Non-invasive Near-infrared Spectroscopy (NIRS) Versus Invasive Licox Intracranial Pressure

Study Overview
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Brief Summary
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Researchers are trying to assess how accurately and safely NIRS non-invasive monitoring can detect changes in intracranial pressure to determine if this noninvasive device can be used instead of invasive monitoring with Licox in the future.

Official Title
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Non-invasive Near-infrared Spectroscopy (NIRS) Versus Invasive Licox Intracranial Pressure Monitoring in Neurocritical Care

Conditions
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Brain Injuries

Intervention / Treatment
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* Device: Licox® Brain Tissue Oxygen Monitoring System
* Device: Near-infrared spectroscopy (NIRS)


Participation Criteria
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Eligibility Criteria
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Inclusion: Subjects with acute brain injury who are age ≥ 18 Glasgow coma scale score (GCS) ≤ 8 Neuroimaging concerning for ICP crises, or have active ICP treatment Have Licox Brain Tissue Oxygen monitor placed as standard of care treatment Exclusion: CNS infection Bleeding diathesis or thrombocytopenia < 50,000 platelets Subjects with subdural hematomas who have had surgical decompression and bone flap removal

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Device Feasibility
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Subjects with acute brain injury<br>Subjects requiring placement of a Licox Brain Tissue Oxygen device for their clinical care will also have Near-infrared spectroscopy (NIRS) monitoring system placed | Device: Licox® Brain Tissue Oxygen Monitoring System<br>* Invasive brain tissue oxygenation monitoring<br>Device: Near-infrared spectroscopy (NIRS)<br>* Non-invasive approach to monitoring brain tissue oxygenation which uses two wavelengths of near infrared light and takes measurements of the ratio of oxyhemoglobin to total hemoglobin<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between changes in Licox and NIRS oxygenation measurements | Licox measures oxygenation in terms of partial pressure (PtO2) and NIRS measures it in terms of saturation (rSO2). The changes in PtO2 versus the changes in rSO2 will be compared for equivalence. | 3 to 5 days of the monitoring duration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between changes in pressure reactivity index and Licox versus NIRS | The pressure reactivity index (PRx) is derived using ICM+ software; the PRx is a correlation coefficient ranging from -1 to +1; PRx > 0 indicates poor autoregulation. We will investigate if PRx correlates with changes in rSO2 as measured by NIRS (if changes in autoregulation correspond with changes in oxygenation). | 3 to 5 days of the monitoring duration |