Quantitative Validation of a Simplified 4-Lead Electroencephalogram Montage for Neuromonitoring in Post-Cardiac Surgery Intensive Care Unit Patients.

OBJECTIVE

Neurologic complications after cardiac surgery are common and associated with high morbidity and mortality. Continuous electroencephalography (cEEG) provides the reference standard for brain monitoring, but the standard 19-lead setup is difficult to implement routinely in the intensive care unit (ICU). Simplified EEG montages derived from high-density recordings were computationally evaluated to identify a configuration that preserves quantitative EEG (qEEG) fidelity for global brain state trend assessment at the bedside.

DESIGN

A retrospective, observational validation study.

SETTING

Single-center cardiac surgical ICU.

PARTICIPANTS

Twenty-six patients admitted to the ICU for at least 24 hours following cardiac surgery with cardiopulmonary bypass, all under deep sedation (Richmond Agitation-Sedation Scale -4) during EEG recording.

INTERVENTIONS: Computational extraction of reduced-lead configurations (2-lead, three 4-lead combinations, and 6-lead) from 16-lead reference EEG recordings.

MEASUREMENTS AND MAIN

RESULTS

Both 4-lead and 6-lead configurations showed good to excellent agreement with the reference. The 4-lead F3+F4+F7+F8 montage achieved excellent reliability intraclass coefficient (>0.9) for 9 of 10 qEEG parameters, with performance comparable to the 6-lead configuration. Bland-Altman analysis showed small bias and acceptable 95% limits of agreement for key parameters.

CONCLUSIONS

A computationally derived 4-electrode montage (F3, F4, F7, and F8) demonstrates close agreement with the 16-electrode reference for global qEEG trend parameters in deeply sedated post-cardiac surgery patients. These findings provide a computational basis for designing a future standalone reduced-electrode acquisition system. Prospective validation with independent hardware is required before clinical deployment, and diagnostic performance for focal events remains to be established.