Target-controlled induction with 2.5% sevoflurane does not avoid the risk of electroencephalographic abnormalities

Area of Science:

• Anesthesiology
• Neurophysiology

Background:

• Epileptiform discharges (ED) are a known risk during sevoflurane anesthesia induction, particularly in young females and with high concentrations.
• Understanding factors influencing ED occurrence is crucial for patient safety.

Purpose of the Study:

• To investigate if a low sevoflurane concentration (2.5%) reduces the incidence of ED in female patients undergoing anesthesia induction.

Main Methods:

• A prospective randomized study involving 34 female patients undergoing minor gynecological surgery.
• Two induction groups: Group A (manual 8% then 2.5% sevoflurane) and Group B (target-controlled 2.5% sevoflurane).
• Continuous electroencephalogram (EEG) monitoring during induction and analyzed by a blinded neurophysiologist.

Main Results:

• ED occurred in 15% of patients (1 in Group A, 4 in Group B), with no statistically significant difference between groups (P>0.05).
• Median ED onset was 303 seconds, with a median duration of 13 seconds.
• Fifteen patients exhibited abnormal movements unrelated to EEG abnormalities.

Conclusions:

• A low target sevoflurane concentration of 2.5% is insufficient to completely prevent ED in young female patients.
• Anesthesia induction with sevoflurane in this demographic requires cautious application due to potential ED occurrence.