This study is a randomized controlled trial to evaluate whether EEG-guided calibration of inhalation agents can reduce occurrence of EEG discontinuity in infants during general anesthesia.

This is a study for comparison of incidence of EEG discontinuity during general anesthesia using sevoflurane. EEG guidance group will receive calibration of fraction of inhalational sevoflurane according to components of slow wave and delta wave of raw EEG. Control group will receive conventional management of anesthesia according to vital signs.

Inclusion Criteria:

• Infants who were born as full-term (>37 weeks postconception) and are equal to or less than 12 month old who were scheduled to undergo surgery under general anesthesia using inhalation agents.
• Belongs to American Society of Anesthesiologists Physical Status 1 or 2

Exclusion Criteria:

• Infants who were born less than 37 weeks postconception or has history of mechanical ventilation immediately after birth
• Presence of any genetic disease, chromosomal anomaly or congenital anomaly that can affect brain development
• Presence of any disease or disability in central nervous system
• History of trauma at head or surgery on brain
• History of hypersensitivity to any anesthetic agents
• Status of sedation or endotracheal intubation before induction of anesthesia
• Inability to attach probes for EEG monitoring
• Expectation of operation time as less than 5 minutes
• Other conditions that researchers regard as inappropriate for enrollment