Inner and middle ear hyperbaric oxygen-induced barotrauma

Effect of self-acupressure on middle ear barotrauma associated with hyperbaric oxygen therapy: A nonrandomized clinical trial

BACKGROUND

In hyperbaric oxygen therapy (HBOT), a patient is exposed to pure oxygen in a chamber. While HBOT is a long-standing and well-established treatment for a wide variety of medical conditions, one of the main complications is middle ear barotrauma (MEB), which can lead to complaints of ear discomfort, stuffiness or fullness in the ear, and difficulties in equalizing ear pressure. The aim of this study is to evaluate the efficacy of self-acupressure in preventing and reducing the degree of MEB associated with HBOT.

METHODS

This is a prospective nonrandomized controlled study. A sample of 152 participants will be assigned to 2 groups in a 1:1 ratio. The participants in the control group will receive conventional Valsalva and Toynbee maneuvers, while those in the experimental group will be given additional self-acupressure therapy. The acupoints used will be TE17 (Yifeng), TE21 (Ermen), SI19 (Tinggong), and GB2 (Tinghui). The Modified Teed Classification, symptoms of MEB, and overall ear discomfort levels will be assessed. Data will be analyzed using the Chi-Squared test or t test.

OBJECTIVES

This study aims to evaluate the efficacy of self-acupressure for preventing and reducing the degree of MEB associated with HBOT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04311437. Registered on 17 March, 2020.

Effect of antiplatelet and/or anticoagulation medication on the risk of tympanic barotrauma in hyperbaric oxygen treatment patients, and development of a predictive model

INTRODUCTION

Middle ear barotrauma (MEBt) is a common side effect of hyperbaric oxygen treatment (HBOT) and can result in pain, hearing loss, tinnitus and otorrhagia. The use of antiplatelet/anticoagulant drugs is thought to increase the risk and severity of MEBt during HBOT.

METHODS

Single centre, retrospective observational cohort study of all patients treated with HBOT over a 4-year period (between 01 January 2015 to 31 December 2018) looking at the incidence of MEBt and the concurrent use of antiplatelet and/or anticoagulant drugs. MEBt was assessed by direct otoscopy of the tympanic membrane post-HBOT and scored using the modified Teed classification. Multivariate modelling assessed the relationship between antiplatelet and/or anticoagulation drug use, age, sex, and MEBt during HBOT.

RESULTS

There was no evidence that antiplatelet and/or anticoagulation drugs increase the risk of tympanic barotrauma in HBOT patients. The prevalence of MEBt was higher in female patients than in males (χ2 P = 0.004), and increased with age (χ2 P = 0.048). No MEBt was recorded in patients undergoing recompression therapy for decompression sickness or cerebral arterial gas embolism.

CONCLUSIONS

In this retrospective single-centre study, antiplatelet and/or anticoagulation drugs did not affect the risk of MEBt, but both age and sex did, with greater prevalence of MEBt among older patients and females compared with younger patients and males. A predictive model, requiring further validation, may be helpful in assessing the likelihood of MEBt in patients undergoing HBOT.

Comparison of Therapeutic Results with/without Additional Hyperbaric Oxygen Therapy in Idiopathic Sudden Sensorineural Hearing Loss: A Randomized Prospective Study

OBJECTIVE

To assess the efficacy of the combination of hyperbaric oxygen (HBO) and pharmacological treatment in patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and define patients amenable for HBO therapy.

METHODS

Prospective, randomized, trial involving 136 cases with unilateral ISSNHL that were randomly divided into 2 groups: the pharmacological treatment (P) group and HBO + pharmacological treatment (HBO+P) group, which received additional HBO for 14 days besides the pharmacological treatments. Pure tone audiometry gain larger than 15 dBHL was defined as success, and the success rate of each group was calculated.

