A new study published in JAMA demonstrates that a liberal blood transfusion strategy, targeting a hemoglobin level of greater than 9 g/dL, significantly improves neurological outcomes in critically ill adults with acute brain injuries compared to a restrictive strategy targeting levels greater than 7 g/dL.
The international, multicenter TRAIN trial, led by Fabio Silvio Taccone and colleagues, enrolled 850 patients with acute brain injuries, including traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage, across 72 sites in 22 countries. The study compared the impact of liberal versus restrictive transfusion strategies on neurological outcomes.
Key Findings of the TRAIN Trial
The primary outcome, an unfavorable neurological outcome at 6 months defined as a Glasgow Outcome Scale Extended (GOS-E) score of 1 to 5, occurred in 62.6% of patients in the liberal transfusion group compared to 72.6% in the restrictive transfusion group. This represents a significant absolute risk reduction of 10% (adjusted relative risk, 0.86; 95% CI, 0.79-0.94; P=.002).
"Patients with acute brain injury and anemia randomized to a liberal transfusion strategy were less likely to have an unfavorable neurological outcome than those randomized to a restrictive strategy," the authors concluded.
Impact on Cerebral Ischemia
Interestingly, the liberal transfusion strategy was also associated with a lower incidence of cerebral ischemic events. In the liberal strategy group, 8.8% of patients experienced at least one cerebral ischemic event, compared to 13.5% in the restrictive strategy group (relative risk, 0.65; 95% CI, 0.44-0.97).
Consistency Across Subgroups
Subgroup analysis based on the type of brain injury (traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage) showed consistent findings, suggesting that the benefit of a liberal transfusion strategy extends across various types of acute brain injuries.
Limitations and Considerations
The study acknowledges the lack of blinding as a limitation but mitigated potential bias by blinding outcome assessors to treatment assignments. The authors also note that while the trial included a heterogeneous population, the consistent findings across subgroups strengthen the generalizability of the results.
Comparison with Previous Studies
The TRAIN trial's findings align with those of the HEMOTION trial, which also suggested a benefit of a liberal transfusion strategy in patients with traumatic brain injury. However, the trials differed in several aspects, including transfusion thresholds and patient populations.
Implications for Clinical Practice
The results of the TRAIN trial provide strong evidence supporting a liberal transfusion strategy for neurocritically ill patients with anemia. According to the authors, a liberal transfusion strategy is a simple intervention that can be easily and rapidly implemented worldwide, including in low- and middle-income countries.
"Based on the best available evidence, it is prudent to advocate a liberal transfusion strategy for these neurocritically ill patients," the authors stated.
