Breath-Hold Diving Injuries - A Primer for Medical Providers.

ABSTRACT: Breath-hold divers, also known as freedivers, are at risk of specific injuries that are unique from those of surface swimmers and compressed air divers. Using peer-reviewed scientific research and expert opinion, we created a guide for medical providers managing breath-hold diving injuries in the field. Hypoxia induced by prolonged apnea and increased oxygen uptake can result in an impaired mental state that can manifest as involuntary movements or full loss of consciousness. Negative pressure barotrauma secondary to airspace collapse can lead to edema and/or hemorrhage. Positive pressure barotrauma secondary to overexpansion of airspaces can result in gas embolism or air entry into tissues and organs. Inert gas loading into tissues from prolonged deep dives or repetitive shallow dives with short surface intervals can lead to decompression sickness. Inert gas narcosis at depth is commonly described as an altered state similar to that experienced by compressed air divers. Asymptomatic cardiac arrhythmias are common during apnea, normally reversing shortly after normal ventilation resumes. The methods of glossopharyngeal breathing (insufflation and exsufflation) can add to the risk of pulmonary overinflation barotrauma or loss of consciousness from decreased cardiac preload. This guide also includes information for medical providers who are tasked with providing medical support at an organized breath-hold diving event with a list of suggested equipment to facilitate diagnosis and treatment outside of the hospital setting.

Recommendations on scuba diving in Birt-Hogg-Dubé syndrome.

INTRODUCTION: Although very uncommon, severe injury and death can occur during scuba diving. One of the main causes of scuba diving fatalities is pulmonary barotrauma due to significant changes in ambient pressure. Pathology of the lung parenchyma, such as cystic lesions, might increase the risk of pulmonary barotrauma. AREAS COVERED: Birt-Hogg-Dubé syndrome (BHD), caused by pathogenic variants in the FLCN gene, is characterized by skin fibrofolliculomas, an increased risk of renal cell carcinoma, multiple lung cysts and spontaneous pneumothorax. Given the pulmonary involvement, in some countries patients with BHD are generally recommended to avoid scuba diving, although evidence-based guidelines are lacking. We aim to provide recommendations on scuba diving for patients with BHD, based on a survey of literature on pulmonary cysts and pulmonary barotrauma in scuba diving. EXPERT OPINION: In our opinion, although the absolute risks are likely to be low, caution is warranted. Given the relative paucity of literature and the potential fatal outcome, patients with BHD with a strong desire for scuba diving should be informed of the potential risks in a personal assessment. If available a diving physician should be consulted, and a low radiation dose chest computed tomography (CT)-scan to assess pulmonary lesions could be considered.

Diagnosis and Management of Barosinusitis: A Systematic Review.

OBJECTIVE: To perform a systematic review to investigate the common presenting symptoms of barosinusitis, the incidence of those findings, the methods for diagnosis, as well as the medical and surgical treatment options. METHODS: A review of PubMed/MEDLINE, EMBASE, and Cochrane Library for articles published between 1967 and 2020 was conducted with the following search term: aerosinusitis OR "sinus squeeze" OR barosinusitis OR (barotrauma AND sinusitis) OR (barotrauma AND rhinosinusitis). Twenty-seven articles encompassing 232 patients met inclusion criteria and were queried for demographics, etiology, presentation, and medical and surgical treatments. RESULTS: Mean age of patients was 33.3 years, where 21.7% were females and 78.3% were males. Causes of barotrauma include diving (57.3%), airplane descent (26.7%), and general anesthesia (0.4%). The most common presentations were frontal pain (44.0%), epistaxis (25.4%), and maxillary pain (10.3%). Most patients received topical steroids (44.0%), oral steroids (28.4%), decongestants (20.7%), and antibiotics (15.5%). For surgical treatment, most patients received functional endoscopic sinus surgery (FESS) (49.6%). Adjunctive surgeries include middle meatal or maxillary antrostomy (20.7%), septoplasty (15.5%), and turbinate surgery (9.1%). The most efficacious medical treatments are as follows: 63.6% success rate with oral steroids (66 treated), 50.0% success rate with topical steroids (102 treated), and 50.0% success rate analgesics (10 treated). For surgical treatments received by greater than 10% of the sample, the most efficacious was FESS (91.5% success rate, 108 treated). CONCLUSION: Oral and topical steroids should be first line therapies. If refractory, then functional endoscopic sinus surgery is an effective treatment.

