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

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

The NeurO2 study is a multicenter observational study looking at NIRS monitoring in neurocrocritically ill patients during the acute phase of care following an acute brain injury. The study is nested within the HEMOTION Trial and the SAHaRA Trial

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.

Inclusion criteria:

• Enrolment in one of the parent trials (HEMOTION or SAHaRA trials)
• HEMOTION trial (acute moderate of severe blunt traumatic brain injury (Glasgow Coma Score18 [GCS] ≤ 12))
• SAHaRA trial (acute subarachnoid hemorrhage as confirmed by treating neurosurgeon or neuro-interventionist and supported by blood in subarachnoid space resulting from a ruptured aneurysm)
• Adult patients (age ≥18 years old)
• Patients suffering from anemia (Hb ≤100 g/L)

Exclusion criteria:

• Contraindications or known objections to blood transfusions
• Active bleeding with hemodynamic instability at the time of enrollment
• Decision to withdraw or withhold life-sustaining therapies made
• NIRS monitoring not reliable