Acoustic reflex on newborns: the influence of the 226 and 1,000 Hz probes.

PURPOSE: To analyze the occurrence of acoustic reflex and its threshold on newborns using the 226 and 1,000 Hz probes. METHODS: Thirty-six newborns with "PASS" results in newborn hearing screening and tympanogram with one or two peaks for both probe tones were included. Group I comprised 20 full-term newborns without risk indicator for hearing loss, and Group II comprised 16 newborns with at least one risk indicator. The study about ipsilateral acoustic reflex thresholds was conducted in 500, 1,000, 2,000, and 4,000 Hz. RESULTS: The groups presented the acoustic reflex thresholds between 50 and 100 dB for both probe tones. In the comparison between the probes, there were differences in all frequencies evaluated in Group I, with the lowest threshold mean for the 1,000 Hz probe. In Group II, differences were detected at 2,000 Hz. The mean acoustic reflex thresholds were similar in both groups for the 226 Hz probe. There was a difference for the 1,000 Hz probe in all tested frequencies. The percentage of response was higher in both groups for the 1,000 Hz probe. The kappa test showed extremely poor agreement in the comparison of results between both probes. CONCLUSION: The occurrence of acoustic reflex was higher in newborns and its thresholds were lower with the 1,000 Hz probe both for healthy newborns and for newborns at risk.

Acoustic reflex on newborns: the influence of the 226 and 1,000 Hz probes / A influência da sonda de 226 e 1.000 Hz no registro do reflexo acústico em neonatos

PURPOSE: To analyze the occurrence of acoustic reflex and its threshold on newborns using the 226 and 1,000 Hz probes. METHODS: Thirty-six newborns with "PASS" results in newborn hearing screening and tympanogram with one or two peaks for both probe tones were included. Group I comprised 20 full-term newborns without risk indicator for hearing loss, and Group II comprised 16 newborns with at least one risk indicator. The study about ipsilateral acoustic reflex thresholds was conducted in 500, 1,000, 2,000, and 4,000 Hz. RESULTS: The groups presented the acoustic reflex thresholds between 50 and 100 dB for both probe tones. In the comparison between the probes, there were differences in all frequencies evaluated in Group I, with the lowest threshold mean for the 1,000 Hz probe. In Group II, differences were detected at 2,000 Hz. The mean acoustic reflex thresholds were similar in both groups for the 226 Hz probe. There was a difference for the 1,000 Hz probe in all tested frequencies. The percentage of response was higher in both groups for the 1,000 Hz probe. The kappa test showed extremely poor agreement in the comparison of results between both probes. CONCLUSION: The occurrence of acoustic reflex was higher in newborns and its thresholds were lower with the 1,000 Hz probe both for healthy newborns and for newborns at risk. .

OBJETIVO: Verificar a ocorrência e o limiar do reflexo acústico em neonatos utilizando a sonda de 226 e 1.000 Hz. MÉTODOS: Trinta e seis neonatos com resultado "PASS" na triagem auditiva neonatal e timpanogramas com um ou dois picos para os dois tons de sonda. O Grupo I foi composto por 20 neonatos a termo sem indicador de risco para deficiência auditiva e o Grupo II, por 16 neonatos com pelo menos um indicador de risco. A pesquisa dos limiares do reflexo acústico ipsilateral foi realizada em 500, 1.000, 2.000 e 4.000 Hz. RESULTADOS: Os grupos apresentaram limiar do reflexo acústico entre 50 e 100 dB para ambos os tons de sonda. Na comparação entre as sondas, houve diferença em todas as frequências avaliadas no Grupo I, com a média de limiares menor com a sonda de 1.000 Hz. No Grupo II, foi detectada diferença em 2.000 Hz. Com a sonda de 226 Hz, os limiares médios do reflexo acústico foram semelhantes nos dois grupos. Com a sonda de 1.000 Hz, houve diferença em todas as frequências avaliadas. A porcentagem de presença de resposta foi maior para ambos os grupos para a sonda de 1.000 Hz. O teste kappa revelou concordância extremamente pobre na comparação dos resultados entre as duas sondas. CONCLUSÃO: A ocorrência de reflexo acústico em neonatos foi maior e os limiares menores com a utilização da sonda de 1.000 Hz, tanto para neonatos saudáveis como para os neonatos de risco. .

