High-frequency audiometry reveals high prevalence of aminoglycoside ototoxicity in children with cystic fibrosis

TLDR

Intravenous aminoglycoside antibiotics used in cystic fibrosis are known to cause ototoxicity, yet routine audiological monitoring is uncommon and usually limited to standard pure‑tone audiometry. This study aimed to assess ototoxicity in children with cystic fibrosis, identify the most effective audiological tests, and determine risk factors. Seventy CF children (mean age 10.7 yr) were evaluated with standard PTA, extended high‑frequency audiometry, and distortion‑product otoacoustic emissions. Ototoxicity was detected in 24 % of children by EHF audiometry and DPOAE, a higher prevalence than the 13 % identified by standard PTA; the number of aminoglycoside courses, age, and lower lung function were risk factors, indicating that EHF audiometry should be the preferred screening tool.

Abstract

Intravenous aminoglycoside (IV AG) antibiotics, widely used in patients with cystic fibrosis (CF), are known to have ototoxic complications. Despite this, audiological monitoring is not commonly performed and if performed, uses only standard pure-tone audiometry (PTA). The aim of this study was to investigate ototoxicity in CF children, to determine the most appropriate audiological tests and to identify possible risk factors.Auditory assessment was performed in CF children using standard pure tone audiometry (PTA), extended high-frequency (EHF) audiometry and distortion-product otoacoustic emissions (DPOAE).70 CF children, mean (SD) age 10.7 (3.5) years, were recruited. Of the 63 children who received IV AG, 15 (24%) children had ototoxicity detected by EHF audiometry and DPOAE. Standard PTA only detected ototoxicity in 13 children. Eleven of these children had received at least 10 courses of IV AG courses. A 25 to 85 dBHL hearing loss (mean±SD: 57.5±25.7 dBHL) across all EHF frequencies and a significant drop in DPOAE amplitudes at frequencies 4 to 8 kHz were detected. However, standard PTA detected a significant hearing loss (>20 dBHL) only at 8 kHz in 5 of these 15 children and none in 2 subjects who had significantly elevated EHF thresholds. The number of courses of IV AG received, age and lower lung function were shown to be risk factors for ototoxicity.CF children who had received at least 10 courses of IV AG had a higher risk of ototoxicity. EHF audiometry identified 2 more children with ototoxicity than standard PTA and depending on facilities available, should be the test of choice for detecting ototoxicity in children with CF receiving IV AG.