Effect Of The Treatment With CPAP On Auditory Function In Patients With Severe OSAHS

Objective: Obstructive sleep apnea-hypopnea syndrome(OSAHS)is common and frequently occuring disease in ENT clinical work.The pathophysiological basis of OSAHS is the collapse of upper airway during sleep,leading to apnea and hypopnea,accompanying snore and sleep structure disorder.It is usually associated with a reduction in bood oxygen saturation and the daytime sleepiness and fatigue.Long-term recurrent attacks in patients with OSAHS can result in anoxemia,hypercapnia,and in the last lead to systemic multiple system disease.Aditory system,as part of the nervous system,also be affected.Some clinical researches on the auditory function in patients suffering from OSAHS have been reported,but few of studies on Effect of CPAP on auditory function in patients with OSAHS be explored.So we aim to investigate the auditory feature about patients with severe OSAHS and the effect of CPAP on auditory function by testing pure tone audiometry,tympanometry,auditory brainstem responses(ABR)and distortion product otoacoustic emissions(DPOAE),thus to reveal the changes of auditory function in patients with OSAHS and how much the auditory function of patients with severe OSAHS can be affected by CPAP.Methods: 20 patients(40 ears)which were diagnosed as severe OSAHS were selected as OSAHS group.Choose 12 simple snorers(24 ears)who visited the Department of ENT at the same period as Simple snoring group.12 healthy volunteers(24 ears)without sleep snoring were selected as Normal control group.Make sure that age the three sets of observed objects are age-and sex-matched.Pure tone audiometry,tympanometry,auditory brainstem responses(ABR)and distortion product otoacoustic emissions(DPOAE)were performed in three sets of observed objects at audiometric room(noise <20dB SPL),and the results were recorded.We analysised all the datas with SPSS16.0.In order to ensure the curative effect and treatment compliance,patients who received the CPAP treatment in the OSAHS group were followed up regularly and given pressure titration again on accassion.We ultimately selected 12 subjects(24 ears)who persisted long-term CPAP treatment and have an exact effect.Through three months of treatment on the 12 subjects,Pure tone audiometry,tympanometry,auditory brainstem responses(ABR)and distortion product otoacoustic emissions(DPOAE)were performed again in the same conditions.The inspection results before and after CPAP were compared and analysised by SPSS16.0.Results:1 There were no significant differences of common pure tone auditory thresholds(125~4000Hz)between the OSAHS group and the other groups(P>0.05).The high frequency auditory threshold(8000Hz)of OSAHS group were greatly higher than that of Simple snoring group and Normal control group(P<0.05).There were no significant differences of pure tone auditory thresholds for each frequencies(250~8000Hz)between the Simple snoring group and Normal control group(P>0.05).There were no significant changes about pure tone auditory thresholds for each frequencies(250 ~8000Hz)after CPAP(P>0.05).2 Compared with the Simple snoring group and Normal control group,the amplitudes of DPOAEs(0.5~8 kHz)on OSAHS group were reduced significantly(P<0.05).There were no significant differences in amplitudes of DPOAEs(0.5~8 kHz)between Simple snoring group and Normal control group(P>0.05).After increased at 1kHz,2kHz,3kHz,4kHz,6kHz,8 kHz(P<0.05).3 The detection rates of DPOAEs(0.5~8 kHz)about OSAHS group were obviously declined to the other two groups(P<0.05).There were no significant differences between Simple snoring group and Normal control group(P>0.05).After CPAP,the detection rates of DPOAEs(0.5-8 k Hz)were increased,the differences were statistically significant(P<0.05).4 The peak latency of I?III?V and interpeak latency of III-V,I-V in OSAHS group patients were longer than that of the other two groups,the differences were statistically significant(P<0.05),and the differences of the interpeak latency of I-III in OSAHS did not change significantly compared with the other two groups(P>0.05).There were no significantly differences between Simple snoring group and Normal control group(P>0.05).After CPAP,the peak latency I?III?V and interpeak latency of I-III,III-V,I-V were not changed significantly(P>0.05).Conclusion:1 The auditory function of patients who were diagnosed with severe OSAHS were impaired,which could be shown in the increase of High frequency hearing threshold,the amplitudes and detection rates of DPOAE and the prolonged peak latency of I?III?V and interpeak latency of III-V,I-V.2 Treatment of CPAP can partly improve the function of the cochlea in severe OSAHS patients,which can be shown in the amplitudes and detection rates of DPOAE,which had no influence in auditory brainstem responses.As we considered,due to the long-term oxygen depletion,the changes in the structure of the brain stem is not easy to recover in a short time or it is irreversible.