Hearing evaluation with distortion-product otoacoustic emissions in young patients undergoing haemodialysis

Sensorineural hearing loss is frequently reported in young patients with ch ronic renal failure having haemodialysis. The effect of a single session of haemodialysis on hearing acuity was assessed prospectively in nine childre n with end-stage renal disease using pure-tone audiometry (PTA) and distort ion-product otoacoustic emissions (DPOAEs). Results were compared with thos e obtained from nine audiologically normal healthy children also tested wit h PTA and DPOAEs twice during a 4-h interval. Sensorineural hearing loss of unknown aetiology was found in 55.5% of renal patients, mainly in the high er frequencies. Patients on HD had mean PTA thresholds significantly poorer than those of the control group in the frequency range 1000-12000Hz (P < 0 .05). Their mean DPOAE amplitudes were significantly lower in all frequenci es > 1184 Hz (P < 0.05), Furthermore, patients' ears with normal PTA thresh olds between 250 and 4000 Hz also had decreased DPOAE amplitudes. No signif icant changes in PTA thresholds or DPOAE amplitudes were encountered in ren al patients before and after a HD session (P > 0.05). Changes in PTA thresh olds or DPOAE amplitudes were not significantly different than those in the control group (P > 0.05). In conclusion, sensorineural hearing loss of unk nown origin, especially in high frequencies, is frequent in young renal pat ients under HD and single HD sessions do not seem to alter the hearing acui ty of these patients. DPOAEs seem to be more sensitive to incipient cochlea r damage than behaviour thresholds in monitoring renal patients.