Screening sluchu u novorozenců pomocí tranzientně evokovanych otoakustických emisí

Objective: Behavioral audiometry is currently accepted as the universal neonatal hearing examination in the Czech Republic. Only in some regional hospitals screening for hearing impairment is done using otoacoustic emissions, exclusively aimed at high-risk neonates. This study summarizes the three years experience with regular transient evoked otoacoustic emissions (TEOAE) screening in neonates. Study design: The prospective study enrolled all neonates (inborn or outborn) admitted to the Dept. of Neonatology in 1997 - 1999. TEOAE screening was performed in 4790 neonates. The neonates were divided into two groups according to risk factors for hearing impairment (risk positive group n = 399, risk negative group n = 4391). Full-term healthy neonates were screened at the age of 2 - 4 days and preterm infants at the 40th postconceptional week. First and second repeated tests were done in 4-week intervals. Babies in whom reliable TEOAE were not recorded in the second repeated test were subsequently examined by auditory brainstem responses (ABR). Results: Prevalence of hearing loss in our study was 1 in 384 (261 in 100,000) in the risk-negative group and 1 in 27 (3652 in 100,000) in risk positive newborns. Specificity in the risk-negative group was 0.92, resp. 0.8 in the risk-positive group. Positive predictive value of the screening was 0.03, resp. 0.17 in the risk group. Hearing impairment of different magnitude was verified by ABR in 6 babies in each group. Conclusion: There is evidence from population-based surveys that diagnosis and treatment are delayed until age 1 or 2 years in many children with hearing impairment. TEOAE and ABR are technically highly accurate screening tests for hearing impairment in newborns. Using these screening methods is essential for early identification of hearing impairment and for further development of such infants, as well as for further family planning in the affected families.