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

Abstract

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 2,599 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 to 1.14; p = 0.70). Similarly, no differences were observed in overall mortality (RR, 0.98; 95% CI, 0.85 to 1.12; p = 0.75), hospital mortality (RR, 1.02; 95% CI, 0.79 to 1.31; p = 0.89), or intensive care unit (ICU) mortality (RR, 0.74; 95% CI, 0.28 to 1.91; p = 0.53). Although transfusion reaction was non-significantly more frequent with liberal transfusion (RR, 1.13; 95% CI, 0.35 to 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).

Keywords: acute brain injury; anemia; liberal; restrictive; transfusion.