Association Between Early Hyperoxia and Worse Outcomes After Traumatic Brain Injury

Abstract

Objective: To investigate the relationship between oxygenation and short-term outcomes in patients with traumatic brain injury (TBI). Design: Logistic regression analysis was used to determine whether average high (Ͼ200 mm Hg) or low (Ͻ100 mm Hg) PaO 2 levels within the first 24 hours of hospital admission correlated with patient outcomes relative to patients with average PaO 2 levels between 100 and 200 mm Hg. Setting: Level 1 trauma center. Patients: We retrospectively reviewed 1547 consecutive patients with severe TBI who survived past 12 hours after hospital admission. Main Outcome Measures: We measured mortality, intensive care unit length of stay, hospital length of stay, and discharge Glasgow Coma Scale (GCS) score. Results: Of the 1547 patients, 77% were male and 89% sustained blunt trauma. Mean (SD) age, admission GCS score, and Injury Severity Score were 41.3 (20.6) years, 8.3 (4.7), and 31.9 (12.5), respectively. Mean (SD) intensive care unit length of stay and hospital length of stay were 8.7(10.5) days and 13.8(13.7) days, respectively. Mean (SD) discharge GCS score was 10.1(4.7). The mortality rate was 28%. After controlling for age, sex, Injury Severity Score, mechanism of injury, and admission GCS score, patients with high PaO 2 levels had significantly higher mortality and lower discharge GCS scores than patients with a normal PaO 2 (P Ͻ.05). Patients with low PaO 2 levels also had increased mortality (P Ͻ.05). Conclusions: Hyperoxia within the first 24 hours of hospitalization is associated with worse short-term functional outcomes and higher mortality after TBI. Although the mechanism for this has not been completely elucidated, it may involve hyperoxia-induced oxygenfree radical toxicity with or without vasoconstriction. Hyperoxia and hypoxia were found to be equally detrimental to short-term outcomes in patients with TBI. A narrower therapeutic window for oxygenation may improve mortality and functional outcomes.

Impact of pre-hospital oxygenation and ventilation status on outcome in patients with isolated severe traumatic brain injury

“…(5,6) At first glance, our findings from the study do not support the thesis that pre-hospital hypoxia and hyperoxia are detrimental to the injured brain. At this point we would like to emphasize that interpretation of our data should be put into perspective of the small sample size.…”

“…Some studies have found a beneficial effect with improved physiological parameters, (3,4) while others have reported worsened functional outcome. (5,6) Endotracheal intubation (ETI) using a rapid sequence intubation (RSI) protocol was introduced to pre-hospital Emergency Medical Services (EMS) to avoid hypoxia and to secure the airway, thus preventing aspiration in patients with TBI. Aggressive early airway management increases the success of pre-hospital ETI, but surprisingly also increases the mortality rate.…”

Sanguinate's effect on pial arterioles in healthy rats and cerebral oxygen tension after controlled cortical impact

“…Early intervention to alleviate decreased PbtO 2 following TBI is a critical step as the degree and duration of low PbtO 2 is related to neurological outcome (Brenner et al, 2012;Chi et al, 2006;Chowdhury et al, 2014). In animal studies of TBI, increasing the inspired oxygen concentration enhanced aerobic metabolism by increasing brain oxygen pressure (Menzel et al, 1999a;Menzel et al, 1999b).…”

Hyperoxia may be related to delayed cerebral ischemia and poor outcome after subarachnoid haemorrhage

“…During mechanical ventilation, hyperoxia is not uncommon in the emergency room and intensive care unit during the management of SAH. Recent studies in patients after cardiac arrest and traumatic brain injury have suggested that hyperoxia is associated with worse outcomes 2 3. Contrarily, others have suggested that hyperoxia may be of therapeutic benefit for patients with traumatic brain injury and ischaemic stroke 4–7.…”