Reflectometría acústica: un método objetivo para el estudio de efusión en el oído medio / Acoustic reflectometry: an objective method for the study of middle ear effusion

La efusión el oído medio es una de las patologías más frecuentes en pediatría, y requiere para su diagnóstico la confirmación de líquido en el oído. La timpanometría es el método objetivo más usado para confirmar efusión en el oído medio cuando la otoscopía es dudosa o alterada. La reflectometría acústica es un nuevo método que ofrece las ventajas de ser portátil, indoloro y de fácil manejo. Se estudiaron 104 niños entre seis meses y 18 años, a los que se les realizó timpanometría y reflectometría acústica con un total de 204 oídos evaluados, considerando como riesgo de efusión en el oído medio valores de ángulo de gradiente espectral entre 0 y 64º. Al comparar la reflectometría con la timpanometría (prueba estándar) se observó una especificidad de 99 por ciento, una sensibilidad de 57 por ciento, un valor predictivo positivo de 97 por ciento y un valor predictivo negativo de 75 por ciento. Estos resultados nos permiten recomendar a la reflectometría acústica como método objetivo para descartar con alta seguridad la presencia de líquido en el oído medio. Por sus ventajas sugerimos su implementación y utilización masiva en la población pediátrica, lo que ayudaría a un manejo más expedito y adecuado de la otitis media secretora.

Impedanciometría como examen auxiliar para el diagnóstico topográfico de las hipoacusias en el Servicio de O.R.L. del Hospital Regional Honorio Delgado, 1993 - 1995 Arequipa

El presente fue un estudio de tipo retrospectivo, descriptivo, transversal, el cual se realizó con el objetivo de determinar la utilidad de la Impedanciometría para el diagnóstico topográfico de las hipoacusias para lo cual se consideraron a 90 pacientes de ambos sexos, que consultaron al Servicio de Otorrinolaringología del Hospital Regional Honorio Delgado, durante los años 1993 - 1995, que contaron con estudios impedanciométricos. En cuanto a los resultados obtenidos, se logró determinar que la hipoacusia y los acúfenos fueron los síntomas predominantes en la mayoria de los pacientes, la obstrucción nasal en frecuencia importante, siendo la adenoiditis hipertrófica la patología asociada más frecuentemente encontrada, y al realizar el examen físico se encontró que casi la mitad de oídos eran normales. Así mismo se recoleccionó los diagnósticos audiométricos y los resultados impedanciométricos, determinando la topografía de la hipoacucias a la utilidad de la Impedanciometría como examen auxiliar. En conclusión se logró demostrarla determinación de los diagnósticos topográficos de hipoacusias, además demostró la gran utilidad en pacientes en que por alguna circunstancia no se les pudo hacer audiometría. Esto se debe a que la Impedanciometría es un examen objetivo, no así la audiometría que es un examen subjetivo.

Detection of middle ear effusion by acoustic reflectometry.

Existing diagnostic methods for otitis media with effusion are inadequate. We designed, built, and tested an acoustic reflectometer to overcome such inadequacies. The probe is placed at the entrance to the external auditory canal, whereupon a swept tone (1800 to 7000 Hz) is generated. The device records sound amplitude representing the sum of incident and reflected sound. This sum reaches a nadir at a frequency for which the quarter wave length corresponds to the distance from the microphone to the tympanic membrane; at this frequency reflected sound is maximally out of phase with incident sound. We measured this nadir (in decibels) and correlated the decrease in sound level at the nadir with the presence or absence of middle ear effusion. With a diagnosis confirmed by acoustic admittance and pneumatic otoscopy (n = 290), and using a breakpoint of 4.0 dB, the sensitivity was 94.4% and the specificity was 79.2%. Acoustic reflectometry can be portable, results are virtually instantaneous, and the method is reliable independent of age, crying, cerumen, and lack of cooperation from the child.