ROS in TBI Patients in Relation to Level of Oxygenation.

Study Overview
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Brief Summary
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This project an observational study performed on patients with severe Traumatic Brain Injury (TBI) treated at Neurosurgical ICU (NICU) at Karolinska University Hospital. The purpose of this study is to evaluate the effects of various oxygenation levels on production rate of Reactive Oxygen Species (ROS) in patients with severe traumatic brain injury (TBI). The patients will be included in the study after the placement of intracranial monitoring device consisting of intracranial pressure gage (Codman), microdialysis (MD), and Licox oxygen electrode for measurement of partial pressure of oxygen in brain tissue (pBtO2). Intracranial monitoring is inserted on clinical indications and is used for early detection of deleterious processes in brain tissue such as hypoxia or hypoperfusion and for purpose of guiding of given therapies such as cerebral perfusion pressure (CPP), oxygenation, dosage of vasoactive drugs etc. Despite the technical possibilities to monitor all these physiological parameters, there are no clear guidelines how to interpret the MD and pBtO2 data and implement it in clinical decision making. One of the controversies deals with optimization of oxygen levels: some authors point out the importance of adequate brain tissue oxygenation, whereas other researchers are worried about the possible negative effects of excessive oxygen levels such as increased production of ROS or facilitating pulmonary atelectasis, contributing to adverse outcome. The purpose of this study is to investigate the effect of various oxygenation levels on ROS production in TBI patients. This pilot study is designed to measure short-lived ROS in blood and microdialysis fluid samples of TBI patients during alternating periods of normal vs temporarily increased oxygenation levels under normobaric conditions (normal atmospheric pressure).

Official Title
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Formation of Reactive Oxygen Species in Patients With Severe Traumatic Brain Injury in Normal vs Increased Oxygenation.

Conditions
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Systemic Oxygenation vs ROS Formation in TBI Patients

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Severe isolated TBI (GCS<8, AIS =<3), CT-verified TBI (tSDH,tEDH, tSAH, contusion bleedings) caused by blunt or penetrating trauma. Established intracranial monitoring (ICP, MD, LiCox pBtO2) at NICU. Age >= 18 Time from trauma from 0 to 4 days. Informed consent from Close relative. Systemic hyperoxygenation can be used in patients with pBtO2 <20 mmHg, based on clinical decision. Exclusion Criteria: Major extracranial injury, AIS >3 Brain dead or expected survival <24 hours Pregnancy Respiratory insufficiency FiO2> 40% 6. No consent from relative.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ROS concentrations in blood | ROS concentrations in patient´s blood will be measured repeatedly at normal systemic oxygenation and at increased oxygenation if necessary. | 7 days | 
| Markers of oxidative stress | Indirect markers of oxydative stress, as MDA (Malondialdehyde) and Isoprostane F2, in relation to level of systemic oxygenation. | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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TBI, ROS, oxygenation, cerebral monitoring, neurointensive care