[The influence of haemodialysis on hearing organ of children with chronic renal failure].

Haemodialysis applied in terminal phase of chronic renal failure causes considerable metabolic and electrolyte disturbances within a few hours in human organism. The aim of the work was an evaluation of the influence of those disturbances on hearing organ as potential factors being responsible for perceptive hearing loss in considerable number of the patients with chronic renal failure (CRF). Examination was conducted on 20 children with CRF, aged 10-18 years. In each case, before and after dialysis, on the same day, ENT examination, pure tone audiometry, brain auditory evoked potentials (BAEP) and acoustic otoemissions (TEOAE, DPOAE) were performed. Audiometric tests revealed significantly worse hearing in children with CRF in comparison to healthy subjects with not statistically significant improvement after dialysis. Significantly elongated I, III, V peak latencies as well as I-III and I-V interpeak latencies in BAEP of children with CRF before dialysis were considerable shorter after dialysis except III-V but in 2 of them they appeared after dialysis. In 8 CRF cases DPOAE was present after dialysis in the range of frequencies absent before and in 9 CRF cases there was an increase of the response on the level of 10-15 dB for some frequencies. There were no any changes after dialysis in 3 cases with CRF. The results of our studies reflect subclinical disturbances in neural conduction of auditory pathway and its significant improvement after normalisation of blood parameters (uremic toxins, hyperkalaemia). This fact suggests central component of ureic axonopathy in the pathogenesis of hearing impairment in children with CRF. Dynamism of the changes in TEOAE and DPOAE reflects also the influence of those disturbances on auditory cells on the level of the labyrinth.