Assessment of aminoglycoside-induced hearing impairment in hospitalized neonates by TEOAE

Abstract
Aminoglycosides, as potent bactericidal antibiotics against aerobic gram-negative infections, is still widely used, especially in NICU patients, despite their known potential ototoxic effects. To evaluate the potential of transient evoked otoacoustic emissions (TEOAEs) in early identification of decreased hearing sensitivity in hospitalized neonates receiving aminoglycosides for severe gram-negative infections. Fifty (50) neonates treated with intravenous gentamicin (5 mg/kg/day) or amikacin (15 mg/kg/day) were tested with TEOAE in the beginning and the end of aminoglycoside therapeutic course. There were 23 males and 27 females, ranging from 29 to 40 weeks (mean: 36 weeks). The treatment duration was 3–30 days (in 26 neonates up to 7 days — group A, and in 24 neonates higher than 7 days — group B). In group A, no statistically significant difference in the mean response level was found between the onset and the end of treatment course (p > 0.001). In group B, a statistically significant difference in the mean response level was found between the onset and the end of treatment course, especially at high frequency region (p < 0.001). TEOAE is sensitive enough to detect early aminoglycoside ototoxicity. As this test is simple to perform, non-invasive and reliable, so we suggest that TEOAE test should be performed in NICU as routine for monitoring cochlear function to prevent permanent hearing loss especially in those who are receiving aminoglycoside for more than 7 days.