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Semin Hear 2019; 40(02): 122-143
DOI: 10.1055/s-0039-1684042
Review Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Monitoring Protocols for Cochlear Toxicity

Sherman G. Lord
1   e3 Midlantic Technologies Group, Colmar, Pennsylvania
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Publication History

Publication Date:
26 April 2019 (online)

Also available atMedOne
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Abstract

The need for monitoring hearing and auditory function during drug therapy and other treatments that have the potential to cause hearing loss is well documented. Besides the main purpose of ototoxic monitoring, which is to provide feedback to the attending physician about the effects the treatment is having on the auditory system, it is also helpful in setting expectations for the patient and his/her family about the communication issues that may result from the drug therapy. This article will review tests available to an audiologist, both subjective and objective, that can be used to effectively monitor hearing levels and auditory function during treatment. Published guidelines and various ototoxic monitoring protocols are reviewed regarding tests administered, what constitutes a significant change in test results and how these findings are reported, and the impact significant changes may have on the course of treatment. Test protocols from different institutions are compared for both similarities and contrasts. Effective scheduling and test location are key to a successful monitoring program. Finally, the need to streamline ototoxic monitoring of hearing and auditory function to reduce test time and make it less stressful and tiresome on the patient will be considered.

Keywords

ototoxicity - distorting product otoacoustic emissions - extended high-frequency audiometry - ototoxic monitoring program

Highlights

• Audiologic ototoxicity monitoring is not well established and continues to be an inconsistent practice for many adult oncology and infectious disease patients.[8]

• Audiologists should take the lead in efforts to implement audiologic ototoxic monitoring programs through education of medical personnel involved in the care of patients on ototoxic medication and on the impact ototoxic hearing loss may have on a patient's quality of life.

• As the survival rate for cancer patients continues to rise, the need for early identification, serial monitoring, counseling, and possible intervention with appropriate audiologic care and treatment is critical to maintain and improve the patient's quality of life.

• Baseline testing should be conducted prior to treatment. Modification to the conventional audiologic test battery is necessary to accommodate patient needs throughout treatment.

• EHF shows evidence of change due to ototoxicity before DPOAE testing and both before standard frequency audiometry.[5]

• EHF audiometry is the most important test in the AOMP and should be administered at the baseline assessment and all subsequent monitoring tests.

• Changes in DPOAE levels precede changes in hearing levels.

• Threshold shifts in adjacent frequencies indicate more systematic change and increase the likelihood of a true decrease in hearing sensitivity.

• Any significant change in hearing thresholds must be confirmed with a repeat test within 24 hours[5] and reported to the physician and medical team immediately.

• Physicians in charge of the medication regimen may state ahead of time that any changes in hearing level during treatment will not bring about a change in the treatment plan. In that case, Campbell recommended that only the standard frequency range be tested.[23]

• Noise exposure can exacerbate the ototoxic effects of both aminoglycosides and cisplatin.[23]

• Preexisting hearing loss affecting the high frequencies negatively affects the ability to utilize EHF audiometry and DPOAE as an effective monitoring tool.[23]

• Most changes in hearing occur in the octave preceding the highest audible frequency.[6]

• The presence of preexisting hearing loss is important in identifying risks, presenting them to the patient, and setting the stage for follow-up counseling and/or rehabilitation.[45]

• Effective grading scales that report the functional impact ototoxicity has on a patient need to be included in the AOMP.

• New audiometric tools should make testing more efficient and convenient for the patient and staff.