Transfusion strategies in neuroanaesthesia and neurocritical care.

Purpose of review: This review examines the evolving evidence regarding optimal transfusion strategies in neurosurgical populations, addressing the critical balance between maintaining cerebral oxygen delivery and avoiding transfusion-associated complications. The unique physiological vulnerability of the injured brain necessitates reevaluation of conventional transfusion thresholds derived from general critical care populations.

Recent findings: Recent multicenter randomized controlled trials have demonstrated heterogeneous effects of liberal vs. restrictive transfusion strategies across different neurological pathologies. In traumatic brain injury (TBI), the HEMOTION and TRAIN trials suggest potential benefits of liberal strategies (hemoglobin thresholds of 9-10 g/dl) for neurological recovery and reduction in cerebral ischemic events. Conversely, the Subarachnoid Hemorrhage Red Cell Transfusion Strategies and Outcome trial in aneurysmal subarachnoid hemorrhage found no significant difference between liberal (≤10 g/dl) and restrictive (≤8 g/dl) strategies regarding unfavorable neurological outcomes. Evidence for optimal hemoglobin thresholds in brain tumor surgery remains limited by the absence of large randomized trials.

Summary: The emerging evidence challenges the universal application of restrictive transfusion practices in neurocritical care, suggesting that optimal transfusion thresholds may be pathology-specific. While liberal strategies may benefit TBI patients, equivalent outcomes with restrictive approaches in subarachnoid hemorrhage indicate the need for nuanced, evidence-based protocols tailored to specific neurological conditions.