Proposed comprehensive ototoxicity monitoring program for VA healthcare (COMP-VA)

The use of tele-audiology in ototoxicity monitoring: A scoping review

INTRODUCTION

Due to the growing burden of disease in South Africa, encompassing conditions such as tuberculosis, human immunodeficiency virus, and cancer, the holistic management of affected patients incorporating ototoxicity monitoring is a necessity. However, ototoxicity monitoring in developing countries may be limited due to a lack of resources and inadequate healthcare facilities. Subsequently, the use of tele-audiology may be a revolutionary technique with the potential to provide audiology services to under-served populations with limited access.

METHODS

The study aimed to describe the use of tele-audiology services in ototoxicity monitoring through a scoping review of English peer-reviewed articles from June 2009 to June 2020. Seventeen articles were purposively selected from the following databases: PubMed, Science Direct, Taylor and Francis Online, WorldCat, and Google Scholar. Data was extracted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses diagram and results were analyzed using deductive thematic analysis.

RESULTS AND DISCUSSION

While a minority of the studies indicated that the cost of implementation and network connectivity within a South African context pose as barriers, most researchers reported that tele-audiology provides a reliable, time-efficient, cost-effective, and easily accessible alternative for ototoxicity monitoring. Hardware including the WAHTS, KUDUwave, and OtoID, along with software such as the TabSINT, Otocalc, uHear, and the hearTest, have proven to be useful for ototoxicity monitoring. A need for further investigations regarding the feasibility of tele-audiology implementation in South Africa is evident. Despite this, it provides audiologists with an opportunity to offer contact-less services during COVID-19, thus, confirming its versatility as an augmentative method for ototoxicity monitoring.

Clinical Observations in Patients With Cystic Fibrosis-Related Diabetes and Self-Reported Ototoxicity Symptoms

PURPOSE

Persons with cystic fibrosis (PwCF) are at high risk for ototoxicity due to the routine use of intravenous aminoglycoside (IV-AG) antibiotics in respiratory infection management. Additionally, factors that contribute to ototoxicity-related symptom development and severity in PwCF are unknown. Given the increased risk of ototoxicity in people with diabetes, we explored the association between cystic fibrosis-related diabetes (CFRD) and self-reported ototoxicity symptoms (tinnitus and vestibular problems) in PwCF treated with aminoglycosides.

METHOD

PwCF (N = 39; 25 females, 14 males; Mage = 30.1 years, SD = 10.3) were recruited from the Cystic Fibrosis Care Center at Oregon Health & Science University. Patients completed the validated questionnaires to ascertain their experiences with ototoxicity-related symptoms of tinnitus and balance function. The diagnosis of CFRD, including oral glucose tolerance testing (OGTT), insulin treatment, hemoglobin A1c, and cumulative IV-AG treatment history, was obtained through a medical chart review. Participants were classified into three groups based on their medical diagnoses via OGTT: normal glucose tolerance (NGT; control; n = 16), abnormal glucose tolerance (AGT; n = 9), and CFRD (n = 14). Participants in each group were further classified based on survey outcomes for ototoxicity-related symptoms.

RESULTS

There was a trend toward a higher proportion of patients with CFRD reporting tinnitus compared to the AGT and NGT groups, but did not meet statistical significance (X2 = 2.24, p = .13). Approximately, 43% of patients with CFRD reported experiencing clinically significant tinnitus lasting > 3 min compared to 11% in the AGT group and 13% in the NGT group (X2 = 3.751, p = .05). Cumulative IV-AG exposure tended to be higher in CFRD compared to other groups. High balance function was generally reported in all groups.

CONCLUSIONS

Patients with CFRD have greater ototoxicity-related symptoms. Further investigation of the relationship between CF-related comorbidities and the risk of developing ototoxicity-related symptoms is warranted to improve the detection and management of ototoxicity in PwCF.

Cisplatin-Induced Ototoxicity: A Concise Review of the Burden, Prevention, and Interception Strategies

Cisplatin is a bedrock of cancer management and one of the most used chemotherapeutic agents in the treatment of germ cell, lung, bladder, ovarian, and head and neck cancers. Approximately 500,000 patients diagnosed annually with these cancer types in the United States could be candidates for treatment with cisplatin. There is a 5-fold increase in the risk of hearing impairment or ototoxicity with cisplatin, which can manifest as ringing in the ear (tinnitus), high-frequency hearing loss, and at late stages, a decreased ability to hear normal conversation. More than half of adult and pediatric patients with cancer treated with cisplatin developed hearing impairment with major impact on patients' health-related quality of life. A considerable evidence gap persists regarding the burden and effective prevention and interception strategies for cisplatin-induced ototoxicity, especially in adult patients with cancer. We conducted a review of the published literature to provide an update on the status of this important clinical challenge. We also surveyed practicing oncologists within our network of academic and community practices to gain a better understanding of how the published literature compares with real-world practice. Our review of the literature showed a lack of standardized guidelines for monitoring and treatment of cisplatin-induced ototoxicity, especially in the adult cancer patient population. Our survey of practicing oncologists mirrored the findings from the published literature with a heterogeneity of practice, which highlights the need for standardization.

