Over the past 25 years, >45 randomized clinical trials have shown that a restrictive transfusion strategy is best for most patients, except those with myocardial infarctions. Patients with acute brain injuries represent another unique subgroup who may benefit from more liberal transfusion thresholds, as cerebrovascular autoregulation limits the brain’s ability to compensate for reduced cardiac output, making it particularly vulnerable to hypoxia. However, few studies have specifically examined transfusion thresholds in neurocritically ill patients, and clinical practices vary widely. To elucidate the optimal transfusion thresholds for patients with traumatic brain injuries—aneurysmal subarachnoid hemorrhage or intracerebral hemorrhage—researchers randomized 850 patients (mean age, 51 years; 46% women; median hemoglobin [Hb], 8.5 g/dL) in 22 countries one-to-one to either a liberal transfusion threshold (<9 g/dL Hb) or restrictive threshold (<7 g/dL Hb) over 28 days. During the study, 90% of the patients in the liberal arm were transfused compared to 48% in the restrictive arm. Six months after randomization, 63% of patients in the liberal arm had an unfavorable neurological outcome (Glasgow Outcome Scale 1-5 or death) compared to 73% patients in the restrictive arm (adjusted relative risk, 0.86 [95% C.I., 0.79 to 0.94]; P=0.002). Furthermore, the incidence of having a cerebral ischemic event was lower in patients in the liberal arm (8.8%) compared to patients in the restrictive arm (13.5%), but mortality rates were similar in both arms. Based on this large, randomized trial, liberal transfusion thresholds may be considered for patients with acute brain injury, though further research is needed to confirm these results.
References:
- Turgeon AF, Lauzier F. Shifting Balance of the Risk-Benefit of Restrictive Transfusion Strategies in Neurocritically Ill Patients—Is Less Still More? Published online October 09, 2024
- Taccone FS, Rynkowski Bittencourt C, Møller K, et al. Restrictive vs Liberal Transfusion Strategy in Patients With Acute Brain Injury: The TRAIN Randomized Clinical Trial. Published online October 09, 2024. doi:10.1001/jama.2024.20424
