Revista de otorrinolaringología y cirugía de cabeza y cuello
versión On-line ISSN 0718-4816
TORRENTE A, Mariela; RETAMAL M, Javiera y NUNEZ T, Marcia. Hearing assesment in extremely low birth weight infants. Rev. Otorrinolaringol. Cir. Cabeza Cuello [online]. 2007, vol.67, n.2, pp. 115-121. ISSN 0718-4816. doi: 10.4067/S0718-48162007000200004.
Introduction.Very low birth weight newborns (ELBW) may present with different sensory deficiencies as a result of perinatal pathologies characteristic to this group; among them, sensorineural hearing loss (SNHL). Aims.The aim of the present study was to establish the prevalence of sensorineural hearing loss in ELBW (birth weight of less than 1500g) infants in a public hospital. Materials and Methods.Premature infants born with a birth weight < 1500 g, born at the Hospital San Juan de Dios (Santiago, Chile) between January 1st 1999 and December 31st 2004 were included. All patients were evaluated by auditory brainstem response, recording the hearing threshold, wave I and V latencies, and l-V interval. A normal threshold was defined as less or equal to 40 dB hearing level. Results.147 patients were evaluated, with a gestational age of 30 +- 2 weeks and a birth weight of 1235 +-254 g. Ofthese, 113 had a normal ABR threshold (76.9%), withawavel latency of 1.78 +- 0.21, wave V latency of 6.37 +- 0.29, l-V interval 4.55 +- 0.26. Sixteen patients hada bilateral threshold higher than 40 dB (11 %). Of these patients, six had bilateral threshold elevation with an increase in l-V interval, suggesting central hearing impairment. Conclusion.In the population of premature infants evaluated, the prevalence of bilateral SNHL was 4%.
Palabras clave : Hearing loss; low birth weight infant; premature; auditory screening.