Cisplatin-associated ototoxicity: perspectives from a single institution cervical cancer cohort and implications for developing a locally responsive monitoring programme in a public healthcare setting

Background

Ototoxicity monitoring is uncommon in South Africa, despite the increased use of ototoxic medication to manage the burden of disease in the country. The successful implementation of such a protocol requires cognisance of contextual realities and multiple dimensions for consideration from both patients and service providers. As part of an ongoing cohort study on cisplatin-associated ototoxicity and efforts to better inform the implementation of such programmes, the perspectives of cervical cancer patients and healthcare workers towards ototoxicity monitoring were assessed.

Methods

This concurrent-triangulation mixed-methods study was conducted at a tertiary hospital in South Africa. Self-reported questionnaires from patients (n = 80) and healthcare personnel comprising clinicians, oncology nurses, pharmacists, and radiotherapists (n = 32), results of audiological evaluations, researcher field notes, and estimated patient and service provider costs contributed to data for this study. Data analysis included descriptive statistics, comparison of test characteristics and deductive thematic analysis.

Results

The ototoxicity monitoring programme was positively received by the participants, with 90.6% of healthcare personnel and 89% of patients reporting it to be beneficial. The clinicians (76.6%) were identified as the main providers of information on the effects of chemotherapy medication and made the necessary referrals for audiological evaluation. The approximate cost of setting up such a programme included purchase of equipment (US56 700) and the appointment of an audiologist (US 26 250). The approximate costs to patients included transport costs (US$ 38) and the loss of income for the day (US 60), calculated at the minimum wage per hour, if employed. Creative appointment scheduling, easy facility access and detailed locally comprehensible couselling improved patient compliance to the programme. Whilst the sequential use of American Speech-Language-Hearing Association (ASHA) and National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) criteria aided in an evidence-informed approach to aural rehabilitation, DPOAEs and speech discrimination displayed low sensitivity (range 1.45% – 22.39%) but high specificity (range 77.78% – 100%) when identifying ototoxic change.

Conclusion

This novel study, through a ‘real-world’ experience, has revealed that an ototoxicity monitoring programme is feasible in South Africa, through meaningful engagements with- and considerations from- patients and service providers regarding planning, delineation of responsibilities and cost implications. The findings can potentially serve as a roadmap for other limited resource environments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08099-8.

Association of hearing loss and tinnitus symptoms with health-related quality of life among long-term oropharyngeal cancer survivors

BACKGROUND

This study investigated the association of hearing loss and tinnitus with overall health-related quality of life (HRQoL) among long-term oropharyngeal cancer (OPC) survivors.

METHODS

This study included OPC survivors treated between 2000 and 2013 and surveyed from September 2015 to July 2016. Hearing loss and tinnitus were measured by asking survivors to rate their "difficulty with hearing loss and/or ringing in the ears" from 0 (not present) to 10 (as bad as you can imagine). Hearing loss and tinnitus scores were categorized as follows: 0 for none, 1-4 for mild, and 5-10 for moderate to severe. The primary outcome was the mean score of MD nderson Symptom Inventory Head & Neck module interference component as a HRQoL surrogate dichotomized as follows: 0 to 4 for none to mild and 5 to 10 for moderate to severe interference.

RESULTS

Among 880 OPC survivors, 35.6% (314), reported none, 39.3% (347) reported mild, and 25.1% (221) reported moderate to severe hearing loss and tinnitus. On multivariable analysis, mild (OR, 5.83; 95% CI; 1.48-22.88; p = 0.012) and moderate (OR, 30.01; 95% CI; 7.96-113.10; p < 0.001) hearing loss and tinnitus were associated with higher odds of reporting moderate to severe symptom interference scores in comparison to no hearing loss and tinnitus. This association of hearing dysfunction was consistent with all domains of HRQoL.

CONCLUSIONS

Our findings provide preliminary evidence to support the need for continued audiological evaluations and surveillance to detect hearing dysfunction, to allow for early management and to alleviate the long-term impact on QoL.

