A protocol for the identification and monitoring of aminoglycoside-induced cochleotoxicity : a systematic literature review

Abstract

Objective: This study aimed to examine the current available peer-reviewed evidence in order to gain insight into the most effective procedures used for the early identification and monitoring of aminoglycoside (AG)-induced cochleotoxicity and to suggest a protocol based on these findings. Method: Several databases were sourced with a comprehensive search conducted on Pubmed, Scopus and Medline (Ovid) to identify peer-reviewed studies published in English up until March 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were adhered to. Studies were subjected to pre-set inclusion and exclusion criteria in order to eliminate the possibility of effects other than AG/s influencing auditory functioning. The reference lists of the included studies were also screened. Results: Twenty-one studies met the inclusion criteria for the systematic review and were analysed. The majority of the studies used conventional pure tone audiometry (PTA) with only a few studies using extended high frequencies (EHF/s) and otoacoustic emission (OAE) testing. Conclusion: Since the damaging effect of AG/s is evident at the outer hair cells (OHC/s) of the basal end of the cochlea first, EHF audiometry and distortion product otoacoustic emissions (DPOAE/s) testing seems more promising for the early detection and monitoring of AG-induced cochleotoxicity. For effective and efficient identification and monitoring of AG-induced cochleotoxicity, a test battery comprising of a combination of subjective and objective measures, specifically aimed at the OHC/s by means of EHF audiometry and OAE-testing (DPOAE specifically) and possibly speech-in-noise (SPIN) tests such as the digits-in-noise (DIN) / SPIN-tests, is recommended as a standard protocol.