"The Spiked Helmet sign": A harbinger of impending barotrauma.

The 'spiked helmet sign' (SHS) is an electrocardiographic finding associated with critical illness and a high risk of death; It is likened to ST-elevation, leading to harmful coronary imaging despite lack of apparent myocardial infarction. We describe the case of SHS secondary to high ventilation pressures in the setting of Acute Respiratory Distress Syndrome (ARDS) in a critically ill patient who subsequently developed barotrauma.

Middle Ear Barotrauma among Licensed Para-pilots of a Metropolitan City: A Descriptive Cross-sectional Study.

Introduction: Middle ear barotrauma is a tissue injury to the ear secondary to inadequate pressure equalisation between the middle ear and the external environment. Paragliding, though an exciting sport, has its own risks and hazards. Para-pilots experience a variety of ear-related symptoms due to pressure discrepancies between the middle ear and ambient air. Middle ear barotrauma amongst para-pilots is a common yet neglected problem. The aim of this study was to find the prevalence of middle ear barotrauma among licensed para-pilots of a metropolitan city. Methods: A descriptive cross-sectional study was conducted amongst para-pilots practising in different paragliding companies in a metropolitan city. The study was conducted from 10th October, 2021 to 22nd October, 2021 after getting ethical approval from the Institutional Review Committee (Reference number: 0410202109/2021). A sample size of 76 participants was taken using convenience sampling technique. Data was collected from participants after performing an otoscope examination. The data were entered into Microsoft Excel version 2016 and analysed using the Statistical Package for the Social Science Version 22.0. Point estimate at a 95% Confidence Interval was calculated along with frequency and proportion for binary data and mean and standard deviation for continuous data. Results: Out of 76 participants, the prevalence of middle ear barotrauma was 10 (13.2%) (5.58-20.81 at 95% Confidence Interval). Conclusions: The prevalence of middle ear barotrauma was similar to other studies done in similar settings. Keywords: barotrauma; eustachian tube; Nepal; pilots.

Dysbarism: An Overview of an Unusual Medical Emergency.

Dysbarism is a general term which includes the signs and symptoms that can manifest when the body is subject to an increase or a decrease in the atmospheric pressure which occurs either at a rate or duration exceeding the capacity of the body to adapt safely. In the following review, we take dysbarisms into account for our analysis. Starting from the underlying physical laws, we will deal with the pathologies that can develop in the most frequently affected areas of the body, as the atmospheric pressure varies when acclimatization fails. Manifestations of dysbarism range from itching and minor pain to neurological symptoms, cardiac collapse, and death. Overall, four clinical pictures can occur: decompression illness, barotrauma, inert gas narcosis, and oxygen toxicity. We will then review the clinical manifestations and illustrate some hints of therapy. We will first introduce the two forms of decompression sickness. In the next part, we will review the barotrauma, compression, and decompression. The last three parts will be dedicated to gas embolism, inert gas narcosis, and oxygen toxicity. Such an approach is critical for the effective treatment of patients in a hostile environment, or treatment in the emergency room after exposure to extreme physical or environmental factors.

Inner ear barotrauma and inner ear decompression sickness: a systematic review on differential diagnostics.

INTRODUCTION: Inner ear barotrauma (IEBt) and inner ear decompression sickness (IEDCS) are the two dysbaric inner ear injuries associated with diving. Both conditions manifest as cochleovestibular symptoms, causing difficulties in differential diagnosis and possibly delaying (or leading to inappropriate) treatment. METHODS: This was a systematic review of IEBt and IEDCS cases aiming to define diving and clinical variables that help differentiate these conditions. The search strategy consisted of a preliminary search, followed by a systematic search covering three databases (PubMed, Medline, Scopus). Studies were included when published in English and adequately reporting one or more IEBt or IEDCS patients in diving. Concerns regarding missing and duplicate data were minimised by contacting original authors when necessary. RESULTS: In total, 25 studies with IEBt patients (n = 183) and 18 studies with IEDCS patients (n = 397) were included. Variables most useful in differentiating between IEBt and IEDCS were dive type (free diving versus scuba diving), dive gas (compressed air versus mixed gas), dive profile (mean depth 13 versus 43 metres of seawater), symptom onset (when descending versus when ascending or surfacing), distribution of cochleovestibular symptoms (vestibular versus cochlear) and absence or presence of other DCS symptoms. Symptoms of difficult middle ear equalisation or findings consistent with middle ear barotrauma could not be reliably assessed in this context, being insufficiently reported in the IEDCS literature. CONCLUSIONS: There are multiple useful variables to help distinguish IEBt from IEDCS. Symptoms of difficult middle ear equalisation or findings consistent with middle ear barotrauma require further study as means of distinguishing IEBt and IEDCS.

