Sudden Hearing Loss: Updated Clinical Practice Guideline

Sudden hearing loss (SHL), defined as a rapid-onset subjective sensation of hearing impairment in one or both ears is an emergency in the ear-nose-throat clinical practice.

If not recognized and managed promptly, sudden hearing loss may result in persistent hearing loss and tinnitus and reduced patient quality of life.

The disease affects 5 to 27 per 100,000 people annually. About 66,000 new cases are reported per year in the United States.

Sudden sensory neural hearing loss (SSNHL) is a subset of SHL that is (a) sensorineural in nature, (b) occurs within a 72-hour window, and (c) consists of a decrease in hearing of 30 decibels affecting at least 3 consecutive frequencies. Idiopathic sudden sensorineural hearing loss (ISSNHL) is SSNHL with no identifiable cause despite adequate investigation.

Studies have even found that sudden sensory neural hearing loss may be an early predictor of future cerebrovascular accidents.

Recently, the American Academy of Otolaryngology and Head & Neck Surgery (AAOHNS)’s team, headed by Dr. Sujana S. Chandrasekhar MD, came up with updated guidelines for diagnosis, management, and follow-up of patients with SHL aged 18 years and above.

These guidelines provide evidence-based recommendations and treatment for the patients presenting with SHL.

The guideline update group made the following key action statements (KAS).

Strong recommendations for the following:

• KAS 1: Clinicians should distinguish sensorineural hearing loss from conductive hearing loss when a patient first presents with SHL.
• KAS 7: Clinicians should educate patients with sudden sensorineural hearing loss about the natural history of the condition, the benefits, and risks of medical interventions, and the limitations of existing evidence regarding efficacy.
• KAS 13: Clinicians should counsel patients with sudden sensorineural hearing loss who have residual hearing loss and/or tinnitus about the possible benefits of audiologic rehabilitation and other supportive measures.

A strong recommendation means that the benefits of the recommended approach clearly exceed the harms (or, in the case of a strong negative recommendation, that the harms clearly exceed the benefits) and that the quality of the supporting evidence is high (grade A or B). Clinicians should follow a strong recommendation unless a clear and compelling rationale for an alternative approach is present.

Strong recommendations against the following:

• KAS 3: Clinicians should not order routine computed tomography of the head in the initial evaluation of a patient with presumptive sudden sensorineural hearing loss.
• KAS 5: Clinicians should not obtain routine laboratory tests in patients with sudden sensorineural hearing loss.
• KAS 11: Clinicians should not routinely prescribe antivirals, thrombolytics, vasodilators, or vasoactive substances to patients with sudden sensorineural hearing loss

Recommends the following:

• KAS 2: Clinicians should assess patients with presumptive sudden sensorineural hearing loss through history and physical examination for bilateral SHL, recurrent episodes of SHL, and/or focal neurologic findings.
• KAS 4: In patients with SHL, clinicians should obtain, or refer to a clinician who can obtain, audiometry as soon as possible (within 14 days of symptom onset) to confirm the diagnosis of sudden sensorineural hearing loss.
• KAS 6: Clinicians should evaluate patients with sudden sensorineural hearing loss for retro cochlear pathology by obtaining magnetic resonance imaging or auditory brainstem response.
• KAS 10: Clinicians should offer, or refer to a clinician who can offer, intratympanic steroid therapy when patients have incomplete recovery from sudden sensorineural hearing loss 2 to 6 weeks after onset of symptoms.
• KAS 12: Clinicians should obtain follow-up audiometric evaluations for patients with sudden sensorineural hearing loss at the conclusion of treatment and within 6 months of completion of treatment.

A recommendation means that the benefits exceed the harms (or, in the case of a negative recommendation, that the harms exceed the benefits), but the quality of evidence is not as high (grade B or C). Clinicians should also generally follow a recommendation but should remain alert to new information and sensitive to patient preferences.

Options

• KAS 8: Clinicians may offer corticosteroids as initial therapy to patients with sudden sensorineural hearing loss within 2 weeks of symptom onset.
• KAS 9a: Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy within 2 weeks of the onset of sudden sensorineural hearing loss.
• KAS 9b: Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy as salvage therapy within 1 month of onset of sudden sensorineural hearing loss.

An option means that either the quality of evidence is suspect (grade D) or well-done studies (grade A, B, or C) show little clear advantage to one approach versus another. Clinicians should be flexible in their decision making regarding appropriate practice, although they may set bounds on alternatives; patient preference should have a substantial influencing role.

Changes to the KASs from the original guideline:

Following are the key changes to the original 2012, guidelines:

• KAS 1—When a patient first presents with sudden hearing loss, conductive hearing loss should be distinguished from sensorineural.
• KAS 2—The utility of history and physical examination when assessing for modifying factors is emphasized.
• KAS 3—The word ‘‘routine’’ is added to clarify that this statement addresses nontargeted head computerized tomography scan that is often ordered in the emergency room setting for patients presenting with sudden hearing loss. It does not refer to targeted scans, such as temporal bone computerized tomography scan, to assess for temporal bone pathology.
• KAS 4—The importance of audiometric confirmation of hearing status as soon as possible and within 14 days of symptom onset is emphasized.
• KAS 5—New studies were added to confirm the lack of benefit of nontargeted laboratory testing in sudden sensorineural hearing loss.
• KAS 6—Audiometric follow-up is excluded as a reasonable workup for retrocochlear pathology. Magnetic resonance imaging, computerized tomography scan if magnetic resonance imaging cannot be done, and, secondarily, auditory brainstem response evaluation are the modalities recommended. A time frame for such testing is not specified, nor is it specified which clinician should be ordering this workup; however, it is implied that it would be the general or subspecialty otolaryngologist.
• KAS 7—The importance of shared decision making is highlighted, and salient points are emphasized.
• KAS 8—The option for corticosteroid intervention within 2 weeks of symptom onset is emphasized.
• KAS 9—Changed to KAS 9A and 9B. Hyperbaric oxygen therapy remains an option but only when combined with steroid therapy for either initial treatment (9A) or salvage therapy (9B). The timing of initial therapy is within 2 weeks of onset, and that of salvage therapy is within 1 month of onset of sudden sensorineural hearing loss.
• KAS 10—Intratympanic steroid therapy for salvage is recommended within 2 to 6 weeks following the onset of sudden sensorineural hearing loss. The time to treatment is defined and emphasized.
• KAS 11—Antioxidants were removed from the list of interventions that the clinical practice guideline recommends against using.
• KAS 12—Follow-up audiometry at the conclusion of treatment and also within 6 months posttreatment is added.
• KAS 13—This statement on audiologic rehabilitation includes patients who have residual hearing loss and/or tinnitus who may benefit from treatment.

Summary of 2019 updated guidelines

The updated guidelines can be summarized as follows.

References

1. Stachler RJ, Chandrasekhar SS, Archer SM, Rosenfeld RM, Schwartz SR, Barrs DM, Brown SR, Fife TD, Ford P, Ganiats TG, Hollingsworth DB. Clinical practice guideline: sudden hearing loss. Otolaryngology—Head and Neck Surgery. 2012 Mar;146(3_suppl):S1-35.
2. Chandrasekhar SS, Tsai Do BS, Schwartz SR, Bontempo LJ, Faucett EA, Finestone SA, Hollingsworth DB, Kelley DM, Kmucha ST, Moonis G, Poling GL. Clinical practice guideline: sudden hearing loss (update). Otolaryngology–Head and Neck Surgery. 2019 Aug;161(1_suppl):S1-45.