This is a prospective observational cohort study of adult patients undergoing high-risk surgery at UT Southwestern Medical Center. The study acquires synchronized multimodal neuromonitoring data - including SedLine quantitative EEG (qEEG) extracted from standard-of-care clinical monitoring and, where deployed, Brain4Care (B4C) noninvasive intracranial dynamics data - and links these data to perioperative hemodynamic, medication, laboratory, procedural, and outcome variables. No alteration of routine clinical care occurs. The primary goal is to characterize associations between monitor-derived features and perioperative clinical variables, and to establish a multimodal dataset supporting future analyses of perioperative brain health in high-risk surgical populations.
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.
Study Type
OBSERVATIONAL
Enrollment
300
UT Southwestern Medical Center - Clements University Hospital
Dallas, Texas, United States
Proportion of enrolled cases with analyzable SedLine quantitative EEG (Patient State Index) recording during surgery
Percentage of total enrolled cases yielding analyzable SedLine Patient State Index (PSI) epochs during the intraoperative period. Signal quality assessed by artifact burden and data completeness. Reported as a single proportion (percentage of cases with analyzable PSI data) across surgical case types.
Time frame: Intraoperative period (duration of surgery, typically 2-12 hours)
Proportion of enrolled cases with analyzable Brain4Care extensometry (P2/P1 ratio) recording during surgery
Percentage of total enrolled cases yielding analyzable Brain4Care (B4C) extensometry P2/P1 ratio epochs during the intraoperative period. Signal quality assessed by artifact burden and adequate waveform morphology. Reported as a single proportion (percentage of cases with analyzable B4C data) across surgical case types.
Time frame: Intraoperative period (duration of surgery, typically 2-12 hours)
Correlation between SedLine Patient State Index and intraoperative mean arterial pressure
Spearman correlation coefficient between SedLine-derived Patient State Index (PSI) values and concurrently recorded intraoperative mean arterial pressure. Secondary within-case correlation analyses with vasoactive drug administration epochs, anesthetic transitions, blood loss events, and major surgical epochs will also be reported as correlation coefficients.
Time frame: Intraoperative period through 90 days post-surgery
Correlation between Brain4Care extensometry P2/P1 ratio and intraoperative mean arterial pressure
Spearman correlation coefficient between Brain4Care (B4C) extensometry-derived P2/P1 ratio values and concurrently recorded intraoperative mean arterial pressure. Secondary within-case correlation analyses with vasoactive drug administration epochs, anesthetic transitions, blood loss events, and major surgical epochs will also be reported as correlation coefficients.
Time frame: Intraoperative period through 90 days post-surgery
Incidence of postoperative delirium assessed by Confusion Assessment Method (CAM)
Rate of postoperative delirium as documented by Confusion Assessment Method (CAM) assessments in nursing records during the postoperative hospital stay, reported as incidence (percentage of enrolled patients with at least one positive CAM screen). Secondary analyses will examine associations between intraoperative SedLine PSI or B4C P2/P1 ratio features and postoperative delirium occurrence.
Time frame: In-hospital postoperative period (expected 2-14 days post-surgery)
Proportion of cases with computable cerebrovascular reactivity indices from Brain4Care extensometry and arterial blood pressure data
Percentage of enrolled cases in which cerebrovascular reactivity-related indices can be computed from acquired Brain4Care (B4C) extensometry waveforms and concurrent arterial blood pressure data, reported as a single proportion with characterization of index distributions across surgical populations.
Time frame: Intraoperative period
Functional status at 90 days post-surgery assessed by modified Rankin Scale via medical record review
Functional and neurological status assessed by modified Rankin Scale (mRS) score via medical record review and/or structured contact at up to 90 days from date of surgery. Reported as ordinal mRS score (0-6).
Time frame: 90 days post-surgery
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