Optimal Brain Oxygenation in Neurologic Intensive Care Unit : The NeurO2 Study

The NeurO2 study is a multicenter prospective study nested within two large-scale pragmatic randomized open blinded endpoint (PROBE) trials in neurocritically ill patients, the HEMOTION and the SAHaRa trials. These two trials are designed to compare a restrictive and a liberal transfusion strategies in critically ill patients with traumatic brain injury or subarachnoid hemorrhage. The NeurO2 will report on prospectively gathered regional cerebral oxygenation data (rSO2) from enrolled patients randomized to either the liberal or restrictive RBC transfusion strategy of their parent trials. The primary outcome will be 6-month neurologic function based on the GOSe. The established infrastructure of the trials will be used, including part of the data collection instruments and the outcome assessment team.

The NeurO2 study will achieve three separate but interconnected primary objectives: i) Evaluate if the cerebral hypoxemic burden as measured by NIRS during NICU stay, is associated with functional neurologic outcome (Glasgow Outcome Scale extended - GOSe) at 6 months, ii) Determine if the cerebral hypoxemic burden is impacted by red blood cell transfusion, iii) Determine if the level of response in cerebral hypoxemic burden after RBC transfusion is associated with the 6-month functional neurologic outcome (GOSe)

The secondary objectives are to evaluate whether the cerebral hypoxemic burden measured by NIRS is associated with other clinically relevant outcomes including ICU, hospital and 6-month mortality and hospital, ICU length of stay and quality of life.