PRBC Transfusions in Neurocritical Care

• Historically, neurocritical care textbooks have favored a more liberal PRBC transfusion strategy, as the brain is very sensitive to decreases in oxygen delivery.
• Despite these recommendations, limited studies have failed to show a mortality benefit to PRBC transfusion in critically ill patients with neurologic illness.
• Postulated reasons for the lack of morbidity or mortality benefit center around the injured brain's response to attempts to increase oxygen delivery through transfusion.
  • TBI: PET studies have shown an overall lower level of metabolic activity along with a lower oxygen extraction and loss of autoregulation
  • SAH: transfusion may increase the risk of vasospasm in SAH and worsen flow
• Although the evidence is not overwhelming, current recommendations from SCCM-Eastern Society for the Surgery of Trauma recommend a restrictive PRBC transfusion threshold (Hgb < 7 gm/dL) even in neurocritical care patients.

References

Netzer G, Hess JR, Shanholtz C. Use of blood products in the intensive care unit: Concepts and controversies. Contemporary Critical Care June 2010;8(1):1-12