BIS for monitoring depth of anesthesia is usually obtained unilaterally. Obtaining BIS bilaterally revealed side differences in previous studies. This study investigates the incidence of clinically relevant side differences of BIS during maintenance and emergence from anesthesia for ENT surgery in both adults and children.

BIS was measured bilaterally in 42 adults and 46 children during ENT surgery under general anesthesia using two BIS-Monitors. Side differences of more than 10% were defined as BIS asymmetries. An increase of BIS of more than 10% from the value at the time of finishing anesthesia administration on only one side followed by movement after stimulation was defined as clinically relevant.

Inclusion Criteria:Children and adults during anesthesia for ENT surgery -

Exclusion Criteria:Neurologic or psychiatric disease

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Children and adults during anesthesia for ENT surgery