RESULTS

The overall success rate of the HBO+P group and the P group is 60.6% (40/66) and 42.9% (30/70), respectively (p < 0.05). Furthermore, patients with mild-moderate baseline hearing loss, aged ≤50 years, receiving treatment in ≤14 days, or without accompanied dizziness/vertigo in the HBO+P group had higher success rate than the P group (p < 0.05).

CONCLUSIONS

HBO combined with pharmacological treatments leads to better hearing recovery than pharmacological treatments alone.

Identifying eustachian tube dysfunction prior to hyperbaric oxygen therapy: Who is at risk for intolerance?

PURPOSE

Determine whether specific risk factors, symptoms and clinical examination findings are associated with hyperbaric oxygen therapy (HBOT) intolerance and subsequent tympanotomy tube placement.

MATERIALS AND METHODS

A retrospective case series with chart review was conducted from 2007 to 2016 of patients undergoing HBOT clearance at a tertiary care university hospital in an urban city. Eighty-one (n=81) patient charts were reviewed for risk factors, symptoms and clinical examination findings related to HBOT eustachian tube dysfunction and middle ear barotrauma. Relative risk was calculated for each variable to determine risk for HBOT intolerance and need for tympanotomy tube placement. Risk factor, symptom, physical examination and HBOT complication-susceptibility scores were calculated for each patient.

RESULTS

Mean risk factor, clinical and HBOT complication-susceptibility scores were significantly higher in patients who did not tolerate HBOT compared to patients who tolerated HBOT. Patients reporting a history of otitis media, tinnitus, and prior ear surgery were at a higher risk for HBOT intolerance. Patients reporting a history of pressure intolerance and prior ear surgery were more likely to undergo tympanotomy tube placement. Patients noted to have otologic findings prior to HBOT were at a higher risk for both HBOT intolerance and tympanotomy tube placement.

CONCLUSIONS

A thorough otolaryngological evaluation can potentially predict and identify patients at risk for HBOT intolerance and tympanotomy tube placement.

Hyperbaric Oxygen Therapy: Side Effects Defined and Quantified

Significance: Hyperbaric oxygen therapy (HBOT) is an important advanced therapy in the treatment of problem wounds, including diabetic foot ulcers and late effect radiation injury. HBOT remains among the safest therapies used today. Nonetheless, there are side effects associated with HBOT. It is important for providers to be able to identify, understand, and quantify these side effects for prevention, management, and informed consent. Recent Advances: The past two decades have seen significant advancements in our understanding of the underlying mechanisms of HBOT. This has led to a better understanding of the underlying reason for clinical benefit. It has also led to a better understanding of its side effects. Moreover, more recent literature allows for better quantification of these side effects. This review will highlight these side effects. Critical Issues: Wound healing in the case of problem nonhealing wounds requires the use of various advanced treatment modalities, including HBOT. HBOT has been shown to significantly improve healing rates in certain problem wounds, including advanced diabetic foot ulcers and late effect radiation injury. It is provided in a variety of clinical settings by providers with varying levels of expertise. It is important for those providing this therapy to understand the potential side effects. Future Directions: Research in HBOT has led to significant advancements in the area of wound healing. At the same time, there remains a variety of treatment protocols used at different institutions. It is important to quantify risk and benefit at different treatment pressures and times to better standardize treatment and improve patient care.

Otological complications associated with hyperbaric oxygen therapy

The objective of the present study was to clarify the features of otological complications for hyperbaric oxygen therapy (HBOT) and the risk factors for these complications. We enrolled 1115 patients (776 males and 339 females; age 5-89 years) who underwent HBOT. All otological symptoms experienced during HBOT sessions were evaluated, and risk factors were analysed using multivariate logistic regression analysis. Otoscopic findings and interventions for otological complications were assessed in 58 symptomatic patients who visited the Otolaryngology Department. Otological symptoms were experienced by 165 (14.8 %) of the 1115 patients. The multivariate logistic regression analysis identified ages of >60 years and female sex as independent risk factors, whereas patients with sports injuries were at lower risk than those with other primary diseases, except for severe infectious disease. Eighty-two patients (49.7 %) suffered from symptoms at the first HBOT session. The most prevalent symptoms were otalgia (157/165), followed by ear fullness (13/165), hearing loss (12/165) and tinnitus (3/165). One patient experienced vertigo and deterioration of the bone-conduction pure-tone thresholds, suggesting inner ear barotrauma. In 116 ears of the 58 symptomatic patients, abnormal otoscopic findings were recognized in 58 ears (50.0 %). Twenty-seven of the 58 ears required myringotomy or tube insertion, and HBOT was stopped in eight ears in four patients. Of the remaining 58 ears with normal otoscopic findings, 51 received no treatment. Physicians should be aware of both middle and inner ear barotrauma as potential complications of HBOT.