Hearing and Vestibular Loss with Misuse of Opioids and Illicit Drugs: A Review of the Literature

BACKGROUND

The purpose of this review was to summarize the literature regarding the effects of opioids and illicit drugs on the auditory and vestibular systems.

METHODS

Data were sourced from published papers reporting hearing loss (HL) and/or vestibular loss (VL) following misuse or overdose of opioids or illicit drugs. Most papers consisted of retrospective single-case reports, with few retrospective reviews or prospective cohort studies. Search terms included variations of HL, VL, opioids, and illicit drugs. Search results yielded 51 articles published between 1976 and 2021. A total of 44 articles were reviewed after excluding studies that were not available in English (n = 3), only described acute effects in healthy cohorts (n = 3) or only described general health aspects in a group on methadone maintenance (n = 1).

RESULTS

Sixteen studies reported ototoxicity from illicit drugs, 27 from prescription opioids, and 1 was unspecified. This review shows that HL associated with amphetamines and cocaine was typically sudden, bilateral, and temporary. HL from cocaine/crack and heroin often presented with greatest losses in the mid-frequency range. HL associated with opioids was typically sudden, bilateral, moderately severe to profound, and in most cases permanent. The literature is sparse regarding VL from illicit drugs and opioids.

CONCLUSION

Practitioners who see patients for sudden or rapidly progressive HL or VL with no apparent cause should inquire about misuse of illicit drugs and opioids, particularly when the HL does not respond to steroid treatment.

Mechanisms of Aminoglycoside- and Cisplatin-Induced Ototoxicity

Purpose This review article summarizes our current understanding of the mechanisms underlying acquired hearing loss from hospital-prescribed medications that affects as many as 1 million people each year in Western Europe and North America. Yet, there are currently no federally approved drugs to prevent or treat the debilitating and permanent hearing loss caused by the life-saving platinum-based anticancer drugs or the bactericidal aminoglycoside antibiotics. Hearing loss has long-term impacts on quality-of-life measures, especially in young children and older adults. This review article also highlights some of the current knowledge gaps regarding iatrogenic causes of hearing loss. Conclusion Further research is urgently needed to further refine clinical practice and better ameliorate iatrogenic drug-induced hearing loss.

A Randomized Controlled Trial Using Automated Technology for Improving Ototoxicity Monitoring in VA Oncology Patients

Purpose Determine the efficacy of ototoxicity monitoring (OM) administered as automated protocols with the Oto-ID mobile audiometer (automated ototoxicity monitoring [A-OM]), compared with usual care (UC) OM in cancer patients receiving cisplatin. Method Participants were patients (n = 46, mean age 64.7 years; range: 30-78 years) receiving cisplatin-based chemotherapy at the Department of Veterans Affairs Portland Health Care System. A randomized controlled trial contrasted A-OM and UC at up to three program evaluations (PEs) conducted by the study audiologist who was blinded to arm through PE1. PE1 occurred before randomization or oncology treatment; PE2 and PE3 occurred during and/or after treatment at 35 and 365 days postrandomization. The A-OM group (n = 24) used Oto-ID to screen their hearing before each cisplatin dose. Oto-ID results were sent to the study audiologist for interpretation, follow-up, and care coordination. The UC group (n = 22) received a consult for OM services through the audiology clinic. Outcomes included hearing shift near each patient's high-frequency hearing limit, revised hearing-handicap inventory score, and survival time from the start of treatment. Adherence to OM protocols, patients' use of aural rehabilitation services, and oncologists' treatment decisions were also examined. Results Ototoxicity was identified at a high overall rate (46% and 76% at 35 and 365 days, respectively, postrandomization). Adherence to monitoring prior to each cisplatin dose was 83.3% for those randomized to A-OM compared with 4.5% for UC. Randomization to A-OM was not associated with reduced ototoxic hearing shifts or self-reported hearing handicap relative to UC; neither did it compromise participants' survival. Half of participants in each arm accessed aural rehabilitation services. One in each arm had a documented ototoxicity-related cisplatin dose reduction. Conclusions Auditory impairment was an actionable concern for the participants and their oncology providers. A dedicated surveillance program using the Oto-ID's automated protocols improved adherence to OM recommendations over a traditional UC service delivery model. Supplemental Material https://doi.org/10.23641/asha.16649602.