Perforación duodenal por barotrauma durante colangiopancreatografía retrógrada endoscópica: caso clínico / Duodenal perforation due to barotrauma during endoscopic retrograde cholangiopancreatography: clinical case

Resumen Introducción: La perforación duodenal secundaria a la colangiopancreatografía retrógrada endoscópica (CPRE) es una complicación infrecuente y más aún cuando su mecanismo lesional es por barotrauma. La inyección de aire a alta presión produce un neumoretroperitoneo, cuya extensión y evolución lesional es incierta. Caso Clínico: Se comunica el caso de un hombre joven que sufrió una perforación duodenal durante una CPRE, su manejo quirúrgico y evolución. Discusión: El diagnóstico clínico-imagenológico suele ser precoz y claro si se detecta la lesión durante el procedimiento. El manejo terapéutico conservador o quirúrgico de esta entidad depende de varios factores que se analizan en el presente estudio.

Introduction: Duodenal perforation during endoscopic retrograde cholangiopancreatography (ERCP) is a rare complication and even more if the mechanism of injury is secondary to barotrauma. The injection of high-pressure-air produces a pneumo-retroperitoneum, the extent and lesional evolution of which is uncertain. Clinical Case: We report the case of a young man who suffered a duodenal perforation during an ERCP, his surgical management and evolution. Discussion: The clinical-imaging diagnosis is usually early and clear if the lesion is detected during the procedure. Its conservative or surgical management will depends on several factors that are analyzed in the present study.

High Incidence of Barotrauma in Patients With Severe Coronavirus Disease 2019.

OBJECTIVE.: To report the high incidence of barotrauma in critically ill patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19) and to discuss its implications. DESIGN.: Retrospective cohort study. SETTING.: ICU of an academic county hospital in Los Angeles, CA admitted from March 15-June 20, 2020. PATIENTS.: 77 patients with COVID-19 pneumonia. 75 patients met inclusion criteria. RESULTS.: 21% of patients with severe COVID-19 sustained barotrauma (33% of patients receiving IMV, 8% of patients receiving (NIV). There were no differences between the barotrauma and non-barotrauma groups regarding demographics, illness severity, or medications received, nor tidal volume or average/peak airway pressures in those receiving IMV. In the barotrauma group there was a greater proportion of patients receiving therapeutic anticoagulation (81% vs. 47%, p = 0.023) and ventilated using airway pressure release ventilation mode (13% vs. 0%, p = 0.043). Barotrauma was associated with increased likelihood of receiving a tracheostomy (OR 2.58 [0.23-4.9], p = 0.018]), longer median ICU length of stay (17 days vs. 7 days, p = 0.03), and longer median length of hospitalization (26 days vs. 14 days, p < 0.001). There was also a trend toward prolonged median duration of IMV (12.5 days vs 7 days, p = 0.13) and higher average mortality (56% vs 37%, p = 0.25). CONCLUSIONS.: Barotrauma is seen in 5-12% of patients with ARDS receiving IMV and is exceedingly rare in patients receiving NIV. We report a high incidence of barotrauma observed in critically ill patients with COVID-19 requiring either NIV or IMV. While there was a trend toward increased mortality in patients with barotrauma, this did not reach statistical significance. The increased incidence of barotrauma with COVID-19 may be a product of the pathophysiology of this disease state and a heightened inflammatory response causing rampant acute lung injury. Evidence-based medicine and lung-protective ventilation should remain the mainstay of treatment.

Eustachian tube function test as a predictor of middle ear barotrauma.

