Abstract
BACKGROUND: The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen saturation (SjvO2), and/or arterial-venous difference (AVD) for glucose, lactate, and oxygen in patients with severe TBI.
METHODS: Seventeen intubated TBI patients (age 16-74 years) were sedated using continuous propofol infusion. All patients received intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring in addition to MD, PbtiO2 and/or SjvO2. Up to 10 days post-injury, ICP, CPP, PbtiO2 (51 NWTs), MD (49 NWTs), and/or SjvO2 (18 NWTs) levels during propofol sedation (baseline) and NWT were compared. MD was evaluated at a flow rate of 1.0 μL/min (28 NWTs) or the routine 0.3 μL/min rate (21 NWTs).
RESULTS: The NWT increased ICP and CPP levels (p < 0.05). Compared to baseline, interstitial levels of glucose, lactate, pyruvate, glutamate, glycerol, and the lactate/pyruvate ratio were unaltered by the NWT. Pathological SjvO2 (<50 % or >71 %; n = 2 NWTs) and PbtiO2 (<10 mmHg; n = 3 NWTs) values were rare at baseline and did not change following NWT. Finally, the NWT did not alter the AVD of glucose, lactate, or oxygen.
CONCLUSIONS: The NWT-induced stress response resulted in increased ICP and CPP levels although it did not negatively alter focal neurochemistry or cerebral oxygenation in TBI patients.
Original language | English |
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Pages (from-to) | 413-26 |
Number of pages | 14 |
Journal | Neurocritical Care |
Volume | 20 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2014 Jun |
Free keywords
- Adolescent
- Adult
- Aged
- Arousal
- Brain
- Brain Injuries
- Consciousness Disorders
- Critical Care
- Energy Metabolism
- Female
- Humans
- Hypnotics and Sedatives
- Intracranial Pressure
- Jugular Veins
- Male
- Microdialysis
- Middle Aged
- Neurologic Examination
- Oxygen
- Stress, Physiological
- Trauma Severity Indices
- Young Adult
- Journal Article
- Research Support, Non-U.S. Gov't