Newborn hearing screening in the NICU: profile of failed auditory brainstem response/passed otoacoustic emission

OBJECTIVE: Incidence of a specific pattern of auditory responses, absent auditory brainstem responses (ABRs) and present otoacoustic emissions (OAEs), in newborn hearing screening in a regional perinatal center neonatal intensive care unit (NICU) is described. This profile, labeled auditory neuropathy or auditory dyssynchrony (AN/AD), is a dysfunction in neural/brainstem transmission that occurs in individuals whose outer hairs cells are functioning normally. Although the AN/AD profile has been associated with various risk factors, incidence and prediction are unknown.

METHOD: Analysis of electrophysiologic measures and medical record reviews of the first 22 months of the universal newborn hearing-screening program was conducted. Association of the AN/AD profile was evaluated with the following factors: gender, gestational age, ototoxic drug regimen, low birth weight, hyperbilirubinemia, hydrocephalus, low Apgar score, anoxia, respiratory distress syndrome, pulmonary hypertension, intraventricular hemorrhage, multiple birth, seizure activity, and family history.

RESULTS: One hundred fifteen (24.1%) of the 477 infants failed the ABR in 1 or both ears and passed OAEs bilaterally. Comparisons of infants fitting the AN/AD profile with those not fitting the AN/AD profile were negative with 3 exceptions: those with hyperbilirubinemia and those who were administered vancomycin or furosemide. A logistic-regression analysis model failed to predict which infants would be at risk for the AN/AD profile either unilaterally or bilaterally.

CONCLUSIONS: Screening of NICU infants should be conducted with ABR first, followed by OAE after failure on ABR. Because the incidence of the AN/AD profile was found to be 24% in this at-risk population, additional study is warranted.