BACKGROUND:Blood transfusions are common in patients with acute brain injury, but the optimal hemoglobin threshold for transfusion remains unclear. This study aims to evaluate the effects of restrictive and liberal transfusion strategies on neurological outcomes in critically ill patients with acute brain injury.
METHODS:We searched PubMed, Embase, and Cochrane databases for randomized controlled trials (RCTs) comparing liberal versus restrictive transfusion strategies in patients with acute brain injury. The analyzed outcomes included (1) all-cause mortality; (2) red blood cell units per patient; (3) acute respiratory distress syndrome (ARDS); (4) infectious complications; (5) thromboembolic events, and (6) length of stay (LOS). Risk ratios (RRs) and 95 % confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed with I2 statistics. R version 4.4.1 was used for statistical analyses.
RESULTS:A total of 6 RCTs, comprising 2598 patients, were included in the analysis. Of these, 1307 (50,3 %) were assigned to the restrictive group. No significant difference was observed in unfavorable neurological outcome (RR 1.09, 95 % CI: 0.99-1.19) or all-cause mortality between restrictive and liberal transfusion thresholds (RR 1.021, 95 % CI: 0.890-1.172). Safety outcomes, including infectious complications (RR 0.974, 95 % CI: 0.868-1.092) and thromboembolic events (RR 0.802, 95 % CI: 0.392-1.642), were also comparable. Secondary outcomes showed no significant differences in ICU length of stay (MD -0,025, 95 % CI: [-1186]-1.136), hospital length of stay (MD 0.020, 95 % CI: [-1.826]-1.867), or the incidence of ARDS (RR 0.714, 95 % CI: 0.293-1.741). Notably, the restrictive strategy significantly reduced the number of red blood cell transfusions (MD -2.202, 95 % CI: [-2.998]-[-1.406]).
CONCLUSIONS:Restrictive transfusion may be resource-efficient, but current evidence does not confirm superiority over liberal strategies. Further studies are needed to clarify neurologic outcomes.