Electroencephalograms in children during isoflurane anesthesia

Area of Science:

• Anesthesiology
• Pediatric Neurology
• Neurophysiology

Background:

• Isoflurane is a common anesthetic agent used in pediatric patients.
• Understanding age-related changes in electroencephalogram (EEG) patterns during anesthesia is crucial for safe practice.
• Previous studies have not fully characterized the specific EEG changes with age under varying isoflurane concentrations.

Purpose of the Study:

• To investigate age-related alterations in electroencephalogram (EEG) patterns during isoflurane anesthesia in children.
• To determine the influence of different isoflurane concentrations and nitrous oxide on these EEG changes.
• To establish normative EEG amplitude and burst suppression data for pediatric populations.

Main Methods:

• Electroencephalograms (EEG) were recorded from 55 children aged 1 month to 14 years under isoflurane anesthesia.
• Children were divided into six age groups, and EEG was assessed at 1.5 Minimum Alveolar Concentration (MAC), 1.0 MAC, and 1.0 MAC with nitrous oxide.
• Controlled mechanical ventilation was maintained, with end-tidal CO2 levels kept between 35-40 mmHg.

Main Results:

• The incidence of burst suppression at 1.5 MAC was significantly lower in children aged 6 months to 6 years compared to younger or older groups (P<0.05).
• Except for infants under 6 months, mean maximum EEG amplitude at 1.0 MAC was 2-3 times higher in children than in adults.
• Children aged 3-6 years exhibited the highest mean maximum amplitude (427.0±83.5 μV).

Conclusions:

• Age significantly modulates EEG responses to isoflurane anesthesia in children.
• Specific age ranges show distinct patterns of burst suppression and EEG amplitude, suggesting developmental differences in anesthetic sensitivity.
• These findings provide valuable insights for optimizing anesthetic management and interpreting EEG in pediatric patients.