The Ototoxicity of Antimalarial Drugs-A State of the Art Review

This review summarizes current knowledge about the occurrence of hearing and balance disorders after antimalarial drugs treatment. It also examines the clinical applications of antimalarials, their mechanisms behind this ototoxicity and how it can be monitored. It includes studies with larger numbers of patients and those in which auditory function was assessed using audiological tests. Some antimalarials have been repurposed for other conditions like autoimmune disorders, rheumatic diseases, some viral diseases and cancers. While old antimalarial drugs, such as quinoline derivatives, are known to demonstrate ototoxicity, a number of new synthetic antimalarial agents particularly artemisinin derivatives, demonstrate unknown ototoxicity. Adverse audiovestibular effects vary depending on the medication itself, its dose and route of administration, as well as the drug combination, treated disease and individual predispositions of the patient. Dizziness was commonly reported, while vestibular symptoms, hearing loss and tinnitus were observed much less frequently, and most of these symptoms were reversible. As early identification of ototoxic hearing loss is critical to introducing possible alternative treatments with less ototoxic medications, therefore monitoring systems of those drugs ototoxic side effects are much needed.

A scoping review to identify strategies that work to prevent four important occupational diseases

BACKGROUND

Despite being largely preventable, many occupational diseases continue to be highly prevalent and extremely costly. Effective strategies are required to reduce their human, economic, and social impacts.

METHODS

To better understand which approaches are most likely to lead to progress in preventing noise-related hearing loss, occupational contact dermatitis, occupational cancers, and occupational asthma, we undertook a scoping review and consulted with a number of key informants.

RESULTS

We examined a total of 404 articles and found that various types of interventions are reported to contribute to occupational disease prevention but each has its limitations and each is often insufficient on its own. Our principal findings included: legislation and regulations can be an effective means of primary prevention, but their impact depends on both the nature of the regulations and the degree of enforcement; measures across the hierarchy of controls can reduce the risk of some of these diseases and reduce exposures; monitoring, surveillance, and screening are effective prevention tools and for evaluating the impact of legislative/policy change; the effect of education and training is context-dependent and influenced by the manner of delivery; and, multifaceted interventions are often more effective than ones consisting of a single activity.

CONCLUSIONS

This scoping review identifies occupational disease prevention strategies worthy of further exploration by decisionmakers and stakeholders and of future systematic evaluation by researchers. It also identified important gaps, including a lack of studies of precarious workers and the need for more studies that rigorously evaluate the effectiveness of interventions.

An Ototoxicity Grading System Within a Mobile App (OtoCalc) for a Resource-Limited Setting to Guide Grading and Management of Drug-Induced Hearing Loss in Patients With Drug-Resistant Tuberculosis: Prospective, Cross-Sectional Case Series

BACKGROUND

Tuberculosis (TB) affects millions of people worldwide and is treated with medication including aminoglycosides and polypeptides. Individuals respond differently to medications as a result of their genetic inheritance. These differences in genetic inheritance can result in the underdosing or overdosing of medication, which may affect the efficacy or, in the case of aminoglycosides and polypeptides used in the treatment of all forms of TB, result in ototoxicity. When ototoxicity is detected, physicians should adjust dosages to minimize further ototoxicity and hearing loss; however, there are no suitable grading systems to define significant hearing loss.

OBJECTIVE

The aim of this study was to develop a standardized grading system by making use of an electronic health (eHealth) platform to ensure that a user-friendly method was available to interpret hearing test results, calculate significant hearing loss, and provide recommendations with regard to dosage adjustments and management. It further aimed to establish the sensitivity of the newly developed grading scale.

METHODS

This grading system was developed in South Africa based on data that were obtained from an audiology and pharmacokinetic study on patients with drug-resistant TB (DR-TB) at two DR-TB units at state-run hospitals. This feasibility study employed a prospective, cross-sectional, exploratory, descriptive case series research design, with a total of 22 participants. Participants underwent audiological and pharmacological assessments at baseline and every 2 weeks for the first 3 months of treatment. Various professionals (8 in total) were subsequently involved in the development of the eHealth system, including a software engineer, four audiologists, a pharmacist, a medical doctor, and a nurse. The app underwent 14 modifications that involved aspects of data storage, ease of usability, grades, and the risk factor checklist.

RESULTS

An ototoxicity grading system within a mobile app for use by doctors, nurses, and audiologists was developed for patients with DR-TB. The purpose of this user-friendly ototoxicity calculator, OtoCalc, is to (1) assist health professionals in assessing patients for ototoxicity, (2) establish the clinical significance of ototoxicity by calculating the grade of hearing loss, (3) monitor the progression of hearing loss, and (4) enable systematic referral and management of patients according to their needs.

CONCLUSIONS

This newly developed system is more sensitive than the existing grading methods for determining ototoxicity in patients with DR-TB. This app needs to be trialed in a larger sample to establish data security, ease of use, and suitability within this population.

Monitoring Protocols for Cochlear Toxicity

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.

