Due to slow recruitment the study was terminated

Aim of the study is to investigate the impact of two different fractions of inspired oxygen (FiO2) on outcome in patients with severe traumatic brain injury (TBI).

The high oxygen group is treated during mechanical ventilation with either a fraction of inspired oxygen of 0.7 (high oxygen group) or a fraction of inspired oxygen 0.4 (control group). The intervention continues until withdrawal of mechanical ventilation, ICU discharge or until 14 days from ICU randomisation.

Primary outcome is worse than expected outcome in the corresponding treatment arms based on outcome meas-ured by the probability of bad outcome using the CRASH® risk calculator (prognostic model for predicting outcome after traumatic brain injury).

Secondary outcome is occurence of lung injury during mechanical ventilation.

Inclusion Criteria:

• Patients with isolated non-penetrating traumatic brain injury
• Multiple trauma patient with brain injury and traumas outside abdomen, thorax or pelvis not affecting oxygenation
• Glasgow coma scale eight or less (inclusive)
• Expected need for intubation and for mechanical ventilation more than 24 hours.
• Are recruited <18 hours after admittance to ICU and
• Time from TBI is less than 36 hours
• Informed consent from patients representative

Exclusion Criteria:

• Age <18 or >65 years,
• Anticipated brain death in 12 hours (donor treatment) or otherwise moribund patient expected to die in 24 hours
• Expected need for mechanical ventilation less than 24 hours
• Insufficient oxygenation assessed by a clinician or multiple trauma patients with brain injury and severe abdominal, thoracic or pelvic injury possibly affecting oxygenation.
• No consent
• Insufficient oxygenation with the treatment modality of the lower oxygenation group (Pa02 less than 13 kPa or SpO2 95% with Fi02 40%, PEEP 10 or less) or oxygenation failure probable during ICU care (severe aspiration, multiple trauma patients with brain injury and severe abdominal, thoracic or pelvic injury possibly affecting oxygenation)
• Penetrating TBI
• No consent
• Suspected pregnancy (perform urinary or serological pregnancy test if suspected)