Quantitative burst suppression on serial intermittent EEG in refractory status epilepticus

Area of Science:

• Neurology
• Clinical Neurophysiology
• Critical Care Medicine

Background:

• Refractory status epilepticus (RSE) management requires optimal EEG suppression, but the ideal level remains unclear.
• Centers without continuous EEG often use serial intermittent recordings, leading to uncertainty and potentially aggressive suppression.
• Quantitative Burst Suppression Ratio (QBSR) is a metric derived from EEG data.

Purpose of the Study:

• To investigate the association between QBSR from serial intermittent EEG recordings and patient outcomes in RSE.
• To determine if the depth of EEG suppression correlates with RSE patient prognosis.

Main Methods:

• Retrospective review of EEG and clinical data from adult RSE patients (non-anoxic).
• Calculation of QBSR per 10-second epoch (<3 µV amplitude).
• Multivariate analyses (per-capita, per-session, per-epoch) adjusting for confounders like aSTESS, gender, and anesthetic type/number.

Main Results:

• Initial analysis showed deeper QBSR in the favorable outcome group (p < 0.001).
• Adjusted multivariate analyses revealed no consistent association between QBSR and RSE patient outcome.
• Higher aSTESS correlated with unfavorable outcomes, while more non-barbiturate anesthetic types correlated with favorable outcomes (per-epoch analysis).

Conclusions:

• The depth of EEG suppression, measured by QBSR from serial intermittent EEG, is not associated with RSE patient outcomes.
• Targeting deeper burst suppression in RSE using non-barbiturate anesthetics has limited clinical utility.
• Non-suppressive EEG content may play a role in favorable outcomes, suggesting a need to reconsider EEG monitoring strategies.