Objective:

This study aims to perform a comprehensive meta-analysis of functional neurologic outcomes in moderate to severe blunt TBI (msTBI) patients with higher versus lower hemoglobin (Hgb) transfusion thresholds in the acute setting.

Background:

msTBI disproportionately affects younger populations with high mortality and severe morbidity amongst survivors. Active intracranial pathology of msTBI concomitantly with hemodynamic shock and impaired cerebrovascular autoregulation can significantly reduce brain tissue perfusion and oxygenation leading to hypoxic injury. Recent randomized trials revealed that more liberal Hgb transfusion thresholds >9g/dL may improve 6-month neurologic functional outcomes measured by Glasgow Outcome Scale Extended (GOS-E).

Design/Methods:

Medline, Embase, and Cochrane databases were searched for primary peer-reviewed literature concerned with msTBI and Hgb transfusion thresholds in early hospitalization involving 50 or more subjects, from inception to October 2025. Risk of bias was assessed for all selected articles. With a random effects model, we estimated the pooled risk ratio of unfavorable outcome at 6 months (GOS-E ≤4) and 30-day mortality for Hgb transfusion goal >9g/dL versus >7g/dL.

Results:

After review of 484 papers, 8 met inclusion criteria that reported 6-month functional neurological outcome and 10 that reported 30-day mortality. Patients with more liberal transfusion thresholds (>9g/dL) had a statistically significant reduction in unfavorable outcomes at 6 months (RR=0.81; 95%-CI [0.69-0.95]; p=0.0085) compared to those with goals at >7g/dL. Higher transfusion thresholds showed no significant effect on 30-day mortality.

Conclusions:

Higher Hgb transfusion thresholds (>9g/dL) in early treatment of msTBI patients can improve functional outcomes at 6 months for patients who survive the initial hospitalization.