Reference Study design Sample size Hyperoxemia definition Condition Location Conclusion [33 ], Young et al. Retrospective cohort 2,643 - Ischaemic stroke ICU No association with mortality. [34 ], Rincon et al. Retrospective cohort 2,894 PaO2 40.0 kPa Ischaemic stroke, subarachnoid or intracerebral hemorrhage ICU Associated with higher in-hospital mortality, also when compared to hypoxemia. [35 ], Lång et al. Retrospective cohort 432 - Subarachnoidal hemorrhage ICU Unfavorable outcome associated with higher PaO2 , but higher PaO2 levels after multivariate analysis not associated with unfavorable outcome or mortality [36 ], Singhal et al. Randomized pilot study, partially blinded 16 O2 45 L/min, 8 hours Ischaemic stroke - Transient improvement of clinical deficits and MRI abnormalities after 24 hours [37 ], Padma et al. Randomized pilot study, partially blinded 40 O2 10 L/min, 12 hours Ischaemic stroke - No improvement in functional or neurological outcome after 3 months [38 ], Nortje et al. Prospective cohort 11 FiO2 35–50% TBI - Increases brain tissue oxygenation. [39 ], Tisdall et al. Prospective cohort 8 FiO2 100% TBI Neurological ICU Increases cerebral aerobic metabolism. [40 ], Vilalta et al. Prospective cohort 30 FiO2 100% TBI ICU Improves brain redox state in patients with initially elevated brain lactate levels [41 ], Diringer et al. Prospective cohort 5 FiO2 100% TBI Neurosurgical ICU No improvement on brain metabolism. [42 ], Puccio et al. Prospective cohort 11 FiO2 100% TBI Neurotrauma ICU Brief periods do not produce oxidative stress and/or change antioxidant reserves in cerebrospinal fluid. [43 ], Davis et al. Retrospective cohort 3,420 PaO2 64.9 kPa TBI - Independently associated with increased mortality and decrease in good outcomes. [44 ], Rincon et al. Retrospective cohort 1,212 PaO2 40.0 kPa TBI ICU Independently associated with higher in-hospital mortality. [45 ], Asher et al. Retrospective cohort 193 PaO2 64.8 kPa TBI - Decrease in survival [46 ], Raj et al. Retrospective cohort 1,116 PaO2 13.3 kPa TBI ICU No effect on 6 month mortality