Red Blood Cell Transfusion in the Emergency Department

Brit Long, MD; Alex Koyfman, MD


J Emerg Med. 2016;51(2):120-130. 

In This Article

Future Directions

The central nervous system is dependent on a consistent metabolic supply of nutrients, including oxygen, because the brain and spinal cord have little anaerobic reserve and are not able to compensate for decreased oxygen delivery in the setting of anemia.[89] Studies in patients with traumatic brain injuries and subarachnoid hemorrhages have suggested using a transfusion threshold of Hgb 8 to 9 g/dL, but more information is needed to develop true recommendations for transfusion.[90,91] A subgroup analysis of the TRICC trial analyzed patients with moderate and severe head injury, with transfusion thresholds of 7 g/dL and 10 g/dL. Similar to previous findings and suggestions, no difference in mortality, multiple organ dysfunction, or duration of hospital stay were found. However, this was a retrospective subgroup analysis.[92] A 2016 meta-analysis evaluated RBC transfusion in patients with traumatic brain injury and found no difference in mortality, with the transfusion threshold varying from Hgb 6 g/dL to 10 g/dL.[93]

Defining transfusion thresholds for acute myocardial ischemia is also necessary, because the current studies to date have enrolled low sample sizes, used different thresholds, evaluated different outcomes, and have significant bias and heterogeneity.[66,81–84] In reality, a definitive transfusion threshold for trauma is unlikely, because the majority of trauma patients are not managed based solely on laboratory markers.

Physicians should consider these transfusion thresholds and weigh the risks and benefits of transfusion. However, rather than relying on a laboratory level, the physician must evaluate the situation and patient. If the patient is hemodynamically stable and asymptomatic, Hgb 7 g/dL is safe and is associated with a lower risk of reaction and infection. If the patient is hemodynamically unstable and anemic, transfusion may assist the provider in stabilizing the patient.