: 1 (Excellent)

Study Rundown: Most critically ill patients with TBI develop anemia, which is thought to decrease oxygen delivery to an already vulnerable brain and further contribute to poor neurological outcomes among survivors. In recent years, standard practice for the treatment of anemia has favored a restrictive transfusion strategy, with transfusions given at lower hemoglobin levels, due to previous studies showing no mortality benefit associated with the maintenance of high hemoglobin levels. However, these studies did not focus on patients with TBI, for whom long-term neurologic function is a more important outcome than mortality. The present trial compared the effects of a liberal red-cell transfusion strategy with those of a restrictive strategy on the likelihood of unfavorable neurological outcomes, mortality, and scores on various measures of functional independence and quality of life six months post-TBI. Compared to a restrictive strategy, a liberal strategy resulted in a similar risk of unfavorable neurologic outcomes and mortality but was associated with better scores on some measures of motor function and quality of life. The study was limited by participants’ baseline risk of the unfavorable outcome being higher than expected, likely because patients with anemia also tend to have more severe TBI, making detecting minor treatment effects challenging. Additionally, the treatment groups were imbalanced at baseline, with the liberal-strategy group containing more patients with characteristics suggestive of a better prognosis at baseline, potentially confounding results. Nevertheless, these findings provide novel insights into the effects of a liberal transfusion strategy in critically ill patients with TBI and anemia.

Click to read the study in NEJM

In-Depth [randomized controlled trial]: This international randomized-controlled trial compared the effects of a liberal red-cell transfusion strategy with a restrictive strategy on the likelihood of unfavorable neurological outcomes, mortality, functional independence, and quality of life in patients with moderate to severe TBI and anemia. Patients 18 years of age or older with a Glasgow Coma Scale score of 3-12 and a hemoglobin level of ≤10 g/dL were included. The transfusion thresholds were hemoglobin ≤10 g/dL for the liberal-strategy group and ≤7 g/dL for the restrictive-strategy group. The primary outcome was an unfavorable neurologic outcome six months post-TBI, assessed using the Glasgow Outcome Scale-Extended (GOS-E). An unfavorable outcome was defined using a sliding dichotomy; patients were categorized as being at worst, intermediate, or best risk and considered unfavorable if their GOS-E score six months post-TBI was ≤ 3, 4, or 5, respectively. Secondary outcomes included mortality and scores on the Functional Independence Measure (FIM), Euro-Qol visual analog scale, EuroQol five-dimension, five-level (EQ-5D-5L) utility index, Quality of Life after Brain Injury (Qolibri) scale, and nine-item Patient Health Questionnaire (PHQ-9). Of 6,188 patients assessed for eligibility, 369 were assigned randomly to the liberal-strategy group and 367 to the restrictive-strategy group. A total of 68.4% of patients in the liberal-strategy group had an unfavorable outcome compared with 73.5% in the restrictive-strategy group (adjusted absolute difference, 5.4%; 95% Confidence Interval [CI], -2.9 to 13.7). Mortality at six months post-TBI was 26.8% in the liberal-strategy group compared to 26.3% in the restrictive-strategy group (hazard ratio for death, 1.01; 95% CI, 0.76 to 1.35). In summary, a liberal transfusion strategy did not produce a significant difference in risk of unfavorable neurological functional outcomes or mortality compared with a restrictive transfusion strategy. Still, it was associated with improvement in several functional independence measures and quality of life.

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