Prevalence of Isoelectric Electroencephalography Events in Infants and Young Children Undergoing General Anesthesia

Abstract

BACKGROUND: In infants and young children, anesthetic dosing is based on population pharmacokinetics and patient hemodynamics not on patient-specific brain activity. Electroencephalography (EEG) provides insight into brain activity during anesthesia. The primary goal of this prospective observational pilot study was to assess the prevalence of isoelectric EEG events—a sign of deep anesthesia—in infants and young children undergoing general anesthesia using sevoflurane or propofol infusion for maintenance. METHODS: Children 0–37 months of age requiring general anesthesia for surgery excluding cardiac, intracranial, and emergency cases were enrolled by age: 0–3, 4–6, 7–12, 13–18, and 19–37 months. Anesthesia was maintained with sevoflurane or propofol infusion. EEG was recorded from induction to extubation. Isoelectric EEG events (amplitude <20 µV, lasting ≥2 seconds) were characterized by occurrence, number, duration, and percent of isoelectric EEG time over anesthetic time. Associations with patient demographics, anesthetic, and surgical factors were determined. RESULTS: Isoelectric events were observed in 63% (32/51) (95% confidence interval [CI], 49–76) of patients. The median (interquartile range [IQR]) number of isoelectric events per patient was 3 (0–31), cumulative isoelectric time per patient was 12 seconds (0–142 seconds), isoelectric time per event was 3 seconds (0–4 seconds), and percent of total isoelectric over anesthetic time was 0.1% (0%–2.2%). The greatest proportion of isoelectric events occurred between induction and incision. Isoelectric events were associated with higher American Society of Anesthesiologists (ASA) physical status, propofol bolus, endotracheal tube use, and lower arterial pressure during surgical phase. CONCLUSIONS: Isoelectric EEG events were common in infants and young children undergoing sevoflurane or propofol anesthesia. Although the clinical significance of these events remains uncertain, they suggest that dosing based on population pharmacokinetics and patient hemodynamics is often associated with unnecessary deep anesthesia during surgical procedures.

Electroencephalographic assessment of infant spinal anesthesia: A pilot prospective observational study

“…Several studies in older adults have shown that intraoperative burst suppression under GA is associated with an increased risk of postoperative cognitive dysfunction. [18][19][20] Though burst suppression occurs in children under multiple modalities of GA 21 at a rate of approximately 50%-60%, [22][23][24] potential consequences of this remain unknown. Our data collection to date does not show any evidence of burst suppression after administration of SA in infants, suggesting SA may be associated with less risk for this pattern of brain activity and any potential morbidities therefrom.…”

A retrospective study of electroencephalography burst suppression in children undergoing general anesthesia

“…The patients who received propofol boluses had more possibilities to develop burst suppression, which may be attributed to the administration of high doses of propofol to achieve deeper anesthesia and adapt the level of nociceptive stimulation during surgery. Administration of an additional propofol bolus, either before or after intubation, can result in either enhancement of the slow oscillation or the conversion of the slow oscillation into burst suppression 7,24 . Overall, propofol boluses, use of sevoflurane, and lower arterial pressure during anesthesia were associated with burst suppression events.…”

Why do We Use the Concepts of Adult Anesthesia Pharmacology in Developing Brains? Will It Have an Impact on Outcomes? Challenges in Neuromonitoring and Pharmacology in Pediatric Anesthesia

“…In a recent study in children 0–37 months of age requiring general anesthesia for noncardiac or intracranial surgery using sevoflurane or propofol infusion, in 63% of the patients, an episode of isoelectricity was observed, more related to high ASA status patients [ 60 ].…”