BACKGROUND: Most of the cases of middle ear barotrauma in divers are due to the impassability of the Eustachian tube. The aim of our study is to compare the results of tympanometry and Valsalva part of Eustachian Tube Function test (ЕТF-test) with the ability of divers to compensate for the change in ambient pressure in a hyperbaric chamber. MATERIAL AND METHODS: The study included 35 professional divers undergoing annual medical examination. For all subjects is measured first intratympanal pressure at rest, then after the maneuver of Valsalva with impedancemeter. Then a barofunction test (BFT) was performed to assess the diving fitness and the passability of the Eustachian tubes. It consists of divers compressing and decompressing in a hyperbaric chamber to a pressure of 2.2 ATA for 1 minute. Based on results from previous studies we are using a 20 DaPa cutoff point on the ETF test to predict Eustachian tube passability and a successful barofunction test. RESULTS: In the current study 24 divers have ETF test results higher than 20 DaPa. 3 divers have ETF test values lower than 20 DaPa in both ears, but none of them displayed difficulties in the BFT. 8 divers have ETF values lower than 20 DaPa in one ear and higher than 20 DaPa in the other. 7 of the last group displayed difficulties with the BFT in the ear with poor ETF result. CONCLUSIONS: We consider that the ETF test can be used to assess diving fitness as a screening method before performing a BFT, as values above 20 DaPa guarantee Eustachian tube function sufficient for diving activities. Values of 20 DaPa and less are not a definite predictor of the BFT results. The results of the ETF test can also be used in the usual work of an otorhinolaryngologist to evaluate Eustachian function in cases of unilateral disease of middle ear.

Recurrent Middle Ear Barotrauma in Student Pilots.

INTRODUCTION: The present study evaluated the efficacy of the nine-step inflation-deflation tympanometric test for predicting recurrence of middle ear barotrauma.METHODS: Student pilots who were diagnosed with middle ear barotrauma from October 2010 to April 2011 were enrolled. The grade of barotrauma was assigned using Teed's classification. All subjects underwent tympanometry and nine-step inflation-deflation testing at first visit and after improvement. Recurrence was monitored for 2 wk after they resumed flight. The relationships among the recurrence of middle ear barotrauma, the grade and duration of disease, and tympanometric and nine-step test results were evaluated.RESULTS: There were 35 cases enrolled. According to Teed's classification, 16 cases were Grade 0 (45.7%) and 11 cases were Grade I (31.4%). Grade III was shown in seven cases (20.0%) and one subject was Grade IV (2.9%). The mean duration of illness was 5.9 d. In the initial 9-step tests, 29 subjects (85.3%) failed to pass the entire test. On follow-up tests, eight cases (22.9%) failed. Seven pilots (20.0%) showed recurrent middle ear barotrauma after resumed flight. All of the cases with recurrence failed the follow-up nine-step tests. The nine-step test showed high sensitivity and specificity values for predicting recurrence. A clear correlation was observed between recurrence and nine-step test results.DISCUSSION: The nine-step inflation-deflation test provides useful information about Eustachian tube function. The nine-step test can be useful to reduce the risk of recurrence of middle ear barotrauma in pilots.Sohn JH. Recurrent middle ear barotrauma in student pilots. Aerosp Med Hum Perform. 2019; 90(8):681-687.

Dynamic Rabbit Model of Ear Barotrauma.

BACKGROUND: Establishing animal models of ear barotrauma (EB) to provide evaluation criteria for Eustachian tube dysfunction.METHODS: Using expansive sponges, 70 rabbits' right pharyngeal openings of the auditory tubes were blocked to cause dysfunction in the right Eustachian tubes. The right tympanic cavities of 65 rabbits were the Model Group (Subgroups 1-13) and these rabbits' left tympanic cavities were the Nonblockage Group. Hypobaric chamber tests (HCTs) at various vertical speeds (100 m · s-1, 75 m · s-1, 50 m · s-1, and 15 m · s-1) and altitudes (13,123 ft and 6562 ft) were conducted. The remaining five rabbits' right tympanic cavities were the Control Group and no HCTs were conducted. After HCTs, observations were made on rabbits' behavioral changes, oto-endoscope and tympanometry results, and pathological changes of the tympanic mucosae.RESULTS: 1) Rabbits in Subgroups 1-12 demonstrated EB, while Subgroup 13 and the Control Group did not. 2) Histopathology showed EB caused by rapid ascent/descent at 100 m · s-1 was more severe than that of 75 m · s-1 and 50 m · s-1 (P < 0.01), and that there were no significant differences in EB caused by rapid ascent/descent at 75 m · s-1 and 50 m · s-1 (P > 0.05). There were no significant differences in pathological injuries at the altitudes of 6562 ft and 13,123 ft (P > 0.05). 3) Based on tympanic membrane structures, tympanometry, and histopathological results, rabbits' EB can be classified into mild, moderate, and severe.DISCUSSION: EB's dynamic models could be established through HCTs on rabbits with Eustachian tube dysfunction.Wang B, Xu X, Lin J, Jin Z. Dynamic rabbit model of ear barotrauma. Aerosp Med Hum Perform. 2019; 90(8):696-702.

