Clinical trial NCT02810145: Cerebral Desaturation in Traumatic Brain Injury
Official title: The Incidence and Magnitude of Cerebral Desaturation in Traumatic Brain Injury (TBI) Patients
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Brain Injuries
Keywords: traumatic brain injury
cerebral desaturation
intensive care
hemodynamics
Loss
Consciousness
Lead sponsor: University of Manitoba
Sponsor class: OTHER
First posted: 2016-06-22
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Adult patients admitted to the Surgical/Trauma ICU at Health Sciences Centre, Winnipeg with a severe TBI (Glasgow coma score \< or = 8).

Brief summary: We will determine the incidence and magnitude of cerebral desaturation in TBI. Adult patients (18 years and older) admitted to the Surgical/Trauma Intensive Care Unit (ICU) at the Health Sciences Center with a severe TBI will have cerebral oximetry monitoring instituted within 12 hours of admission and continuing for 72 hours after placement. Decreases in regional cerebral oxygenation will be correlated with ICU hemodynamic parameters including mean arterial pressure, intracranial pressure, and arterial oxygen and carbon dioxide tension.

Detailed description: In patients who have suffered a traumatic brain injury, the current management strategies focus on the maintenance of normotension and normoxia and a normalized intracranial pressure (ICP). Recent evidence calls into question the utility of ICP monitoring in these patients. More advanced cerebral monitoring such as the use of invasive brain tissue oxygen monitors have not found their way into widespread clinical practice. Cerebral oximetry monitoring utilizes the different absorption characteristics of oxygenated and deoxygenated blood to measure global brain oxygen levels.

While clinicians have no ability to reverse the primary brain injury, they can mitigate the secondary injury effects, namely hypoxia and hypotension. It is well known that maintaining normal blood pressure and oxygen saturation can prevent secondary brain injury. However, it is also known that despite the appearance of normal hemodynamics, brain oxygen delivery in the ischemic penumbra may be inadequate. This secondary brain injury is likely related to decreases in cerebral oxygenation (rSO2).

There have been a number of studies that have examined a link between intraoperative decreases in rSO2 and adverse perioperative outcome. These studies suggest that decreases in rSO2 may be related to both adverse neurologic and non-neurologic sequelae. All of these studies suffer from similar flaws, however. They are typically small in size, have varying definitions of what constitutes a cerebral desaturation event, and have incompletely, or poorly defined complications. Also lacking is a mechanistic explanation for the cerebral desaturations as peripheral oxygen saturation typically remains near normal.

The brain can be considered the organ of highest priority when it comes to tissue hypoperfusion during shock states. When oxygen delivery to the brain is decreased below a critical value, cerebral desaturations occur. In the context of TBI, cerebral desaturation may be the hallmark of secondary injury. Consistent with this hypothesis, in the largest cerebral oximetry trial to date, Murkin and colleagues discovered that the incidence and magnitude of cerebral desaturations was related to major non-neurologic organ morbidity.

Two questions arise in relation to this prior research. First, are these cerebral desaturations causative of the adverse outcomes, and second if these desaturations were treated (i.e. if cerebral oxygenation was normalized) would outcome be improved (i.e. or are cerebral desaturations merely an epiphenomenon)?

This study will determine the incidence and severity of cerebral desaturation in traumatic brain injury patients admitted to the Surgical Intensive Care Unit. We will examine factors associated with cerebral desaturation such as ICP and blood pressure, and will determine if decreases in rSO2 are helpful in prognostication of traumatic brain injury.

Eligibility criteria: Inclusion Criteria:

* Adults 18 years of age or older admitted to ICU with severe TBI (Glasgow coma score \<or=8)

Exclusion Criteria:

* None

Primary outcomes:
measure: Incidence of cerebral desaturation
timeFrame: 72 hours
measure: Magnitude of cerebral desaturation
timeFrame: 72 hours
Secondary outcomes:
measure: Association between cerebral desaturation and intracranial pressure
timeFrame: 72 hours
measure: Association between cerebral desaturation and mean arterial pressure
timeFrame: 72 hours
measure: Association between cerebral desaturation and arterial oxygenation
timeFrame: 72 hours
measure: Association between cerebral desaturation and arterial carbon dioxide concentration
timeFrame: 72 hours
Other outcomes:
Locations:
city: Winnipeg
country: Canada
facility: University of Manitoba
state: Manitoba
Study officials:
affiliation: University of Manitoba
name: Duane J. Funk, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Fischer GW. Recent advances in application of cerebral oximetry in adult cardiovascular surgery. Semin Cardiothorac Vasc Anesth. 2008 Mar;12(1):60-9. doi: 10.1177/1089253208316443. Epub 2008 Apr 7.
citation: Casati A, Fanelli G, Pietropaoli P, Proietti R, Tufano R, Danelli G, Fierro G, De Cosmo G, Servillo G; Collaborative Italian Study Group on Anesthesia in Elderly Patients. Continuous monitoring of cerebral oxygen saturation in elderly patients undergoing major abdominal surgery minimizes brain exposure to potential hypoxia. Anesth Analg. 2005 Sep;101(3):740-747. doi: 10.1213/01.ane.0000166974.96219.cd.
citation: Fischer GW, Lin HM, Krol M, Galati MF, Di Luozzo G, Griepp RB, Reich DL. Noninvasive cerebral oxygenation may predict outcome in patients undergoing aortic arch surgery. J Thorac Cardiovasc Surg. 2011 Mar;141(3):815-21. doi: 10.1016/j.jtcvs.2010.05.017. Epub 2010 Jun 25.
citation: Kazan R, Bracco D, Hemmerling TM. Reduced cerebral oxygen saturation measured by absolute cerebral oximetry during thoracic surgery correlates with postoperative complications. Br J Anaesth. 2009 Dec;103(6):811-6. doi: 10.1093/bja/aep309.