prevention and intervention in clinical practice

www.amtronix.co.za

Ototoxicity

Prevention and intervention in clinical practice

Alida Naudé PhD 2017-10-27 Pine Lodge Conference Centre 14:00-15:00

Who?

Amtronix Diagnostics: Precision is key www.amtronix.co.za

Treating specialist

Dose regulation

Medication changes

Audiologist

Early intervention

Communication strategies

Counselling / Education

Who?


Emotional well-being Reasoning skills Communication

Quality of life Coping skills

Stress

Speech/language development Social-emotional development Lifetime of medical expenses

Educational achievement Reasoning skills

Where?


• Impacts the structure and function of: oVestibular & cochlear hair cells and their

supporting structures oThe vestibulocochlear (VIIIth) nerve

Where?


What?


xxx

• Amikacin, Gentamicin, Neomycin, Kanamycin, Netilmicin, Streptomycin, Tobramycin

Aminoglycoside antibiotics

• Erythromycin, Vancomycin, Chloramphenicol, Furazolidone, Polymyxin B & E, Trimethoprim-sulfamethoxazole Other antibiotics

•Ethacrynic acid, Furosemide, Bumetanide Loop diuretics

•Quinine, Chloroquine, Hydroxychloroquine, Primaquine, Quinidine, Pyrimethamine

Antimalarial drugs

•Aspirin, Nonsteroidal anti-inflammatory agents Salicylates

•Cisplatin, Carboplatin, Oxaliplatin, Nitrogen mustard, Methotrexate, Vincristine, Dactinomycin

Antineoplastic drugs

What?


xxx Over 148 ototoxic chemicals

•benzene, benzyl alcohol, butyl alcohol, carbon disulphide (rubber, cellophane), carbon, tetrachloride, heptane, hexane, styrene, toluene, trichloroethylene and xylene

Organic solvents Skin*

•arsenic, cobalt, lead, manganese,

mercury and trimethyltin Heavy metals

Adhesives, auto emissions, fungicides, glues, grease, spot removers, insecticides, insulation lacquers, liquid correction fluid, organic solvents, paint, paint thinners, resins, room deodorizers, rug cleaners, spray paint, varnishes, and wood preservatives

What?


Combination of stressors Noise +

•Mechanical energy oscillations transferred to the human body •Anterior, posterior SCC & utricular membrane

HAV WBV

•CBV Sympathetic

vasoconstriction

•Smoking •Painkillers •BP •Cholesterol

Life style factors

What?


• Ototoxicity o Difficult to predict; poorly correlated with dosage, peak serum

levels, development of other toxicities e.g. renal toxicity • Depends on dosage, age, genetics, and concurrent exposure to

noise or other chemicals/drugs • Effects of multiple ototoxic agents may be synergistic, antagonistic,

and nonlinear

What?


• Audiological evaluation • Case history

• Think drugs • Concurrently taking drugs, order of taking drugs • Synergistic relationship between drugs and noise

Aspirin, Cisplatin, Chlorampehnicol, Gentamicin, Kanamycin Gain & MPO

Everyday practice: Case History


• Thorough and complete history • Impact current status • Impact future-based medical decision making

o Get the name o Ototoxic Drugs Exposed o Index of suspicion o Ototoxic drug list

Symptoms


• Hearing loss (permanent, temporary, varying degree, from high to low frequencies)

• Tinnitus • Hyperacusis • Aural fullness • Imbalance/dizziness

Clinical objectives


1. Pretreatment ototoxicity risk assessment to demonstrate the anticipated hearing loss in the conventional frequency range as a result of the prescribed dosing schedule.

2. Screening for early hearing changes to identify any ASHA-significant hearing shift within each patient’s individualized SRO, as measured directly using pure-tone threshold testing or estimated using DPOAE testing.

3. Screening for outer hair cell dysfunction DPOAEs to identify early, potentially preclinical damage.

4. Screen failure follow-up testing to determine the extent that hearing changes include frequencies in the conventional audiometric frequency range as measured directly using pure-tone threshold testing or estimated using DPOAE testing.

5. Screening for tinnitus to determine whether the drug treatment is instigating or exacerbating tinnitus and the need for a tinnitus management referral.

6. Patient and provider education about ototoxic-induced hearing and tinnitus, synergistic effects of ototoxins and noise overexposure, and rehabilitative solutions to hearing loss and tinnitus.