Chirp-Evoked Otoacoustic Emissions and Middle Ear Absorbance for Monitoring Ototoxicity in Cystic Fibrosis Patients

OBJECTIVES

The goal of this study was to investigate the use of transient-evoked otoacoustic emissions (TEOAEs) and middle ear absorbance measurements to monitor auditory function in patients with cystic fibrosis (CF) receiving ototoxic medications. TEOAEs were elicited with a chirp stimulus using an extended bandwidth (0.71 to 8 kHz) to measure cochlear function at higher frequencies than traditional TEOAEs. Absorbance over a wide bandwidth (0.25 to 8 kHz) provides information on middle ear function. The combination of these time-efficient measurements has the potential to identify early signs of ototoxic hearing loss.

DESIGN

A longitudinal study design was used to monitor the hearing of 91 patients with CF (median age = 25 years; age range = 15 to 63 years) who received known ototoxic medications (e.g., tobramycin) to prevent or treat bacterial lung infections. Results were compared to 37 normally hearing young adults (median age = 32.5 years; age range = 18 to 65 years) without a history of CF or similar treatments. Clinical testing included 226-Hz tympanometry, pure-tone air-conduction threshold testing from 0.25 to 16 kHz and bone conduction from 0.25 to 4 kHz. Experimental testing included wideband absorbance at ambient and tympanometric peak pressure and TEOAEs in three stimulus conditions: at ambient pressure and at tympanometric peak pressure using a chirp stimulus with constant incident pressure level across frequency and at ambient pressure using a chirp stimulus with constant absorbed sound power across frequency.

RESULTS

At the initial visit, behavioral audiometric results indicated that 76 of the 157 ears (48%) from patients with CF had normal hearing, whereas 81 of these ears (52%) had sensorineural hearing loss for at least one frequency. Seven ears from four patients had a confirmed behavioral change in hearing threshold for ≥3 visits during study participation. Receiver operating characteristic curve analyses demonstrated that all three TEOAE conditions were useful for distinguishing CF ears with normal hearing from ears with sensorineural hearing loss, with an area under the receiver operating characteristic curve values ranging from 0.78 to 0.92 across methods for frequency bands from 2.8 to 8 kHz. Case studies are presented to illustrate the relationship between changes in audiometric thresholds, TEOAEs, and absorbance across study visits. Absorbance measures permitted identification of potential middle ear dysfunction at 5.7 kHz in an ear that exhibited a temporary hearing loss.

CONCLUSIONS

The joint use of TEOAEs and absorbance has the potential to explain fluctuations in audiometric thresholds due to changes in cochlear function, middle ear function, or both. These findings are encouraging for the joint use of TEOAE and wideband absorbance objective tests for monitoring ototoxicity, particularly, in patients who may be too ill for behavioral hearing tests. Additional longitudinal studies are needed in a larger number of CF patients receiving ototoxic drugs to further evaluate the clinical utility of these measures in an ototoxic monitoring program.

[Drug-induced hearing loss as a manifestation of drug-induced ototoxicity]

The ability of drugs to have an ototoxic effect has been studied for a long time, however, the true prevalence of this undesirable phenomenon is unknown, which is due to the use of various audiological protocols, a wide range of reactions to drugs in different ethnic groups, and most importantly, the lack of caution with regard to otological symptoms due to their reversibility or lack of immediate threat to life. Drug-induced ototoxicity is a functional disorder of the inner ear (cochlea and/or vestibular apparatus) or eighth pair of cranial nerves. Pharmacotherapy, associated with the development of ototoxic drug reactions, may remain undervalued for a long time, often until irreversible hearing impairment is formed. The most frequently prescribed drugs that cause ototoxic phenomena include anticancer drugs, antibacterial drugs of the aminoglycoside group, loop diuretics, calcium channel blockers, non-steroidal anti-inflammatory drugs, antimalarial drugs, salicylates, etc. Monitoring the degree of hearing impairment before and during therapy is important in preventing the development of drug-induced ototoxicity and makes it possible to consider alternative treatment regimens in a timely manner. It is in this connection that the role of participation in the appointment of rational pharmacotherapy to patients with a potential risk of developing otological phenomena of a clinical pharmacologist and audiologist undoubtedly increases.

Peripheral Facial Palsy in Emergency Department

INTRODUCTION

Peripheral facial palsy (PFP) is commonly diagnosed in every emergency department. Despite being a benign condition in most cases, PFP causes loss in quality of life mostly due to facial dysmorphia. The etiology of PFP remains unknown in most cases, while medical opinion on epidemiology, risk factors and optimal treatment is not consensual. The aim of this study was to review the demographic characteristics of our patients and the medical care administered in our emergency department.

