The Use of Hyperbaric Oxygen Therapy and Corticosteroid Therapy in Acute Acoustic Trauma: 15 Years' Experience at the Czech Military Health Service

Hyperbaric oxygen therapy and corticosteroids as combined treatment for acute acoustic trauma

PURPOSE

Acute acoustic trauma (AAT) is a sudden sensorineural hearing loss (SNHL) due to exposure to high intensity impulse noise. There are no acceptable treatment guidelines, although several studies showed steroids could be effective in restoring hearing levels. A recent report suggested that steroids combined with hyperbaric oxygen therapy (HBOT) are a superior regiment for AAT. The purpose of the current study is to investigate the effectiveness of steroids and HBOT for AAT treatment.

METHODS

the medical records 90 patients (118 ears) afflicted with AAT and treated with steroids and HBOT were retrospectively reviewed. Inclusion criteria were sensorineural hearing loss of at least 30 dB at the high frequency range (> 3,000 Hz) following exposure to intense sound. Patients who started treatment within 7 days were classified as "Early treatment" group whereas patients who started treatment ≥ 8 days after AAT were classified as "Late treatment".

RESULTS

The high frequency (3-8 kHz) Pure Tone Average (hPTA) of the entire study population (n = 118) was 40.26 ± 15.42 dB pretreatment vs. 24.99 ± 15.83 dB post treatment (Wilcoxon matched-pairs test, P < 0.0001). Pre-treatment hPTA was not statistically different between early and late study groups, 39.87 ± 16.00 vs. 40.86 ± 14.35 dB in the early vs. late group, respectively (ANOVA, F[3,232] = 22.574, P > 0.05). The post-treatment hPTA on the other hand, was significantly lower in the early vs. late treatment groups (21.93 ± 15.38 vs.31.19 ± 15.09 dB, respectively; ANOVA, F[3,232] = 22.574, P < 0.05).

CONCLUSION

Combination treatment with corticosteroids and HBOT is highly beneficial in improving hearing outcomes following AAT, when initiated within 7 days. This study was retrospectively registered on July 19th 2020 and assigned the identifier number NCT04482998.

Treatment of sudden sensorineural hearing loss with tinnitus with Fu subcutaneous needling: A case report

RATIONALE

Fu's subcutaneous needling (FSN) is a special acupuncture method that uses FSN to sweep the subcutaneous tissue around or adjacent to the limbs to disperse the pain. Sudden sensorineural hearing loss (SSHL) is a kind of otological emergency with sudden onset within 72 hours, with unilateral hearing loss, and hearing loss of ≥20 dB in 2 connected frequencies, and most of the patients have no obvious triggers. Most patients with SSHL are accompanied by tinnitus, vertigo, and nausea and vomiting.

PATIENT CONCERNS

The patient suffered from hearing loss with tinnitus. Although received relevant treatment, the hearing loss and tinnitus did not improve significantly.

DIAGNOSES

SSHL with tinnitus.

INTERVENTIONS

FSN treatment. A point 5 cm lateral to the point of tension and stiffness of the left trapezius muscle was selected on the affected back as the needle insertion point, and the condition of the neck muscles was improved through the FSN sweeping movement with neck reperfusion activities. The patient received treatment twice a week, and 4 weeks of treatment as a phase. At the end of each phase, a pure tone threshold audiometry, tinnitus evaluation scale Tinnitus Handicap Inventory assessment, and neck muscle palpation were performed.

OUTCOMES

The patient's hearing improved and the Tinnitus Handicap Inventory score decreased.

LESSONS

FSN has a good therapeutic effect on SSHL with tinnitus.

The Characteristics and Prognosis of Acute Hearing Loss in Military Personnel

Introduction: The military population is one of the high-risk groups for acute hearing loss. This retrospective study aims to examine acute acoustic trauma (AAT) and idiopathic sudden sensorineural hearing loss (ISSNHL) among military personnel. Materials and Methods: A total of 111 cases of acute hearing loss from a tertiary hospital between 2009 and 2021 were divided into AAT (53 cases) and ISSNHL (58 cases) groups. The time interval between trauma and treatment initiation, accompanying symptoms, and hearing thresholds before and after treatment were examined for all cases. Results: Two-thirds of the AAT group participants experienced damage to the left ear, and all individuals in this group presented with tinnitus at the time of trauma, but vertigo was less common in the AAT group than in the ISSNHL group. Hearing improvement after treatment was significant in both groups. An intergroup comparison of post-treatment hearing recovery revealed that prognosis was primarily determined by the initial severity of hearing loss rather than the underlying condition of AAT or ISSNHL. Conclusions: This finding emphasizes the importance of prompt and aggressive treatment in severe cases and the need for tailored strategies within military healthcare systems to improve hearing outcomes.

