Analysis of transient otoacoustic emissions and brainstem evoked auditory potentials in neonates with hyperbilirubinemia

Hearing and neurological impairment in children with history of exchange transfusion for neonatal hyperbilirubinemia

The objective was to determine frequency of sensorineural hearing loss (SNHL), identified by abnormal threshold in evoked potentials, absence of otoacoustic emissions and behavioral responses, auditory neuropathy (AN) (absence of evoked potentials, with preservation of otoacoustic emissions), and neurological comorbidity in infants with hyperbilirubinemia (HB) treated with exchange-transfusion (ET). From a total of 7,219 infants, ET was performed on 336 (4.6%). Inclusion criteria were fulfilled in 102; 234 children did not meet criteria (182 outside of the study period, 34 did not have complete audiological evaluation, and 18 rejected the followup). Thirty-five children (34%) were born at-term and 67 (66%) were preterm. Children had a mean age of 5.5 ± 3.9 years. Main causes of ET were Rh isoimmunization in 48 (47%), ABO incompatibility in 28 (27.5%), and multifactorial causes in 26 (25.5%). Fifteen (15%) children presented with SNHL. Preterm newborns presented more often with SNHL. Indirect bilirubin level was higher in children with SNHL (22.2 versus 18.7 mg/dL, P = 0.02). No cases of AN were documented. An increased risk of neurologic sequelae was observed in children with SNHL. In conclusion, we disclosed a high frequency of SNHL in children with neonatal HB and ET and neurological alterations. No cases of AN were observed.

Neonatal Hearing Screening: failures, hearing loss and risk indicators

To check the rate of failure, hearing loss and its association with demographic variables and risk indicators for hearing loss in newborns submitted to the Newborn Hearing Screening in a secondary hospital.

MATERIALS AND METHODS

Cross-sectional and retrospective study, involving 1,570 newborns submitted to the different stages of the Newborn Hearing Screening Program. Initially, we carried out otoacoustic emission tests (ILO Echocheck) and the cochlear-eyelid reflex. Afterwards, we analyzed the demographic and clinical characteristics of the newborns, screening rate of failure, hearing loss and its association with demographic variables and risk indicators.

RESULTS

Twenty-six newborns had failures in the first stages of the Program (1.7%), who were then referred to diagnostic evaluation. Of these, 16 (61.5%) did not come, two (7.7%) had normal results and eight (30.8%) were diagnosed with hearing disorders. The screening failure rate was 1.7% and the frequency of hearing disorders was 0.5%.

CONCLUSIONS

Pre-term newborns of very low birth weights had higher rates of screening failures and a greater occurrence of hearing changes. The factors associated with screening failure and hearing changes were similar to the ones described in the literature.