Adjunctive hyperbaric oxygen for necrotizing fasciitis

BACKGROUND

Hyperbaric oxygen therapy (HBOT) involves the therapeutic administration of 100% oxygen in a pressure chamber at pressures above one atmosphere absolute. This therapy has been used as an adjunct to surgery and antibiotics in the treatment of patients with necrotizing fasciitis with the aim of reducing morbidity and mortality.

OBJECTIVES

To review the evidence concerning the use of HBOT as an adjunctive treatment for patients with necrotizing fasciitis (NF). Specifically, we wish to address the following questions.1. Does administration of HBOT reduce mortality or morbidity associated with NF?2. What adverse effects are associated with use of HBOT in the treatment of individuals with NF?

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE Ovid (1966 to September 2014); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) Ovid (1982 to September 2014); EMBASE Ovid (1980 to September 2014); and the Database of Randomised Controlled Trials in Hyperbaric Medicine (DORCTHIM, M Bennett) (from inception to September 2014). In addition, we performed a systematic search of specific hyperbaric literature sources. This included handsearching of relevant hyperbaric textbooks; hyperbaric journals (Hyperbaric Medicine Review, South Pacific Underwater Medicine Society Journal, European Journal of Underwater and Hyperbaric Medicine, Aviation Space and Environmental Medicine Journal); and conference proceedings of the major hyperbaric societies (Undersea and Hyperbaric Medical Society, South Pacific Underwater Medicine Society, European Underwater and Baromedical Society, International Congress of Hyperbaric Medicine).

SELECTION CRITERIA

We included all randomized and pseudo-randomized trials (trials in which an attempt at randomization has been made but the method was inappropriate, for example, alternate allocation) that compared the effects of HBOT with the effects of no HBOT (no treatment or sham) in the treatment of children and adults with necrotizing fasciitis.

DATA COLLECTION AND ANALYSIS

We planned independent data collection by two review authors using standardized forms.

MAIN RESULTS

We found no trials that met the inclusion criteria.

AUTHORS' CONCLUSIONS

This systematic review failed to locate relevant clinical evidence to support or refute the effectiveness of HBOT in the management of necrotizing fasciitis. Good quality clinical trials are needed to define the role, if any, of HBOT in the treatment of individuals with necrotizing fasciitis.

Update on middle ear barotrauma after hyperbaric oxygen therapy-insights on pathophysiology

Introduction Middle ear barotrauma is the most common side effect of hyperbaric oxygen therapy. Knowledge and understanding of its pathophysiology are crucial for an accurate diagnosis and proper decision making about treatment and prevention.

Objective Describe up-to-date information on pathophysiology of middle ear barotrauma after hyperbaric oxygen therapy considering the physiology of pressure variation of the middle ear.

Data Synthesis Middle ear barotrauma occurs especially during the compression phase of hyperbaric oxygen therapy. The hyperoxic environment in hyperbaric oxygen therapy leads to ventilatory dysfunction of the eustachian tube, especially in monoplace chambers, where the patients are pressurized with 100% O₂, favoring middle ear barotrauma.

Conclusion The eustachian tube, the tympanic cavity, and mastoid work together in a neural controlled feedback system in which various mechanisms concur for middle ear pressure regulation.

