Abstract: Objective To observe the change of the latency and amplitude of auditory-evoked potential P300 after oxygen inhalation.Methods 27 healthy male academicians were included. They were divided into control group (n=12) and experiment group (n=15) according to the random numerical table, and they were blinded about groups. All subjects in the experiment group inhaled pure oxygen while air in the control group through a mask for 60 minutes. EEG was recorded when an auditory Oddball paradigm was performed during following
4 periods: before oxygen inhalation (pre0), inhale oxygen (air in control) for 20 minutes (Oxy20) and 50 minutes (Oxy50), 30 minutes after oxygen inhaled (post30). The latency and amplitude of P300 from target stimuli were calculated. Results The latency of P300 was longer at Oxy20 as (358.58±15.32) ms, Oxy50 as (353.42±9.41) ms and post30 as (354.10±10.42) ms than at pre0 as (335.91±15.40) ms in the control group (P<0.01). The latency of P300 was shorter at Oxy50 as (319.17±14.34) ms, and post30 as (318.50±13.87) ms than at pre0 as (332.98±14.63) ms in the experiment group (P<0.05). The latency was shorter in the experiment group than in the control group at Oxy20,Oxy50 and post30 (P<0.01). The amplitudes were stable in the control group (P<0.05). The amplitude was lower at post30 as (2.41±0.64) μV than at pre0 as (5.49±0.89) μV in the experiment group (P<0.05). Conclusion Oxygen inhalation shortens the latency of P300, and decreases the amplitude in the similar trend with the prolongation of oxygen inhalation.

Key words: oxygen inhalation, auditory evoked potential, P300, latency, amplitude