Recovery rate after acute acoustic trauma: a case series and meta-analysis

OBJECTIVE

Steroids given systemically, locally, or both are the mainstay of treatment for acute acoustic trauma (AAT). The overall recovery rate (full, partial, and none) is undetermined.

STUDY DESIGN

Original case series and systematic literature review.

SETTING

Case series of a tertiary referral center and a systematic literature review.

METHODS

Cases of AAT between 2012 and 2022 were retrospectively analyzed for demographics, acoustic trauma characteristics, treatment modality and delay and prognosis. This case series was added to the series identified by a systematic literature review. This review included "Medline" via "PubMed", "EMBASE", and "Google scholar". All series were pooled for meta-analysis defining prognosis following steroidal treatment for AAT patients.

RESULTS

The pooled analyses included 662 ears, out of which 250 underwent complete recovery of hearing (overall proportion = 0.2809, 95%confidence interval [CI] = 0.1611-0.4178). Any recovery was recorded for 477 ears (overall proportion = 0.7185, 95% CI = 0.5671-0.8493) and no recovery was documented for 185 ears (overall proportion = 0.2815, 95% CI = 0.1507-0.4329).

CONCLUSION

The rate of overall recovery for AAT is around 70%, and around 30% for full recovery when steroids are initiated within the first 2 weeks following the insult.

LEVEL OF EVIDENCE: 3

From sound waves to molecular and cellular mechanisms: Understanding noise‑induced hearing loss and pioneering preventive approaches (Review)

Noise-induced hearing loss (NIHL) is a significant and urgent global public health concern, arising from prolonged exposure to elevated levels of noise. This auditory impairment harms delicate inner ear structures, particularly the essential hair cells transmitting auditory signals to the brain. Recognized by the World Health Organization as a major contributor to worldwide hearing loss, NIHL requires a comprehensive examination of its molecular and cellular mechanisms. Animal models emerge as indispensable tools for unraveling these intricacies, allowing researchers to simulate and study the impact of noise exposure on auditory structures, shedding light on the interplay of oxidative stress, inflammation and immune responses-crucial factors in NIHL progression. The present review focuses on elucidating the molecular mechanisms of NIHL, with a specific emphasis on findings derived from animal models, alongside the exploration of thorough preventive strategies, including protective measures and probing potential interventions. Understanding the molecular underpinnings not only provides insight into targeted treatment approaches, but also unlocks pathways for exploring and implementing preventive actions. This approach not only deepens the current comprehension of NIHL, but also has the potential to influence the shaping of public health policies, offering a nuanced perspective on this prevalent auditory disorder.

Efficacy of hyperbaric oxygen therapy in treating sudden sensorineural hearing loss: an umbrella review

Introduction

Our objective was to explore the efficacy of hyperbaric oxygen in the treatment of sudden sensorineural hearing loss by conducting an umbrella review of all existing evidence.

Methods

We conducted an umbrella review, searching for related articles in the PubMed, Web of Science, Embase, and Scopus databases. The search period covered from the inception of each database until April 2024. We extracted authors, country of publication, time of publication, number of included studies and participants, interventions, summary of results, P-values, I 2, relative risk (95% CI), and outcome measures. The methodological quality, evidence quality, and overlap rate of the included articles were assessed using AMSTAR 2, GRADE, and OVErviews (GROOVE).

Results

Methodological quality was assessed using AMSTAR 2. Of the nine included articles, two were assessed as "high," three as "moderate," two as "low," and the remaining two as "very low." The quality of evidence was assessed using the GRADE system. It was found that the quality of evidence in most of the studies was unsatisfactory. It was found that there was a slight overlap among the included articles. Six studies reported positive results (OR 1.37; 95% CI, 1.17-1.61; P = 0.04), with high heterogeneity observed (I 2 = 63%). Egger's test indicated bias (P = 0.000101). Three studies reported negative results (MD 1.49; 95% CI, -0.32 to 3.29; P = 0.43; I 2 = 0%), with no significant bias detected (P = 0.106) according to Egger's test.

