Red blood cell transfusion in patients with severe traumatic brain injury: a systematic review

The traumatic brain injury (TBI) remains one of the most prevalent and disabling conditions globally, representing a major public health burden. Anemia is common among neurocritical patients, and red blood cell (RBC) transfusions are frequently administered. Although restrictive transfusion strategies have shown outcomes comparable or superior to liberal strategies in various critical settings, in TBI patients, anemia may exacerbate secondary brain injuries due to cerebral hypoxia. Its objective is to identify red blood cell (RBC) transfusion thresholds and associated neurological outcomes in patients with severe traumatic brain injury (TBI). The investigation design is systematic review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions (version 2.0). The method is searching PubMed, Web of Science, and Scopus databases, retrieving 986 articles, along with 108 additional records from other sources. After removing 516 duplicates, 169 full-text articles were screened. A total of 22 studies met the inclusion criteria and were included in the final analysis. The main outcome measures are transfusion thresholds (restrictive vs. liberal) and associated neurological outcomes in severe TBI patients. The current literature supports restrictive transfusion protocols (Hb < 7 g/dL) over liberal thresholds (Hb < 10 g/dL) in patients with severe TBI. However, evidence is limited and heterogeneous, and individualized approaches are recommended. In conclusion, restrictive transfusion strategies may be as effective or superior in improving neurological outcomes in patients with severe TBI, but further high-quality studies are needed to guide clinical decision-making.