Treatment Protocol Guidelines
The following hyperbaric medicine treatment protocol is based upon the recommendations of the Hyperbaric Oxygen Committee of the Undersea and Hyperbaric Medical Society. Clinical protocols and/or practice guidelines are systematically developed statements that help physicians, other practitioners, case managers and clients make decisions about appropriate health care for specific clinical circumstances.
Protocols allow health providers to offer evidence-based, appropriate, standardized diagnostic treatment and care services to patients undergoing hyperbaric oxygen therapy (HBOT). Evidenced-based medicine offers clinicians a way to achieve
improved quality, improved patient satisfaction, and reduced costs.
This topic discusses Idiopathic Sudden Sensorineural Hearing Loss (ISSHL).
Utilization Review
should be initiated when clinical decisions result in deviation from or modification of treatment protocols. This includes any course of treatment at or above the recognized threshold limits.
Medical Necessity
Medicare.gov
defines “medically necessary” as “health-care services or supplies needed to prevent, diagnose, or treat an illness, injury, condition, disease, or its symptoms and that meet accepted standards of medicine.”
The following condition is NOT a covered indication per the National Coverage Determination (NCD) 20.29.[1]
This medical condition shall not be treated adjunctively or primarily by HBOT for reimbursement by the Medicare program as data supporting its use has not been established as medically beneficial. Services deemed treatment for these primary conditions will be denied as Not Reasonable and Necessary.
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Sample Physician Order |
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ICD-10 Crosswalk |
Treatment Table
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Emergent / Urgent Indication
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Background
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The specific pathophysiology of Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) remain unclear. The current theory is that URI/viral episodes create an inflammatory condition of the cochlea resulting in sudden/acute hearing degradation, usually unilaterally. Multiple drug regimens have been used with moderate success. Addition of adjunctive HBOT in addition to drug regimens including anti-viral medications and corticosteroids has been shown to impart a 37.7 dB improvement in hearing in those with severe hearing loss and a 19.3 dB gain in those with moderate hearing loss.[2] This brings the hearing deficits from a moderate/severe range into a slight/no impairment range (e.g., from virtually no discernible voice recognition to clear voice recognition).
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Goals of HBO
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- Increase intra-cochlear oxygen tensions
- Reduce inflammation and edema
- Prevent or decrease ischemia-reperfusion injury
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Diagnosis
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ISSHL is clinically defined as a hearing loss of at least 30 dB occurring within 3 days over at least 3 contiguous frequency ranges. The common presentation is unilateral hearing loss, tinnitus, a sensation of aural fullness, and dizziness or vertigo
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Hyperbaric Criteria
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- ISSHL within the moderate or worse range (>40 dB) who present within 14 days of symptom onset. Some studies have shown improvement when patients present up to 30 days after onset of symptoms. However, it is clear that patients presenting early have better hearing outcomes. Be aware that some insurers will refuse coverage for any delay longer than 14 days. Do not postpone evaluation of these patients because all delays may cause denials of coverage.
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Complete evaluation by an otolaryngologist and audiologist with appropriate imaging and hearing tests.
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We suggest that you submit copies of the audiogram and interpretation with your hyperbaric history and physical examination. Draw attention to the 3 contiguous frequencies and the profound hearing loss at those frequencies.
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Evaluation
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- Past medical history: duration of hearing loss at presentation, presence of various co-morbid factors such as diabetes, hypertension, and autoimmune disorders. History of trauma, straining, diving, flying, and intense noise exposure was noted.
- Physical examination: the most common clinical presentation is sudden unilateral hearing loss, tinnitus, aural fullness, and vertigo.
- Chest x-ray and electrocardiogram (ECG) as required.
- Consultation with ENT surgeon to rule out mass lesions of the eighth cranial nerve. A common cause of unilateral hearing loss is an acoustic neuroma. There will be no response to HBOT in this diagnosis. That said, nearly all ENT surgeons will order an MRI or CT scan to rule out this diagnosis.
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Treatment
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- Patients with ISSHL should be treated with anti-virals and corticosteroids with decongestants and appropriate medical management
- Consider corticosteroid initial dose of 1mg/kg/day and taper dosing over two to three weeks.
- Intratympanic corticosteroids may be an alternative in those with contraindications to oral steroids.
- Hyperbaric oxygen therapy at 2 or 2.5 ATA oxygen for 90 minutes.
- If treating at 2.5 ATA, administer 5-10 minute air breaks at 30 and 60-minutes of breathing oxygen. (Table 1 or Table 3)
- Treatments are provided daily for 10 to 20 treatments. There is no support for more than 1 treatment per day.
- Re-evaluate following 10 treatments, in coordination with the referring specialist. Most third party insurers will require this evaluation and a repeat audiogram documenting certain levels of improved hearing over the frequencies originally lost.