New paradigms in the pathogenesis of otitis media in children

Acute otitis media (AOM) is a multifactorial disease with a significant socioeconomic impact. The pathogenesis of AOM is attributed to a variety of well-established internal and extrinsic factors. Recent evidence strongly points to bacterial biofilm formation as an important contributor to this disease entity. The nasopharynx is a likely reservoir for infection with subsequent seeding of pathogens to the middle ear via planktonic shedding. Various modalities have been used to directly detect biofilm formation in the middle ear mucosa of children with AOM. Further insights into this disease may lead to new strategies for prevention and treatment.

A novel technique of otic barotrauma management using modified intravenous cannulae

This article provides the first detailed description and systematic evaluation of the management of otic barotrauma using modified intravenous cannulae. A 24-gauge IC cannula was modified as a tool for tympanostomy tube placement and middle ear ventilation. The medical records of 271 ears of 156 adult patients (median age 49 years) who underwent this procedure were reviewed retrospectively. Hundred and ninty-one tubes were placed for otalgia because of hyperbaric oxygen therapy, 58 tubes were inserted for air travel prophylaxis and 22 tubes were placed for management of otic barotrauma post-flight. All the patients who had this procedure for prophylaxis experienced regular otic barotrauma symptoms during air travel prior to tube placement. All patients were reviewed 6 weeks (range 2-9 weeks) post-procedure. This technique of otic barotrauma management worked effectively in 99 % of treated patients. On follow-up, 88 % of tubes were found to be extruded and non-extruded tubes were removed in clinic without any anaesthesia. 99.6 % of tympanic membrane had healed completely and spontaneously without sequelae. Given the safety, effectiveness, low risk of complications associated with this novel tympanostomy technique, it provided a simple yet effective therapeutic option for the management of otic barotrauma. Finally, this technique can be easily applied in all health settings as it only requires medical supplies readily available in hospitals, therefore there is no additional cost.

Clinical and tympanometric findings in repeated recreational scuba diving

BACKGROUND

Due to the condition known as middle ear squeeze, scuba diving has become one of the main causes of barotrauma, and the acute form of this condition has been relatively well established. However, there are few reports available on clinical or laboratory findings in divers who practise repeated diving. The objective of the present study was to assess the otological effects of repeated dives.

METHOD

This was an observational study conducted on 19 recreational scuba divers, considered to be experienced divers according to the criteria established by the Professional Association of Dive Instructors (PADI). These divers undertook four dives per day on five consecutive days, and their tympanic membranes were assessed using tympanometry and otoscopy. Data were analysed using the chi(2)-test for trend. The level of statistical significance was set at p<0.05 in all analyses.

RESULTS

The findings suggest that multiple scuba dives over a short period of time cause damage to the structures of the ear, as evidenced by the tympanometric and otoscopic findings, which revealed cumulative effects of pressure against the tympanic membrane and within the middle ear. This condition was not observed when surface intervals exceeded 11h.

CONCLUSIONS

The results suggest that extending surface intervals may offer protection against middle ear barotrauma in recreational scuba diving.

Different reactions of human nasal and Eustachian tube mucosa after hyperbaric oxygen exposure: a pilot study

Impairment of Eustachian tube function has been observed after hyperbaric oxygen treatment as well as after diving on oxygen used as breathing gas. The aim of the present study was to evaluate the influence of hyperbaric oxygen exposure on Eustachian tube ventilatory function and airflow characteristics of the nose. Six police task force divers performing two consecutive dives within a regular training schedule on oxygen were examined. Middle ear impedance, and nasal airflow velocities before and after diving as well as on the morning after the dive day were measured. Middle ear impedance decreased overnight in comparison to pre-dive values (P = 0.027) as well as compared to the value after the first dive (P = 0.032). Rhinoflowmetry did not reveal any changes of nasal airflow velocities related to the dives. Furthermore, no association between middle ear impedance and nasal airflow velocities was found. An impairment of Eustachian tube ventilatory function was obtained after hyperbaric oxygen exposure during dives employing oxygen as breathing gas. This impairment, however, was not associated with altered airflow characteristics of divers' noses. Thus, it seems unlikely that hyperbaric oxygen exerts an effect on the nasal mucosa similar to that on the Eustachian tube mucosa.

Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

Background

Hyperbaric oxygen therapy (HBOT) is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS), is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs.

Results

Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS) was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model.

Conclusions

The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

Middle Ear Barotrauma with Hyperbaric Oxygen Therapy: Incidence and the Predictive Value of the Nine-step Inflation/Deflation Test and Otoscopy

We conducted a prospective study to determine the incidence of middle ear barotrauma in patients who were undergoing hyperbaric oxygen therapy (HBOT). We also investigated the value of the nine-step inflation/deflation test and otoscopic findings before and immediately after the initial HBOT session in predicting barotrauma in an attempt to establish some criteria for prophylaxis. The study was conducted on 36 ears of 18 adults who had no history of eustachian tube dysfunction. Patients were being treated with HBOT for sudden hearingloss, wound-healing complications, or complications of diabetes. After 7 days of HBOT, barotrauma was seen in 12 of the 18 patients (66.7%) and in 18 of the 36 ears (50.0%). The nine-step inflation/deflation tests, which were performed before and immediately after the initial HBOT session, were not predictive of barotrauma (p = 0.095 before and p = 0.099 after). However, otoscopic findings obtained immediately after the first session of HBOT were predictive of barotrauma, with a sensitivity and specificity of 83 and 100%, respectively. We conclude that patients with even minor positive pathologic findings on otoscopy immediately following HBOT are at increased risk of middle ear barotrauma if HBOT is to be continued without prophylaxis.

[Hyperbaric oxygenation: characteristics of intensive care and emergency therapy]

Hyperbaric oxygenation (HBO) is a decisive component of a comprehensive interdisciplinary intensive care therapy for numerous disorders, such as gas embolism, severe decompression illness or carbon monoxide (CO) intoxication. However, barochambers with 24 h accessibility are often not readily available, thus, requiring an interhospital transport of critically ill patients. In order to minimise additional risks, a skilled transportation team should be involved. Furthermore, the specific physical and physiological features of HBO require that the transportation personnel must be trained adequately. Specific characteristics of the interhospital transfer of HBO patients are described as well as adverse effects and their specific therapy.

Cochlear implantation and meningitis

OBJECTIVE

Study clinical presentation, diagnosis and treatment of cochlear implant patients diagnosed with bacterial meningitis.

BACKGROUND

Cochlear implantation in children is necessary for the optimal development of speech in the developing child diagnosed with profound sensorineural hearing loss. Approximately 60,000 devices have been inserted in adults and children worldwide to date.

SETTING

The Department of Pediatric Otolaryngology of a tertiary care children's hospital.

METHODS

All patients undergoing cochlear implantation from April 1997 were identified. Patients diagnosed with bacterial meningitis after implantation were selected for study.

RESULTS

Of 30 children, two developed bacterial meningitis after cochlear implantation. One patient developed Streptococcus pneumoniae meningitis. One patient developed nontypable Haemophilus influenzae bacterial meningitis. Both patients made a complete recovery.

CONCLUSIONS

Prompt diagnosis and treatment of meningitis is essential to optimize outcome.

Adjunctive hyperbaric oxygen in irradiated patients requiring dental extractions: outcomes and complications

PURPOSE

This study assessed complications of hyperbaric oxygen (HBO) therapy, potential predictors of poor outcome, and treatment outcomes in irradiated patients undergoing dental extractions.

PATIENTS AND METHODS

This was a prospective, descriptive study of 40 consecutive patients treated with HBO before and after dental extractions in an irradiated field. All patients had radiation caries; none had osteoradionecrosis (ORN). All were prescribed a protocol of 20 pre-extraction and 10 postextraction HBO treatments at 2.4 ATA for 90 minutes. Potential risk factors for poor healing and risk factors for complications were identified. All complications were recorded. Extraction site healing was evaluated at the conclusion of HBO therapy, at 1 month, and 1 year later.