MATERIALS AND METHODS

Emergency episodes occurring in a 4-year period and codified as facial nerve pathology were analyzed. IBM SPSS software was used for statistical analysis.

RESULTS

In total, 582 emergency episodes were obtained. Due to inexpressive representation of other causes of PFP in our study, we focused our analyses on the 495 patients who were considered to have idiopathic PFP. There was equal distribution among genders, and all age ranges were affected. There were no clear epidemic phenomena. Hypertension was not a statistically significant risk factor for Bell's palsy. Most patients sought medical care in the early stages of the disease and complained of isolated facial weakness. Most patients had mild-to-moderate symptoms. Previous upper way infections (PUAI) were more frequent among children. There was a statistically significant difference regarding computed tomography (CT) scan requests among specialties.

CONCLUSION

Epidemiologic findings were consistent with most literature on Bell's palsy. Drug therapy is widely used and follows current guidelines. The role of PUAI in the pediatric population must be investigated. Despite evidence of good medical practice, there was an excess of CT scans requested by physicians other than otorhinolaryngologists.

Ototoxicity: A Challenge in Diagnosis and Treatment

Ototoxicity is the pharmacological adverse reaction affecting the inner ear or auditory nerve, characterized by cochlear or vestibular dysfunction. The panorama of drug-induced hearing loss has widened over last few decades. Although ototoxic medications play an imperative role in modern medicine, they have the capacity to cause harm and lead to significant morbidity. Evidence has shown early detection of toxicity through prospective ototoxicity monitoring allows for consideration of treatment modifications to minimize or prevent permanent hearing loss and balance impairment. Although many ototoxicity monitoring protocols exist, their practicality is questionable due to several factors. Even though the existing protocols have proven to be effective, certain lacunae in practice have been encountered due to discrepancies among recommended protocols. Implementation of these protocols is mostly held back due to the incapacitated status of the patient. The choice of early ototoxicity identification techniques is still debatable due to variables such as high degree of sensitivity, specificity and reliability, less time consumption and less labour-intensive to the patient. Hence, the diagnosis and effective treatment of ototoxicity is challenging, even today. A stringent protocol with more practicality encompassing all elements aimed at profiling the effects of ototoxicity is greatly needed. This review describes an efficient application of ototoxicity monitoring and treatment protocol as an attempt to reduce the challenges in diagnosis and management of ototoxicity.

Clinical trials, ototoxicity grading scales and the audiologist's role in therapeutic decision making

OBJECTIVES

Define clinical trials and adverse event (AE) monitoring from the perspective of the audiologist. Rationalise the importance of audiology's involvement before, during and after monitoring. Identify strengths and weaknesses in toxicity grading scales, and discuss factors that may influence these.

DESIGN

Literature involving commonly cited grading scales used to capture ototoxicity is reviewed. Current regulations and language associated with clinical trial implementation and AE monitoring are described. Personal observations based on a variety of clinical populations are drawn from years of experience developing and employing ototoxicity monitoring protocols in a complex medical setting.

RESULTS

Six commonly used grading scales for ototoxicity are systematically reviewed for strengths and weaknesses. Necessary considerations that inform selection of grading scales are presented. A review of and historical context for clinical trial development and AE monitoring is provided.

CONCLUSIONS

The audiologist's role in therapeutic decision making goes beyond collection of the audiogram. Clear communication to stakeholders in ototoxicity monitoring is paramount, and toxicity grading scales are one tool to facilitate this exchange. Various factors should be considered in advance of selecting the most appropriate scale to capture hearing loss, and no scale is without limitation.

Alterations in Evoked Otoacoustic Emissions by the Use of Meglumine Antimoniate in American Tegumentary Leishmaniasis Patients

INTRODUCTION

Tegumentary Leishmaniasis (TL) is a neglected, non-contagious, infectious disease, caused by different protozoa species of the Leishmania genus that affects skin and mucous membranes. Meglumine Antimoniate (MA), the first drug of choice for TL treatment in Brazil, has already been associated with cochlear toxicity, which is defined as damages of the cochlea caused by exposure to chemical substances, resulting in reversible or irreversible hearing loss. Auditory monitoring for cochlear toxicity aims at the early detection of auditory disorders, enabling, when possible, hearing to be preserved or an early auditory rehabilitation. Although otoacoustic emissions (OAEs) are used in this monitoring, there is no consensus on the criteria that define cochlear toxicity by this examination. The objective of this study was to describe the characteristics of the OAEs in cochlear toxicity monitoring in TL patients using MA.