- Periodic reassessment by the otolaryngologist and/or audiologist.
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Follow-Up
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- Audiometric evaluation within six months of diagnosis
- Visual acuity assessment for progressive myopia
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Treatment Threshold
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Concurrent: After 10 treatments: Must include audiogram evidence of improvement; Third party peer review: 20 treatments (See
Utilization/Peer Review
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Coding
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Refer to the ICD-10 Guideline for the appropriate ICD-10 code
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Comments
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- If diabetes mellitus, blood glucose should be checked within an hour prior to treatment and immediately post-HBOT.
- Nine of 11 studies in the scientific literature demonstrate positive results with the addition of HBOT to the treatment regimen.
- This indication is not covered by Medicare but may be covered by some commercial carriers. Medicare patients must sign an Advanced Beneficiary Notice (ABN) to receive HBO treatment.
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Primary Sources:
Whelan and Kindwall [3]
, Weaver
[4][5]
DOCUMENTATION
History
Sample documentation for Idiopathic Sudden Sensorineural Hearing Loss is shown below:
"Mrs. Jones is a 56 y/o woman who was in her usual state of health until 2 weeks ago. At that time, she thought she may have had a viral URI and some stuffiness in her bilateral ears. She awakened from sleep with profound hearing loss in her left ear. This happened suddenly and was quite different from the right. She initially had vertigo associated with the difference in hearing between the two ears. She was seen by her ENT surgeon and had a thorough workup for sudden hearing loss. This included an audiogram showing more than 30dB loss in 4 contiguous tone segments. She had a CT of the head/sinuses and no tumors were found. Her tympanogram was normal.
The ENT surgeon diagnosed Idiopathic Sudden Sensorineural Hearing Loss. The surgeon injected steroids in the tympanic membrane of the affected ear. The patient was taking high dose corticosteroids and anti-viral medications. The patient is now 14 days post-event and has had no improvement in hearing. Today's audiogram was unchanged from her first one.
Mrs. Jones has come to us for adjunctive hyperbaric oxygen therapy. We are happy to assist with her care and will do so in conjunction with her ENT surgeon."
Physical Exam
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The most common clinical presentation is sudden unilateral hearing loss, tinnitus, aural fullness, and vertigo.
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Various co-morbid factors such as diabetes, hypertension, and autoimmune disorders may be present.
Impression
- Idiopathic Sudden Sensorineural Hearing Loss
Refer to ICD-10 Crosswalk
Plan
A typical hyperbaric regimen for a patient with ISSHL consists of daily 2.0 to 2.5 atmospheres absolute hyperbaric oxygen treatments. Oxygen breathing for 90 minutes of treatment will be performed. The patient will be periodically examined by the otolaryngologist and/or audiologist. Clinical review will be undertaken at a total of 20 treatments. There is no data to suggest benefit beyond 20 treatments.
Risk and Benefit of Hyperbaric Oxygen Therapy
- Please refer to topic:
"Documentation HBO: Risks and Benefits"
Indication for Hyperbaric Oxygen Therapy (HBOT)
"Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is clinically defined as a hearing loss of at least 30 dB occurring within 3 days over at least 3 contiguous frequency ranges. The common presentation is unilateral hearing loss, tinnitus, a sensation of aural fullness, and dizziness or vertigo. The ear, nose, and throat surgeon will have ruled out mass lesions of the eighth cranial nerve. The specific etiologies of this syndrome remain unclear and multiple drug regimens have been used with moderate success.
Addition of hyperbaric oxygen therapy in addition to drug regimens has been shown to impart a 37.7 dB improvement in hearing in those with severe hearing loss and a 19.3 dB gain in those with moderate hearing loss. Nine of 11 studies in the literature demonstrate positive results with addition of HBOT to the treatment regimen.
Patient selection criteria include patients with the collection of signs and symptoms above who present during the first two weeks after symptom onset. The patient should be evaluated carefully by an otolaryngologist and audiologist with appropriate imaging and hearing tests performed. In addition to appropriate medical management, hyperbaric oxygen should be administered."
Sample Order
- See Sample Physician Order
CLINICAL EVIDENCE AND RECOMMENDATIONS
- For patients with unilateral ISSNHL not related to any other etiology, with severe to profound hearing loss at baseline, who have been treated with systemic/ intratympanic steroids and acyclovir, and have presented for HBOT in less than 14 days, we suggest adjunct HBOT to improve hearing, compared to standard treatment alone (Grade 2C).