RESULTS

There were no serious complications. There was no correlation between preidentified risk factors and poor healing. At 1 year, 98.5% of all extraction sites were healed. Patients who did not heal were an average of 8 years since radiation, compared with 3.3 years for those who healed (P <.001).

CONCLUSION

Use of HBO is associated with a very low incidence of ORN at 1-year follow-up. However, the time since radiation has a positive correlation with risk for ORN.

Can Eustachian Tube Ventilatory Function Impairment After Oxygen Diving Be Influenced by Application of Free Radical Scavenger Vitamins C and E?

OBJECTIVES/HYPOTHESIS

To evaluate the influence of free radical scavenger vitamins C and E on eustachian tube ventilatory function changes related to oxygen dives.

STUDY DESIGN

Prospective, randomized, double-blind, placebo-controlled study of middle ear impedance changes of oxygen divers being orally treated with free radical scavenger vitamins C and E.

METHODS

Fifteen divers were allocated to two groups. Before diving on oxygen on consecutive days (days 1 and 2), divers in group 1 took a daily dose of 1 g ascorbic acid and 600 International Units d-alpha-tocopherol and divers in group 2 were given placebo. Before diving and 2 and 24 hours after diving on days 1 and 2, middle ear impedance was measured.

RESULTS

Impedance decreased overnight after dive 1 (P =.04) but not after dive 2 (P =.31). No impedance differences were found between groups after the dive on day 1 (P =.83). Twenty-four hours after the dive on day 1 and after the dive on day 2, impedance values in both groups were different (P =.02 vs. P =.07), emphasizing slightly more negative pressures in the vitamin group.

CONCLUSION

Vitamins C and E did not reduce eustachian tube ventilatory function impairment overnight after the dive on day 1, suggesting no evidence of free radical-mediated toxicity affecting the eustachian tube or middle ear mucosa. Repetitive oxygen dives may cause tissue adaptation suggesting other than antioxidant defense mechanisms.

Inner ear barotrauma after stapedectomy in the guinea pig

OBJECTIVE

The safety of scuba diving after stapedectomy is controversial. Stapedectomy is thought to predispose to inner ear barotrauma (e.g., perilymph fistula); however, many individuals continue to scuba dive following stapedectomy without ill effects. The purpose of this study was to evaluate the cochlear effects of barotrauma, similar to that experienced with scuba diving, on inner ears previously treated with stapedectomy.

STUDY DESIGN

Prospective, controlled.

METHODS

Sixteen Hartley albino guinea pigs underwent unilateral total stapedectomy followed by hyperbaric dives on 5 consecutive days, beginning 3 weeks after stapedectomy. Cochlear effects were determined using click and tone-pip evoked electrocochleographic thresholds and cochlear hair cell counts.

RESULTS

Mean auditory thresholds increased by 29 dB after stapedectomy (P < .001), then remained stable thereafter. Mean thresholds in both the operated and control ears did not change with hyperbaric dives. Evidence of middle ear barotrauma (e.g., hemorrhage or tympanic membrane perforation) was observed in eight poststapedectomy ears and five control ears, but none demonstrated significant threshold elevation greater than or equal to 10 dB. Hair cell counts were not different between operated and control ears.

CONCLUSIONS

Stapedectomy does not appear to predispose to cochlear sequelae in the guinea pig model of diving-related barotrauma.

Classification of otitis media and surgical principles

Otitis media is an important disease of children and adults and is caused by multiple interrelated factors, including infection, eustachian tube dysfunction, allergy, and barotrauma. This article includes a pertinent review of the literature regarding otitis media. The pathogenesis, classification, and treatment of otitis media in children and adults are also reviewed in this article. Additionally, therapy is discussed with emphasis on the surgical options appropriate at each stage.