Liberal vs. restrictive transfusion strategy for acute brain injury: A meta-analysis with trial sequential analysis of randomized clinical trials

Background

Acute brain injury is a critical health challenge with substantial mortality and morbidity. While anemia is common in these patients and may worsen outcomes, the optimal red blood cell transfusion strategy remains controversial.

Objective

We conducted a meta-analysis with trial sequential analysis of randomized controlled trials (RCTs) comparing liberal versus restrictive transfusion strategies in patients with acute brain injury.

Methods

Pubmed, Embase, and the Cochrane Library databases were searched through December 15, 2024, for RCT comparing liberal (hemoglobin threshold 9−10 g/dL) versus restrictive (hemoglobin threshold 7−8 g/dL) transfusion strategies in adults with acute brain injury. The primary outcome was an unfavorable neurological outcome.

Results

Six RCTs involving 2599 patients were included. There was no significant difference in unfavorable neurological outcomes between liberal and restrictive strategies (risk ratio [RR], 0.97; 95% confidence interval [CI], 0.83–1.14; p = 0.70). Similarly, no differences were observed in overall mortality (RR, 0.98; 95% CI, 0.85–1.12; p = 0.75), hospital mortality (RR, 1.02; 95% CI, 0.79–1.31; p = 0.89), or intensive care unit (ICU) mortality (RR, 0.74; 95% CI, 0.28–1.91; p = 0.53). Although transfusion reaction was non-significantly more frequent with liberal transfusion (RR, 1.13; 95% CI, 0.35–3.58; p = 0.84).

Conclusions

In patients with acute brain injury, a restrictive transfusion strategy was not associated with worse neurological outcomes or higher mortality compared to a liberal strategy.

Implications for clinical practice

Maintaining hemoglobin levels above 7–8 g/dL may be effective for patients with acute brain injury, potentially reducing unnecessary transfusions and associated risks.

Meta-analysis registration

registered on PROSPERO under number CRD42025639745.