METHODS

Prospective and longitudinal study of auditory monitoring of 35 patients with parasitological diagnosis of TL, with liminal tonal audiometry, high frequency audiometry, immitanciometry, distortion product evoked otoacoustic emissions (DPEOAEs) and transient evoked otoacoustic emissions (TEOAEs) before treatment, at the end of treatment, one month after the end of treatment and two months after the end of treatment.

RESULTS

80% male, with median age of 44 years (IIQ: 22-59). In the pre-treatment evaluation: 11.4% complained of hearing loss and 20% of tinnitus, 48.6% presented auditory alterations in liminal tonal audiometry (LTA, 65.2% in high frequency audiometry (HFA), 26.6% in DPEOAE and 51.4% in TEOAE. No association was verified between genre and alterations in the EOAE examinations. We observed that patients that presented disorders in DPEOAE examinations were 17 years older than those without alterations and that patients that showed disorders in TEOAEO examinations were 34 years older than those without disorders. The presence of alterations in DPEOAE and TEOAE before beginning treatment was associated with each other and with the presence of alterations in LTA and HFA, and only DPEOAE was associated with hearing loss. We observed a significantly higher number of alterations of DPEOAE at the end of treatment than during pre-treatment and values of the ratio signal/noise significantly smaller at the end of treatment than during pre-treatment in the frequencies of 2 kHz (difference of 1.7dB; p = 0.016) and 4 kHz (difference of 2.45dB; p = 0.016) in DPEOAE and in the range 1.75/2.5 kHz in TEOAE (difference of 2.9dB; p = 0.039).

CONCLUSION

The ototoxic signals observed in our study using EOAE indicated that both, DPEOAE and TEOAE are adequate and sensitive techniques for clinical monitoring of ototoxicity by MA. Their application is very simple, and their results help the physician to take the most adequate steps for each patient, thus avoiding permanent hearing damage.

Risk versus Benefit: Who Assesses this in the Management of Patients on Ototoxic Drugs?

The current paper is an attempt at highlighting important strategic indicators, as well as important variables, that the audiology community needs to consider in order to play a more central role in pharmaco-vigilance as part of pharmaco-audiology. Pharmaco-vigilance is an important aspect of pharmacological treatment of disease. In developing countries, where burden of disease is high with resource constraints dictating healthcare priorities; it is important to deliberate on risk/benefit of medications prescribed to treat disease. In the form of a literature review, the author presents current arguments with regards to audiology practice. In audiology, pharmaco-vigilance in the form of ototoxicity monitoring is gaining momentum within the South African research and clinical communities. This ototoxicity monitoring is however non-systematic, non-comprehensive, and does not seem to have a strategic plan behind it. This is fundamentally due to lack of involvement of audiologists in the risk/benefit evaluation of medications during the drug development and monitoring process. The current paper agues for an expanded role of the Audiologist which will ensure collaborative engagement with all relevant stakeholders in order to ensure that both quantity and quality of life are considered during the drug development and monitoring process.

Meta-Analysis of Distortion Product Otoacoustic Emission Retest Variability for Serial Monitoring of Cochlear Function in Adults

OBJECTIVE

Distortion product otoacoustic emissions (DPOAEs) have long been heralded as a means to objectively monitor cochlear function and increasingly are becoming a key component in hearing surveillance programs for individuals at risk for ototoxic- and occupational noise-related hearing loss. Yet clinicians are unsure how to define clinically meaningful shifts in DPOAE level. In this study, a meta-analysis approach is used to synthesize the DPOAE level test-retest literature to construct a set of DPOAE level shift reference limits that can be used clinically to define a statistically significant emission change.

DESIGN

The authors reviewed all published articles identified through a Medline search using the terms "Otoacoustic Emission Variability," "Otoacoustic Emission Reliability," "Otoacoustic Emission Repeatability," and "Otoacoustic Emission Test Retest" restricted to DPOAEs, adults, and English language. Articles with DPOAE level data elicited by moderate stimulus levels for f2 frequencies of 1000, 2000, 4000, or 6000 Hz were selected because these stimulus parameters were relatively well represented in the literature. The authors only included articles that reported the standard error of the measurement (SEM) or from which the SEM could be calculated. Meta-analysis was used to estimate the population mean SEM over the included studies. Models were fit separately for each f2 primary and included days since baseline and study-specific random effects.

RESULTS

Ten DPOAE test-retest studies met inclusion criteria for this meta-analysis. The SEM values varied widely across published studies (0.57 to 3.9 dB) and were provided for relatively short time intervals (less than 15 days on average). Time, or days since baseline, was statistically significant at higher f2 frequencies (4000 and 6000 Hz). From the model results, 90% reference limits specific to the f2 and elapsed time between baseline and follow-up measurements were established. Reference limits provided correspond to negative (emission decrement) and positive (emission enhancement) shifts indicative of the amount of measurement variability that, using this approach, must be tolerated as "normal" fluctuations over time. Changes larger than the reference limits are considered significant and warrant follow-up testing.

