Distortion product otoacoustic emission in newborn exposed to ototoxic / "Emissões otoacústicas produto de distorção em recém-nascidos medicados com ototóxicos"

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The amynoglicosides are frequently used in nurseries and may be toxic for the cochleo-vestibular hair cells, specially for the outer cells of the cochlear base. The distortion product otoacoustic emissions allow to evaluate specific portions of the cochlea even before the hearing sensation is altered, and are ideal for the early analysis of this auditory structure integrity, besides being indicated for newborns once they are objective. The aim of this prospective longitudinal study is to research the amplitude of distortion product otoacoustic emissions caused by the ototoxic drugs use, between the end of the administration and from 15 to 40 days after its use. The population studied was composed by term and preterm newborns from a nursery and maternity of a Santo André city hospital, in the period from July 2003 to September 2004. The first evaluation occurred on the hospital discharge day. Three groups were evaluated: control group with 33 term and healthy newborns; term study group with 19 term newborns with more than 37 weeks exposed to amicacin and/or vancomycin; and preterm study group with 15 preterm newborns from 32 to 37 weeks exposed to the same ototoxic. The newborns did not present risk factors for hearing loss according to the JCIH, 2000 concomitant to the neonatal infection. All newborns were evaluated at a corrected gestational age greater than 37 weeks. The otoacoustic emissions amplitudes obtained at the hospital discharge were compared to the ones obtained from 15 to 40 days after the discharge. The results showed that the otoacoustic emissions amplitudes of the preterm study group were smaller than the amplitudes of the control group and the term study group in both moments of the test. The amplitude of the newborns’ otoacoustic emissions increased in the second moment of the test. The amplitudes were higher in the frequency of 6.000Hz and, in the right ear in the frequency f2 3.000 Hz. The otoacoustic emissions amplitudes of the control group in the second moment of the test were similar to the term study group in the first moment of the research. It was concluded that there is an increase of the distortion product otoacoustic emissions amplitude from the discharge moment until 15 to 40 days after, suggesting a maturation of the cochlear structures in the post-natal period, and that the exposure to amicacin and vancomycin on the recommended dose by Neofax®, 2003/2004 did not alter the amplitude of the emissions in the newborns without risk indicators concomitant with neonatal infection.

ASSUNTO(S)

fatores de risco vancomycin/adverse effects risk factors amikacin/adverse effects vancomycin/administration &dosage cóclea vancomicina/efeitos adversos vancomicina/administração &dosagem amicacina/administração &dosagem emissões otoacústicas espontâneas hearing loss infant newborn amikacin/administration &dosage otoacoustic emissions spontaneous perda auditiva amicacina/efeitos adversos cochlea recém-nascido

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