Red Blood Cell Transfusion Guided by Near Infrared Spectroscopy in Neurocritically Ill Patients with Moderate or...

In neurocritically ill patients (NCPs), the use of hemoglobin level as the sole indicator for red blood cell transfusion (RBCT) can result in under- or over-transfusion. This randomized controlled trial was conducted to ascertain whether a transcranial oxygen saturation (rSO₂) threshold, as measured by near-infrared spectroscopy, reduces RBCT requirements in anemic NCPs (closed traumatic brain injury, subarachnoid, or intracerebral hemorrhage), compared with a hemoglobin threshold alone. Patients with hemoglobin 70-100 g/L received RBCTs to attain an rSO₂ > 60% (rSO₂ arm) or to maintain hemoglobin between 85 and 100 g/L (hemoglobin arm). A total of 102 NCPs (51 in each group) were included in the intention-to-treat analysis, and 97 were included in the per-protocol analysis (51 and 46, respectively). Compared with those from the hemoglobin arm, patients in rSO₂ arm received fewer RBC units (1.0 ± 0.1 vs. 1.5 ± 1.4 units/patient; p < 0.05) and showed lower hemoglobin levels while in protocol. There were no differences between the study arms regarding the percentage of transfused patents (59% vs. 71%; relative risk 0.83 [95% CI 0.62-1.11]), stay on neurocritical care unit (21 vs. 20 days), unfavorable Glasgow Outcome Scale scores on hospital discharge (57% vs. 71%), in-hospital mortality (6% vs. 10%), or 1 year mortality (24% vs. 24%). Among NCPs with hemoglobin concentrations of 70-85 g/L, withholding transfusion until rSO₂ is <60% may result in reduced RBCs requirements compared with routinely transfusing to attain a hemoglobin level >85 g/L. Further studies are required to confirm this finding and its possible impact on clinically significant outcomes.