Prospective Observational Multimodal Neuromonitoring During High-Risk Adult Surgery

BACKGROUND: Patients undergoing major spine surgery, liver transplantation, on-pump cardiac surgery, major vascular surgery, major thoracic surgery, major abdominal surgery, and neurosurgical craniotomy are exposed to substantial perioperative physiologic stress, including hemodynamic instability, blood loss, cardiopulmonary bypass, and procedure-specific periods of altered cerebral perfusion. Quantitative electroencephalography and noninvasive assessments of intracranial dynamics may provide complementary information about brain state and cerebrovascular physiology during these high-risk operations. However, the relationships between monitor-derived features and intraoperative events - including hypotension, anesthetic transitions, major surgical events, and postoperative outcomes - remain incompletely characterized.

DESIGN: Single-center prospective observational cohort study at UT Southwestern Medical Center. SedLine quantitative EEG data are extracted from standard-of-care clinical monitoring for all enrolled subjects. Brain4Care (B4C) noninvasive intracranial dynamics monitoring may additionally be placed as a research device depending on study workflow, patient characteristics, technical feasibility, and clinical context. Either monitoring configuration - SedLine alone or SedLine combined with B4C - constitutes a complete and valid study encounter.

The Moberg Clinical Platform (Moberg Analytics; FDA-cleared multimodal data integration system) serves as the primary data acquisition hub where deployed in the operating room, aggregating synchronized high-resolution physiologic waveforms alongside SedLine and B4C outputs. Where Moberg is unavailable, hemodynamic and physiologic variables are collected retrospectively from the Epic intraoperative anesthesia record.

MONITORING MODALITIES:

Research device placed specifically for this study (where deployed):

- Brain4Care (B4C) extensometry: skull-mounted noninvasive sensor recording cranial compliance-related waveform morphology (P2/P1 ratio, Time to Peak).

Standard-of-care clinical data recorded for research purposes:

• SedLine (Masimo): 4-channel frontal quantitative EEG providing Patient State Index, Spectral Edge Frequency, and exportable raw EDF-format waveforms.
• Moberg Clinical Platform: multimodal physiologic waveform integration including arterial blood pressure, SpO2, ECG, ventilator-derived parameters, temperature, and EtCO2.

DATA MANAGEMENT: Subjects are assigned unique study identifiers. Direct identifiers are removed from analytic datasets. Research data are stored on secure, institutionally approved systems accessible only to IRB-authorized study personnel. De-identified data may be shared with qualified external collaborators under executed data use agreements.