[Measurement of the acoustically evoked stapedius reflex in intubation anesthesia]

The threshold of the acoustically elicited stapedial reflex was measured in 45 persons with normal hearing aged 13-34 years. The intravenous barbiturate given for induction of general anaesthesia was found to raise the reflex threshold by an average of 15 dB. Ketanest and Halothane raise the reflex threshold by an average of 24 dB and 28 dB respectively. The ipsilateral reflex response was altered less by general anaesthesia than the contralaterally evoked response. The stapedial reflex can thus be measured under general anaesthesia if sedation fails to control disturbed and severely handicapped children.