CONCLUSIONS

The meta-analysis presented provides reference limits that are appropriate for a set of specific f2 frequencies and time intervals. The meta-analysis concerns the SEM statistic directly, so that any preferred reference limit can be computed from the results and should be predicated upon the screening application. The presumed advantage of this meta-analytic approach is increased precision relative to limits suggested by any of the individual studies included in the analysis.

Ototoxicity (cochleotoxicity) classifications: A review

OBJECTIVE

Drug-mediated ototoxicity, specifically cochleotoxicity, is a concern for patients receiving medications for the treatment of serious illness. A number of classification schemes exist, most of which are based on pure-tone audiometry, in order to assist non-audiological/non-otological specialists in the identification and monitoring of iatrogenic hearing loss. This review identifies the primary classification systems used in cochleototoxicity monitoring. By bringing together classifications published in discipline-specific literature, the paper aims to increase awareness of their relative strengths and limitations in the assessment and monitoring of ototoxic hearing loss and to indicate how future classification systems may improve upon the status-quo.

DESIGN

Literature review.

STUDY SAMPLE

PubMed identified 4878 articles containing the search term ototox*.

RESULTS

A systematic search identified 13 key classification systems. Cochleotoxicity classification systems can be divided into those which focus on hearing change from a baseline audiogram and those that focus on the functional impact of the hearing loss.

CONCLUSIONS

Common weaknesses of these grading scales included a lack of sensitivity to small adverse changes in hearing thresholds, a lack of high-frequency audiometry (>8 kHz), and lack of indication of which changes are likely to be clinically significant for communication and quality of life.

Effect of sepsis and systemic inflammatory response syndrome on neonatal hearing screening outcomes following gentamicin exposure

OBJECTIVES

Hearing loss in neonatal intensive care unit (NICU) graduates range from 2% to 15% compared to 0.3% in full-term births, and the etiology of this discrepancy remains unknown. The majority of NICU admissions receive potentially ototoxic aminoglycoside therapy, such as gentamicin, for presumed sepsis. Endotoxemia and inflammation are associated with increased cochlear uptake of aminoglycosides and potentiated ototoxicity in mice. We tested the hypothesis that sepsis or systemic inflammatory response syndrome (SIRS) and intravenous gentamicin exposure increases the risk of hearing loss in NICU admissions.

METHODS

The Institutional Review Board at Oregon Health & Science University (OHSU) approved this study design. Two hundred and eight infants met initial criteria, and written, informed consent were obtained from parents or guardians of 103 subjects ultimately enrolled in this study. Prospective data from 91 of the enrolled subjects at OHSU Doernbecher Children's Hospital Neonatal Care Center were processed. Distortion product otoacoustic emissions (DPOAEs; f2 frequency range: 2063-10,031 Hz) were obtained prior to discharge to assess auditory performance. To pass the DPOAE screen, normal responses in >6 of 10 frequencies in both ears were required; otherwise the subject was considered a "referral" for a diagnostic hearing evaluation after discharge. Cumulative dosing data and diagnosis of neonatal sepsis or SIRS were obtained from OHSU's electronic health record system, and the data processed to obtain risk ratios.

RESULTS

Using these DPOAE screening criteria, 36 (39.5%) subjects would be referred. Seventy-four (81%) subjects had intravenous gentamicin exposure. Twenty (22%) had ≥4 days of gentamicin, and 71 (78%) had <4 days. The risk ratio (RR) of referral with ≥4 days of gentamicin was 1.92 (p=0.01). Eighteen subjects had sepsis or met neonatal SIRS criteria, 9 of whom had ≥5 days of gentamicin and a DPOAE referral risk ratio of 2.12 (p=0.02) compared to all other subjects. Combining subjects with either vancomycin or furosemide overlap with gentamicin treatment yielded an almost significant risk ratio (RR=1.77, p=0.05) compared to the rest of the cohort.

CONCLUSIONS

We report an increased risk of referral with DPOAE screening for those receiving ≥4 days of intravenous gentamicin administration that may contribute to the greater prevalence of hearing loss in NICU graduates. We propose an expanded prospective study to gather a larger cohort of subjects, identifying those with sepsis or neonatal SIRS, to increase the statistical power of this study design. Subsequent studies also need to obtain follow-up diagnostic audiological data to verify whether the outcomes of DPOAE screening, in addition to the standard AABR screen, is a reliable predictor of permanent hearing loss following gentamicin exposure in the NICU.