Influences of Hypoxia on Auditory Evoked Potentials of Conscious Humans

Early cortical auditory evoked potentials (AEP) from eleven volunteers undergoing an arterial oxygen desaturation procedure have been recorded and analysed. During the procedure the arterial oxygen saturation was decreased from 100% gradually down to 70%. Changes of the latency and amplitude of the AEP could be detected on the conscious subjects thus excluding any influences of anaesthesia. It was found that as oxygen desaturation went down the latency increased significantly and the amplitude also slightly increased but with no statistic significance. The latency parameters, especially Pb latency, are more sensitive to hypoxia than the amplitude parameters. The changes are similar to the effect of induction of anaesthesia