Changes in otoacoustic emissions by inducation dose of propofol

ABSTRACT

The effects of propofol on distortion product otoacoustic emission [DPOAE] recordings were evaluated and compared in the awake and anaesthetized state in a group of twenty ASA I patients undergoing elective surgery of the nose, paranasal sinuses or soft tissue of the neck and throat. We report a statistically non-significant reduction [P> 0.05] in the amplitudes of DPOAEs across all frequency bands following induction doses of propofol. The greatest reduction occurred in the 2 kHz region, where the DPOAE amplitudes were significantly positively correlated with the diastolic blood pressure [r=0.955, P < 0.05]. Our data support the hypothesis that anaesthetic agents produce a frequency-specific attenuation of the DPOAE amplitude and strongly suggest that DPOAE amplitude changes depend not only on the anaesthetic agents pharmacological properties, but on the induced haemodynamic changes as well