Conclusion

HBO therapy is shown to be an effective treatment for SSNHL with fewer side effects. However, the methodological quality and evidence of the systematic reviews and meta-analysis included in this study were generally low. Therefore, more high-quality, large-scale, multi-center randomized controlled trials are needed in the future to verify the efficacy of HBO therapy for SSNHL.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier [CRD42024523651].

Long-Term Hearing Loss after Acute Acoustic Trauma in the French Military: A Retrospective Study

INTRODUCTION

Acute acoustic trauma (AAT) is characterized by cochlea-vestibular signs following intense noise exposure, often caused by impulse noise. French military faces a high risk of AAT because of the use of weapons with peak sound levels exceeding 150 dB. Hearing loss (HL) resulting from AAT can have a significant impact on quality of life and operational capacity. The aim of this study was to assess the prevalence of long-term hearing impairment after AAT.

MATERIALS AND METHODS

The study involved a retrospective review of computer-based patient records from four military medical centers in Northeast France between January 2016 and December 2021. The inclusion criteria required the presence of cochlea-vestibular signs following impulse acoustic exposure and the absence of other causes. Sociodemographic and clinical data were collected, including audiometric data before and after exposure. The primary end point was the presence of a threshold elevation greater than 10 dB between reference and late audiograms.

RESULTS

A total of 419 patients were included in the analysis, with a majority of males (n = 419; 84.7%) and a mean age of 23.6 yrs. The most common causative agent was the 5.56-mm assault rifle (n = 327; 78.0%). Tinnitus was the most frequent symptom (n = 366; 87.4%), followed by hypoacusis (n = 147; 35.1%) and earache (n = 89; 21.2%). The initial audiograms showed no HL in 31.0% of cases, while the mean deficit across all frequencies was 15.4 dB. All patients received corticosteroid therapy, with a mean duration of 6.0 d. Late audiograms conducted at an average interval of 448.0 d after AAT revealed a prevalence of long-term HL exceeding 20%. Higher doses of corticosteroid therapy (>1 mg/kg) were associated with a reduced frequency of long-term HL.

CONCLUSIONS

This study highlights the prevalence of long-term hearing impairment after AAT in the French military. The findings emphasize the importance of preventive measures, including proper use of hearing protection devices, and the need for timely diagnosis and treatment. Further research is warranted to explore gender susceptibility to AAT and evaluate the impact of different weapons on AAT characteristics. The study also underscores the potential benefits of higher doses of corticosteroid therapy in reducing the risk of long-term hearing impairment. Overall, the findings contribute to a better understanding of AAT and can inform strategies for its prevention and management in military settings.

Acoustic differences in tinnitus between noise-induced and non-noise-induced hearing loss

BACKGROUND

Tinnitus, the perception of sound without external stimuli, varies across hearing loss types. The present study compared the acoustic characteristics of tinnitus in patients with noise-induced hearing loss (NIHL) and in those with hearing loss unrelated to noise exposure.

OBJECTIVE

This study compared the acoustic characteristics of tinnitus in patients with noise-induced and non-noise-induced hearing loss.

METHODS

A total of 403 patients with tinnitus were divided into those with noise-induced and non-noise-induced hearing loss. Patients were evaluated by pure tone audiometry (PTA), tinnitogram, transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), and auditory brainstem evoked response (ABR) tests.

RESULTS

Patients with NIHL exhibited significantly higher hearing thresholds across all frequencies (125-8000 Hz) (p < .05) and reported significantly higher tinnitus intensity (p < .05). Otoacoustic emission tests showed that response rates were significantly lower (p < .05), and ABR tests found that latency periods were significantly more prolonged (p < .05), in patients with NIHL.

CONCLUSIONS

Tinnitus differs acoustically between patients with NIHL and those with non-noise-induced hearing loss, with specific patterns of intensity and auditory responses. These findings emphasize the need for tailoring the management of tinnitus according to the underlying type of hearing loss.