one of the major advantages of bureaucratic institutionalized national healthcare systems is the ability to analyze treatment pdigms implemented across a wide population , providing a comprehensive overview of clinical care with the view to improve quality and outcome . in a retrospective interrogation of a prospectively collected database , raj and colleagues demonstrate that the presence of arterial hyperoxia within the first 24  hours is not a predictive marker of neurological outcome in moderate to severe traumatic brain injury ( tbi ) . the human has evolved into a complex adaptive system that is dynamic , exhibiting nonlinear relationships , and is acutely affected by many physiological systems . although trauma scoring systems ( for example , injury severity score , revised trauma score and probability of survival ) or physiological scoring methods ( for example , acute physiology and chronic health evaluation ) employ a multitude of pmeters , the use of a single physiological pmeter  for example , arterial hyperoxia    is not predictive for outcome . the hyperoxia detected could be reflective of the therapeutic intervention associated with major trauma , and the subsequent treatment and clinical course would vary after the initial arterial blood oxygen measurement since < 50% of patients underwent intracranial pressure monitoring . rockswold and colleagues reported a mortality of 42% in the control group for severe tbi , similar to the publication by raj and colleagues ( 39% ) , but the addition of hyperoxia results in a significant relative risk reduction for mortality , similar to other published studies . early initiation of brain oxygen protocols  that is , intracranial pressure / cerebral perfusion pressure / partial pressure of brain tissue oxygen ( pbto2 ) [ 5 - 7 ] and pbto2 critical care guide [ 4,8 - 10 ]  have shown mortality reductions   and improved patient neurological outcome , in contrast to delayed implementation , which may not translate into outcome benefits . the addition of oxygen as a therapeutic tool would necessitate multimodality invasive neurological monitoring in all patients with severe tbi since the fraction of inspired oxygen and airway pressures ( that is , positive end - expiratory pressure or pressure support ) would need to be carefully titrated against pbto2 levels . the deleterious effects of eubaric hyperoxia ( that is , adult respiratory distress syndrome , atelectasis , ventilation / perfusion mismatch ) have been postulated , which may be due to concomitant pulmonary contusion , aspiration or even high ventilator pressures , but have not been substantiated by clinical experience [ 3 - 5,9 ] . indeed , immediately improves pbto2 , reducing lactate levels and infarct size , and exhibits neuroprotective properties . high airway pressure of barotraumas , previously implicated in lung injury , has been refuted by rockswold and colleagues who demonstrated the safety and efficacy of eubaric and hyperbaric oxygen therapy in the management of acute tbi in a randomized control study . specifically , bronchial alveolar lavage revealed no differences in interleukin levels and , rather than toxicity , microdialysis data revealed the neuroprotective effects of oxygen in both the normal and the injured brain . in conclusion , one has to differentiate between hyperoxia ( detected in laboratory tests ) with its potential association with clinical outcome , and the use of eubaric or hyperbaric oxygen as a therapeutic tool . in the former , a single episode of hyperoxia may have shown an association with mortality as reported in this study , but it would rarely prove causality . in the latter , the high therapy intensity level employed with brain oxygen protocols , of which eubaric hyperoxia is critical , requires invasive monitoring with careful goal - directed oxygen titration . the emerging clinical experience demonstrates that hyperoxia is safe and beneficial to the brain , and does not injure the lung as previously feared . pbto2 : partial pressure of brain tissue oxygen ; tbi : traumatic brain injury pkn served as a scientific advisor for integra neurosciences , plainsboro , nj , usa , who manufactured the neuromonitoring devices between 2001 and 2010 . pkn served as a scientific advisor for integra neurosciences , plainsboro , nj , usa , who manufactured the neuromonitoring devices between 2001 and 2010 .
controversy exists on the role of hyperoxia in major trauma with brain injury . 
 hyperoxia on arterial blood gas has been associated with acute lung injury and pulmonary complications , impacting clinical outcome . 
 the hyperoxia could be reflective of the physiological interventions following major systemic trauma . despite the standard resuscitation of patients with acute traumatic brain injury , up 
 to 60% demonstrate low brain oxygen upon admission to the icu . 
 while eubaric hyperoxia has been beneficial in experimental studies , clinical brain oxygen protocols incorporating intracranial pressure control , maintenance of cerebral perfusion pressure , and the effective use of fraction of inspired oxygen adjustments to maintain cerebral oxygenation levels > 20 to 25  mmhg have demonstrated mortality reductions and improved clinical outcomes . 
 the risk of low brain oxygen is most acute in the first 24 to 48  hours after injury . 
 the administration of a high fraction of inspired oxygen ( 0.6 to 1.0 ) in the emergency room may be justifiable until icu admission for the placement of invasive neurocritical care monitoring systems . 
 thereafter , fraction of inspired oxygen levels need to be careful titrated to prevent low brain oxygen levels .