Recurrent facial nerve baroparesis in a military diver: a case report.

Middle ear barotrauma is common in diving. However, facial nerve baroparesis is a relatively rare complication. A dehiscent facial nerve canal may be a predisposing factor to developing this complication. Although there is an increasing number of facial baroparesis cases in the literature, they are likely still under-reported. In order to avoid unnecessary recompression treatments or detrimental effects to a professional diver's career, it is important to consider this in the differential diagnosis while evaluating dive injuries. This case report describes recurrent facial baroparesis in a military diver, which manifested on contralateral sides of his face. His initial presentation was misdiagnosed as an arterial gas embolism, which led to recompression treatment and a cardiac procedure. Upon recurrence about one year later, a complete work-up was done, which included an ENT evaluation and a CT scan. Imaging demonstrated a predisposing anatomic variant bilaterally. His symptoms resolved quickly and spontaneously both times, and he has been able to return to diving.

Recurrent and Progressive Facial Baroparesis on Flying Relieved by Eustachian Tube Dilation.

OBJECTIVES: Facial baroparesis is a rare phenomenon of seventh cranial nerve palsy traditionally reported in divers, with only 11 cases reported in aviation so far. It is important to correctly diagnose facial baroparesis given the differential diagnosis of stroke and decompression disease and offer appropriate treatment for recurrent cases. METHODS: The authors present the case of a patient with recurrent and progressive facial baroparesis treated with Eustachian tube balloon dilation. Institutional medical records were reviewed, and analysis of the current literature was performed. RESULTS: A 37-year-old woman experienced recurrent and progressive left facial paralysis on descent from altitude on commercial airline flights, with resolution between flights. The patient flew frequently for work-related trips and for the past 7 years had noted facial paralysis that began with mild asymmetry of the face and progressed to an inability to close her left eye. She denied any otologic symptoms other than ear fullness and pressure causing left otalgia. The right side was not involved. After treatment with Eustachian tube dilation, the patient has been on numerous flights with complete resolution of symptoms. CONCLUSIONS: This study presents a rare case of facial baroparesis on commercial flight descent that resolved after left Eustachian tube dilation. Although unilateral facial palsy can be concerning for stroke, a history of ear fullness and pressure may suggest facial baroparesis instead. For recurrent and progressive cases, Eustachian tube dilation should be considered for treatment.

A Free Diver with Hemoptysis and Chest Pain.

[Full article available at http://rimed.org/rimedicaljournal-2019-02.asp].

Inner ear barotrauma in divers: an evidence-based tool for evaluation and treatment.

OBJECTIVE: To systematically search the literature for studies evaluating the typical presentation and testing that is performed for divers with inner ear symptoms and then to create a tool for clinicians when evaluating a diver with inner ear symptoms. METHODS: Nine databases, including PubMed/MEDLINE were systematically searched through 31 January 2018. The PRISMA statement was followed. RESULTS: Three-hundred and two manuscripts were screened, 69 were downloaded and 21 met criteria to be included in this review. The articles were evaluated for symptomatic trends and initial evaluation work-up primarily focusing on inner-ear barotrauma (IEBt) and inner ear decompression sickness (inner ear DCS). The trends for IEBt were compared to typical inner ear DCS presentation based on large study inner ear DCS results consistent with the plethora of research available. Finally, the HOOYAH Tool was developed to assist the receiving provider to better determine the most likely diagnosis and thus initiate appropriate treatment. The HOOYAH Tool is comprised of the following: 1) H: hard to clear; 2) O: onset of symptoms; 3) O: otoscopic exam; 4) Y: your dive profile; 5) A: additional symptoms and 6) H: hearing. For each of these components, the typical presentation is described allowing the provider better to discern the correct diagnosis. CONCLUSION: The diagnosis of IEBt remains difficult to define short of visualization through surgical exploration. Early treatment is defined by conservative management with a subsequent observational period to determine symptomatic resolution and need for surgery. However, a similar differential diagnosis is inner ear DCS which requires early recompression. The HOOYAH tool provides a method for assisting the provider in forming a more confident decision regarding the underlying pathology and facilitation of the appropriate treatment.