Study of Cerebral Tissue Oxygenation During Transfusion in Traumatic Brain Injury
Condition: TBI (Traumatic Brain Injury); Acute Brain Injuries
MeSH terms: Brain Injuries; Brain Injuries, Traumatic; Wounds and Injuries
Study type: Observational

Summary: 
      This proposal aims to provide some objective, non-invasively achieved, physiologically
      relevant data in order to provide some rational basis for decision-making for transfusion in
      sTBI. Specifically this proposal is an observational study of transfusion and brain tissue
      saturation in sTBI patients. The results will illustrate to what degree brain tissue
      oxygenation is critically dependent on the degree of anemia in sTBI and help in the decision
      of whether transfusion might be helpful.
    

Detailed description: 
      While there are studies that have invasively monitored cerebral saturation and brain tissue
      oxygen in severe traumatic brain injury (sTBI) patients, there are none using non-invasive
      cerebral saturation monitoring in TBI patients undergoing packed red blood cell (pRBC)
      transfusion. To date, all published studies have involved invasive monitoring with their
      concomitant potential side effects. Insertion of invasive probes and monitors has several
      risks and side effects including bleeding, local trauma and brain damage, and infection.
      Furthermore, they have limited utility as information is restricted to the region of the
      brain surrounding the probe, as opposed to a more global picture. We therefore propose an
      observational study using non-invasive near infrared spectroscopy to monitor brain tissue
      oxygen during the transfusion of packed red blood cells.

      Primary Hypothesis:

      • Improved oxygen delivery causes improved brain tissue oxygen saturation.

      Testable Hypothesis:

      • The transfusion of packed red blood cells resulting in a change in the hemoglobin in the
      70- 100g/L range, will be associated with an increase in cerebral tissue oxygen saturation
      measured by near infrared spectroscopy in severe traumatic brain injured patients.

      Primary Aims:

      • Evaluate the applicability of a 4 wavelength near-infrared spectroscopy (NIRS) to monitor
      the cerebral oximetry in traumatic brain injury patients. Observe the trend of cerebral
      tissue oxygenation saturations (StO2) before, during and after a blood transfusion in TBI
      patients.

      Secondary Hypothesis:

        -  We hypothesize that as pRBCs are transfused there will be a plateau (i.e. hemoglobin
           threshold) beyond which no increase in cerebral tissue oxygenation will occur.

        -  There will be lag time between the increase in systemic hemoglobin and the improvement
           of cerebral tissue oxygenation.

      Secondary Aims:

        -  To correlate the systemic hemoglobin level with cerebral tissue oxygenation saturation
           as pRBCs are transfused.

        -  Correlation of non-invasive cerebral tissue oxygenation saturation measurements with
           invasive brain tissue oxygen tension (if available).
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        30 Patient with clinical diagnosis of severe TBI and GCS <9 and Age > 18 years old
      
Keywords: Red Cell Transfusion; Cerebral tissue oxygenation; Traumatic brain injury