Study of Pharmacological and Clinical Correlates of Frontal Cortical Electroencephalographic (EEG) Signal During the Induction, Maintenance and Emergence Phases of Anesthesia in Children

Overview

Using data from a prospective cohort of children receiving general anaesthesia for surgery, this project will collect pharmacological correlates (doses and timing of administration of anaesthetic drugs) and clinical correlates (stimulations including nociceptive stimulation, possible responses such as movement/resumption of spontaneous ventilation during maintenance of anaesthesia/tachycardia/high blood pressure) of patients during the three phases of anesthesia (induction, maintenance, emergence).

The usual practice of general anesthesia in children is based on the prescription of anesthetic drugs with doses adapted to weight and neurological examination focusing on the functions of the brainstem. Each patient has a specific sensitivity to anesthetic drugs (inter-individual pharmacokinetic and pharmacodynamic variability). This inter-individual variability is likely to cause anesthesia that is too deep or, conversely, too light, which can be difficult to anticipate and can cause complications, particularly hemodynamic and neurocognitive. Because of the pharmacokinetics of anesthetic drugs, once an overdose is present, it will be relatively prolonged (several minutes). This is the correction of overdose. In adults, monitoring of anesthesia adequacy is performed by EEG signal analysis (mainly BIS (Bispectral Index) monitor, Medtronic, Dublin, Ireland). This practice is not very common in children. Since 2020, an EEG monitor (Sedline, Masimo, Irvine, California, USA) allows the estimation of the adequacy of anesthesia in children based on an EEG model (spectral density matrix; double spectrum delta and alpha during the maintenance phase of anesthesia). Nevertheless, the pharmacological correlates (doses and delays in reaching the peak of the effect of drugs) as well as the clinical correlates (loss of verbal contact at induction, responses to nociceptive stimuli during the maintenance of anesthesia, return of brainstem functions in the emerging phase) associated with this double delta/alpha spectrum are not described. In addition, monitor EEG analysis tools cannot correctly describe (in spectral density matrix) the induction and emergence (awakening) phases of general anesthesia. Questions remain about the potentially deleterious effects of general anesthesia in children, especially in children under one year of age. To the extent that general anesthesia is necessary for the performance of the surgical procedure, it is essential to have tools (cortical EEG) that make it possible to adjust the doses of anesthetic drugs to adapt to inter-individual variability. In children, the use of EEG for estimating the adequacy of anaesthesia remains incomplete and imperfect.