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Rationale: Based on 2 meta-analyses [6][7], we found that use of adjunct HBOT to treat ISSNHL is supported by low certainty evidence. This may only be true if HBOT is used within two weeks of the onset of problems. There is no evidence that HBOT can help people who have been deaf for some months. Further research is needed. The studies included in the meta-analyses presented design problems that resulted in a low certainty recommendation, which include: small number of studies, modest number of patients, methodological variation (differing oxygen dosage and pressure), and reporting inadequacies. Use of HBOT in this context should present no downside except for a small incidence of ear barotrauma (see topic "
Documentation: HBO Risks and Benefits
"). HBOT for ISSNHL is not a covered condition for Medicare and private insurers may have different coverage policies for this condition. Providers are encouraged to check policies prior to ordering HBOT. As for threshold/utilization review, private insurers will review on a case by case basis. This may be 10 treatments approved with a repeated audiogram and demonstrable improvement in hearing. The total number of treatments should not to exceed 20.
APPENDIX
Summary of Evidence
Systematic reviews and meta-analyses
- A 2018 Korean meta-analysis evaluated 3 randomized clinical trials and 16 nonrandomized studies comparing outcomes after HBOT + MT vs MT alone in 2401 patients with ISSNHL (mean age, 45.4 years; 55.3% female) were included.[6]
Pooled odds ratios (ORs) for complete hearing recovery and any hearing recovery were significantly higher in the HBOT + MT group than in the MT alone group (complete hearing recovery OR, 1.61; 95% CI, 1.05-2.44 and any hearing recovery OR, 1.43; 95% CI, 1.20-1.67). Absolute hearing gain was also significantly greater in the HBOT + MT group than in the MT alone group. The benefit of HBOT was greater in groups with severe to profound hearing loss at baseline, HBOT as a salvage treatment, and a total HBOT duration of at least 1200 minutes. Authors concluded that the addition of HBOT to standard MT is a reasonable treatment option for SSNHL, particularly for those patients with severe to profound hearing loss at baseline and those who undergo HBOT as a salvage treatment with a prolonged duration. Optimal criteria for patient selection and a standardized regimen for HBOT should be applied in routine practice, with future trials to investigate maximal treatment benefit. Multiple small trials with small numbers increase heterogeneity, which may discount stronger conclusions. Because of the rarity of the diagnosis, large trials are not easy to perform.[7] To summarize the major deficiencies in scientific investigation for ISSNHL and HBOT: In the published studies, there is variation of treatment protocol for the HBOT group (pressure used, time breathing oxygen, interrupting treatments for weekends/holidays, total number of treatments, etc.). When analyzed using GRADE methodology, this shows up as increased heterogeneity, and it diminishes the ability to give a powerful recommendation. Hence, most recommendations for HBOT and ISSNHL are low to moderate benefit.
- A 2012 Cochrane database meta-analysis evaluated 7 trials (392 participants).[8] The studies were small and of generally poor quality. Pooled data from two trials did not show any significant improvement in the chance of a 50% increase in hearing threshold on pure-tone average with HBOT (risk ratio (RR) with HBOT 1.53, 95% confidence interval (CI) 0.85 to 2.78, P = 0.16), but did show a significantly increased chance of a 25% increase in pure-tone average (RR 1.39, 95% CI 1.05 to 1.84, P = 0.02). There was a 22% greater chance of improvement with HBOT, and the number needed to treat (NNT) to achieve one extra good outcome was 5 (95% CI 3 to 20). There was also an absolute improvement in average pure-tone audiometric threshold following HBOT (mean difference (MD) 15.6 dB greater with HBOT, 95% CI 1.5 to 29.8, P = 0.03). [NOTE: An improvement in hearing intensity of 10dB is a 10-fold increase because of the logarithmic relationship.] The significance of any improvement in tinnitus could not be assessed.There were no significant improvements in hearing or tinnitus reported for chronic presentation (six months) of ISSNHL and/or tinnitus. Authors concluded that for people with acute ISSNHL, the application of HBOT significantly improved hearing, but the clinical significance remains unclear. We could not assess the effect of HBOT on tinnitus by pooled analysis. In view of the modest number of patients, methodological shortcomings and poor reporting, this result should be interpreted cautiously. An appropriately powered trial is justified to define those patients (if any) who can be expected to derive most benefit from HBOT. This COCHRANE analysis found no evidence of a beneficial effect of HBOT on chronic ISSNHL or tinnitus and did not recommend the use of HBOT for this purpose. Authors found some evidence from 7 small trials of generally poor quality, that hearing may be improved in people with acute ISSNHL ,and possibly, that tinnitus may also be improved. This may only be true if HBOT is used within two weeks of the onset of problems. There is no evidence that HBOT can help people who have been deaf for some months. Further research is needed. The study design problems that result in a low recommendation include: small number of studies, modest number of patients, methodological variation (differing oxygen dosage and pressure), and reporting inadequacies.