Clinical picture


• Hearing loss and tinnitus • Impaired central auditory processing

o Synergistic relationship between chemical and noise Arsenic, butyl alcohol, butyl nitrite, heptane, hexane,

manganese, mercury and trimethyltin 11-20 times increased risk

What?


• Audiological evaluation o Otoscopic examination o Tympanometry (incl acoustic reflexes) o Behavioral audiometry o Speech audiometry o OAEs o Staggered spondaic word test (SSW) o ABR


<8 000 Hz (36% - Fausti et al., 2003)

Monitoring: Sensitivity range for ototoxicity air conduction (SRO), Otoscopy & tympanometry

Length of test, lack of equipment OAE

I/O function fine step frequency measures Test-retest reference limits Limited, protocol consistency

One method limitations Formal tinnitus monitoring procedures

No results for universal Grading of hearing loss

Chang Scale, Brock’s hearing loss grades, NCI CTCAE grades for children

QOL

Reflection on practices


Reflection on practices QOL


The perception (physical and mental well-being) of the individual and not just their functional status

• Hearing handicap inventory for adults (HHIA) • Health-related quality of life questionnaire (HRQOL) • PedsdQLTM ( 6-18y) • Hearing handicap inventory for the elderly (HHIE-S) • Youth quality of life instrument – Deaf and hard of hearing module • Dizziness handicap inventory (DHI)

When?


Baseline

M1 M2 M3

Post treatment

Long-term follow-up

TREATMENT

Design individualized monitoring programme

Adapted from Kathleen Campbell

Identify patients needing ototoxicity monitoring

Responsive Limited Responsive Non-Responsive

Soundproof booth Soundproof booth Soundproof booth Ward Ward Ward

Control noise Control noise Control noise

Full Audiometric Assessment Subjective measures Objective measures

Limited time: Subjective + Objective measures Objective measures

BASELINE MEASUREMENT

IN TREATMENT MONITORING / FOLLOW UP MEASUREMENT

POST TREATMENT MONITORING / FOLLOW UP MEASUREMENT

Tinnitus, noise and hearing surveys Otoscopy (video vs normal) Tympanometry and reflexes

Pulsed Pure tone AC/BC (extended high freq) Establish sensitivity range for ototoxicity (SRO)

Speech audiometry / DPOAE or ABR

Otoscopy Tympanometry and reflexes

DPOAE or ABR

Tinnitus, noise and hearing surveys Otoscopy

Tympanometry and reflexes Pure tone AC/BC and establish SRO

DPOAE (DP/TE/SF) or ABR

Tinnitus and noise surveys Otoscopy

Tympanometry and reflexes SRO (top freq ≤100dB + 6 below

DPOAE or ABR screen If changes – repeat

Tinnitus and noise surveys Otoscopy

Tympanometry and reflexes SRO

DPOAE or ABR screen If changes - repeat

Otoscopy Tympanometry and reflexes

DPOAE or ABR screen If changes - repeat

Inform team of any changes, continue monitoring

Monitoring protocol: 1 month / 3 months Baseline protocol: 6 months

Asha 1994

Repeated change ≥20 dB PTT change at 1 freq

≥10 dB PTT change at 2 adj freq Loss of response at 3 adj freq

2.4 dB 2002 / 7dB 2003 / 3-6dB 2011

Sensitive (> hit rate) Specific (< false positive rate)

Reliable (< test-retest variability)

Terminate, change or alter dose

Q U A L I T Y O F L I F E

Age

Threshold detection method Earphones Calibration

Intersubject variability

How?


Assessment of hearing Assessment of balance

Baseline: PT pulsed 0.5, 1,2,3,4,6,8,9,10,11.2,12.5,14,16,18,20

Bedside DVA vHIT Head shake Postural control VNG Rotational testing

Documenting: Threshold detection method,

earphones

Why?


1. Educate: Patients, caregivers, physicians 2. Counseling

• Potential impacts on auditory system • Signs and symptoms • Potential effects of noise exposure • Communication strategies

3. Early intervention critical for maintenance of QOL 4. Rehabilitation with use of amplification 5. Vestibular rehabilitation 6. TOMI


Informed consent: Aware of side effects Alternative treatment Children

Implementation: Lack of education Time-consuming procedures Equipment / resources / staff Averse to vestibular testing Discharge from hospital Medical aid / keeping cost in check Cooperation Professional skill

(subjective complaints + risk identification, CPD)


Record keeping – documentation

Research

Quality of life: returning to work etc

Under reporting due to fear of medico-legal issues

Infection control

Ototoxicity


xxx


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prevention and intervention in clinical practice

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