EEG Profiles During General Anesthesia : a Comparative Study Between Sevoflurane and Propofol

Hôpital Armand Trousseau73 enrolled

Overview

A cerebral pharmacodynamic feedback may help the anesthesiologist to adjust anesthetics administration. The BIS, which provides a single number resulting from an algorithm calculated from cortical EEG parameters, may play this role.Moreover, halogenated agents and propofol may have different EEG effects, which might interfere on measured BIS values. The aim of this prospective randomized study was to compare, in steady state conditions, the EEG profiles in children anesthetized with sevoflurane (S) or propofol (P) : for both anesthetics, the BIS-concentration relationship and raw EEG were analysed at different levels of general anesthesia.

Children will be prospectively included and randomly assigned in two groups : Propofol (P) Group or Sevoflurane (S) Group. Steady state periods will be performed at a fixed randomized concentration between 2, 3, 4, 5 and 6 mcg/ml of stable Ct P concentration in the P group and between 1,2,3,4,5 % of FeS in the S group. At the end of each steady-state period the BIS value was noted and the relationship between BIS and anesthetic concentrations will be studied using non linear regression. For all steady state periods, EEG traces will be reviewed to determine the presence of epileptiform signs (ES) and spectral EEG signal analysis with fast Fourier transformation (FFT) will be performed.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SCREENING

Masking

SINGLE

Enrollment

Conditions

Anesthesia

Eligibility

Sex: ALLMin age: 5 YearsMax age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * from five to eighteen year of age, ASA 1 or 2, scheduled for middle ear surgery Exclusion Criteria: * obesity (body mass index \> percentile 97); history of cardiac, pulmonary, or renal disease; known neurological or neuromuscular disorders; preoperative administration of medications known to interfere with the central nervous system

Outcomes

Primary Outcomes

Bispectral profiles

For each patient, before surgery and according to the constraints of operating schedule, one or two 10 min steady state periods were performed at a fixed FeS randomized between 1, 2, 3, 4 and 5 % of Sevoflurane in the Sevoflurane group or at a fixed Ct P randomized between 2, 3, 4, 5 and 6 mcg/ml in the propofol group.

Time frame: The average value of BIS is calculated on the last minute of each ten minutes steady state period .

Secondary Outcomes

Incidence of epileptiform EEG signs

Time frame: Last minute of each ten minutes steady state period

Spectral analysis of EEG signal