Randomized controlled trials (RCTs)
- A 2018 RCT included 60 patients with severe to profound ISSNHL (=70 dB HL) and compared effectiveness of an oral steroid + intratympanic steroid injection (ITSI) group (control group) and an oral steroid + ITSI + HBOT group (study group). Authors concluded that the addition of HBOT to steroid combination therapy does not improve the average pure tone audiometry (PTA) values in severe to profound ISSNHL; however, it was associated with a better outcome at 500 Hz 1 month after treatment (p<0.05) and, at 1 kHz, word discrimination scores 3 months after treatment (p<0.05). The sum of complete and partial hearing recovery was significantly higher for the study group than for the control group.[9]
- A 2019 study was to investigate the efficacy and prognostic factors of hyperbaric oxygen therapy (HBOT) plus drug therapies in the treatment of sudden hearing loss.
Results Sixty-four patients with sudden hearing loss were enrolled, including 7 cases of low-frequency loss, 4 cases of high-frequency loss, 32 cases of flat loss, and 21 cases of complete hearing loss. After HBOT, there were 16 cases (25%) of complete recovery, 15 cases (23.43%) of partial recovery, 7 cases (10.93%) of slight improvement, and 26 cases (40.63%) of no improvement. The total effective rate was 59.37%. Twelve of 21 cases (57.14%) of complete hearing loss showed recovery. Multivariate logistic regression analysis showed that the start time of HBOT = 7 days from disease onset was independently associated with hearing recovery ( OR = 27.763, 95% CI [4.209, 183.115], p = .001). Conclusion Combined HBOT can improve the hearing impairment of sudden hearing loss. The early HBOT showed the most promising therapeutic effects, especially among patients with complete hearing loss.[10]
Prospective cohort studies
- A 2018 prospective cohort study from Egypt enrolled 22 patients with ISSNHL: 11 were medical therapy only and 11 included adjunctive HBOT. Details of the randomization were not provided, nor is there evidence of blinding of observers. HBOT was delivered at 2.0 ATA for 60 minutes of oxygen breathing daily for 20 days. After 30 days, the medical therapy group shows improvement of 18dB average. In the HBOT group, 5 patients showed total improvement and the other 6 showed improvement of 28dB. They concluded that addition of HBOT showed significant hearing improvement at 30 days.[11]
Retrospective studies
- In 2018, Xie and colleagues performed a retrospective study of 178 patients.[12] Overall, those receiving adjunctive HBOT showed a 37.1% recovery (19.7% complete recovery and 17.4% partial recovery compared to a cohort of medical therapy only. Poor prognostic indicators were greater time lapse between symptoms and starting HBOT, and those with more profound hearing loss at initial presentation. Inclusion criteria were similar to Hosokawa.[13] HBOT was delivered at 2.0ATA for 60 minutes of oxygen breathing twice daily for 10 days (20 treatments).
- A 2017 retrospective study of 167 cases of ISSNHL by Hosokawa and colleagues showed significant improvement and complete recovery in 32 patients with 45 patients showing modest improvement after HBOT compared with medical therapy alone. Two exclusion factors are noted. No patients under the age of 10 years were included, and there were no patients analyzed who had symptoms more then 30 days previously. HBOT dosage was 2 ATA for 60 minutes of oxygen breathing for 10 days (no breaks). When HBOT was started in less than 7 days after onset of symptoms, 63.2% improvement was noted. A steady and precipitous decline occurred after that. More than 8 days elapsing, gave a 43.9% improvement, almost 20% less than starting at least 1 day earlier.[13]
Case reports
- A 2017 case report of a 44 y/o female patient with sudden onset of unilateral hearing deterioration (left ear), sensation of aural fullness and loud tinnitus over a 48 hour period. The Patient was diagnosed with Unilateral Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL). She was admitted to the Department of Otolaryngology and began a treatment regimen of high-dose corticosteroids combined with adjunctive HBOT. HBOT was delivered once daily for 15 days, at a pressure of 2.5 ATA while breathing 100% oxygen, with a total bottom time (TBT) of 60 minutes. Authors concluded that the early implementation of pharmacotherapy and HBOT resulted in full recovery of hearing. Further systematic research is needed to determine the optimal protocol. Specifically, HBO treatment depth, TBT and number of treatments provided in relation to the onset of symptoms and the implementation of therapy.[14]
CATEGORY A CONTINUING EDUCATION CREDIT
This topic has been reviewed and approved by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT) for one (1) Category A Credit.
To claim the credit:
- 1. Read the topic
- 2. Answer the examination and course critique questions.
- Take the quiz via SurveyMonkey
- 3. Receive the certificate by e-mail. A passing score of 70% is required (please allow up to 8 business days for processing)
For more information on Category A continuing education credits see blog post "Hyperbaric Certification and Continuing Education for Technicians & Nurses"
REVISION UPDATES
| Date | Description |
| 3/3/23 | Added section 'Category A Continuing Education Credit' |
| 5/14/19 | Added sections 'Documentation' and 'Clinical Evidence and Recommendations' |
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