Carbogen inhalation during non-convulsive status epilepticus: A quantitative exploratory analysis of EEG recordings

• Published in: PloS one Vol. 16; no. 2; p. e0240507
• Main Authors: Ramaraju, S, Reichert, S, Wang, Y, Forsyth, R, Taylor, P N
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03-02-2021; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Carbon dioxide; Care and treatment; Computer and Information Sciences; Diagnosis; Electroencephalography; Engineering and Technology; Health aspects; Medicine and Health Sciences; Oxygen; Physical Sciences; Physiological aspects; Research and Analysis Methods; Status epilepticus; United Kingdom
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0240507

To quantify the effect of inhaled 5% carbon-dioxide/95% oxygen on EEG recordings from patients in non-convulsive status epilepticus (NCSE).
Five children of mixed aetiology in NCSE were given high flow of inhaled carbogen (5% carbon dioxide/95% oxygen) using a face mask for maximum 120s. EEG was recorded concurrently in all patients. The effects of inhaled carbogen on patient EEG recordings were investigated using band-power, functional connectivity and graph theory measures. Carbogen effect was quantified by measuring effect size (Cohen's d) between "before", "during" and "after" carbogen delivery states.
Carbogen's apparent effect on EEG band-power and network metrics across all patients for "before-during" and "before-after" inhalation comparisons was inconsistent across the five patients.
The changes in different measures suggest a potentially non-homogeneous effect of carbogen on the patients' EEG. Different aetiology and duration of the inhalation may underlie these non-homogeneous effects. Tuning the carbogen parameters (such as ratio between CO2 and O2, duration of inhalation) on a personalised basis may improve seizure suppression in future.