Author: Rodrigues A et al.
Anesthesiology. doi:10.1097/ALN.0000000000005696
This prospective cohort study examined 23 mechanically ventilated patients with acute hypoxemic respiratory failure (AHRF) and PaO2/FiO2 <200 mmHg to investigate the impact of sedation on brain activity using the Odds Ratio Product (ORP), an EEG-based measure of the sleep–wake continuum. Continuous EEG monitoring was performed for up to seven days, totaling 1,832 hours of recordings.
A novel EEG pattern, termed EEGUps—never or rarely seen in natural sleep—was identified, accounting for 42% of total recording time and exceeding 50% in certain sedation–opioid combinations. EEGUps were more frequent with higher sedation doses, deeper sedation scores, and certain drug regimens (P ≤ 0.035). Physiologic sleep markers, such as brief wake intrusions, were markedly reduced. Importantly, EEGUps were significantly associated with ICU mortality (P < 0.001).
The authors conclude that continuous intravenous sedation induces distinct, unnatural EEG patterns correlated with sedation depth, drug type, and worse clinical outcomes, suggesting a potential biomarker for sedation-related brain effects in critically ill patients.
References
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Rodrigues A, Subirà C, Bizios A, et al. Anesthesiology. 2025. doi:10.1097/ALN.0000000000005696.
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