Is hemoglobin good for cerebral oxygenation and clinical outcome in acute brain injury?

Purpose of reviewThe purpose of this review is to highlight the role of hemoglobin in cerebral physiology and pathophysiology. We review the existing as well as recent evidence detailing the effects of red blood cell transfusion on cerebral oxygenation and clinical outcome.Recent findingsHemoglobin is a key component in oxygen delivery, and thus cerebral oxygenation. Higher hemoglobin levels and red blood cell transfusion are associated with higher cerebral oxygen delivery and decreased cerebral ischemic burden. Recent studies suggest that this may be associated with improved clinical outcomes. However, these results are limited to only a few, small studies and the results have not been consistent. Further studies are required.SummaryHemoglobin is important for cerebral oxygenation and strategies to minimize anemia should be undertaken. Although higher hemoglobin levels are associated with less cerebral ischemia and better clinical outcome, whether this remains true whenever red blood cell transfusion is used to achieve this result remains unclear.