Hyperbaric oxygen therapy for late radiation tissue injury

BACKGROUND

This is the third update of the original Cochrane Review published in July 2005 and updated previously in 2012 and 2016. Cancer is a significant global health issue. Radiotherapy is a treatment modality for many malignancies, and about 50% of people having radiotherapy will be long-term survivors. Some will experience late radiation tissue injury (LRTI), developing months or years following radiotherapy. Hyperbaric oxygen therapy (HBOT) has been suggested as a treatment for LRTI based on the ability to improve the blood supply to these tissues. It is postulated that HBOT may result in both healing of tissues and the prevention of complications following surgery and radiotherapy.

OBJECTIVES

To evaluate the benefits and harms of hyperbaric oxygen therapy (HBOT) for treating or preventing late radiation tissue injury (LRTI) compared to regimens that excluded HBOT.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 24 January 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the effect of HBOT versus no HBOT on LRTI prevention or healing.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. survival from time of randomisation to death from any cause; 2. complete or substantial resolution of clinical problem; 3. site-specific outcomes; and 4.

ADVERSE EVENTS

Our secondary outcomes were 5. resolution of pain; 6. improvement in quality of life, function, or both; and 7. site-specific outcomes. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Eighteen studies contributed to this review (1071 participants) with publications ranging from 1985 to 2022. We added four new studies to this updated review and evidence for the treatment of radiation proctitis, radiation cystitis, and the prevention and treatment of osteoradionecrosis (ORN). HBOT may not prevent death at one year (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.47 to 1.83; I2 = 0%; 3 RCTs, 166 participants; low-certainty evidence). There is some evidence that HBOT may result in complete resolution or provide significant improvement of LRTI (RR 1.39, 95% CI 1.02 to 1.89; I2 = 64%; 5 RCTs, 468 participants; low-certainty evidence) and HBOT may result in a large reduction in wound dehiscence following head and neck soft tissue surgery (RR 0.24, 95% CI 0.06 to 0.94; I2 = 70%; 2 RCTs, 264 participants; low-certainty evidence). In addition, pain scores in ORN improve slightly after HBOT at 12 months (mean difference (MD) -10.72, 95% CI -18.97 to -2.47; I2 = 40%; 2 RCTs, 157 participants; moderate-certainty evidence). Regarding adverse events, HBOT results in a higher risk of a reduction in visual acuity (RR 4.03, 95% CI 1.65 to 9.84; 5 RCTs, 438 participants; high-certainty evidence). There was a risk of ear barotrauma in people receiving HBOT when no sham pressurisation was used for the control group (RR 9.08, 95% CI 2.21 to 37.26; I2 = 0%; 4 RCTs, 357 participants; high-certainty evidence), but no such increase when a sham pressurisation was employed (RR 1.07, 95% CI 0.52 to 2.21; I2 = 74%; 2 RCTs, 158 participants; high-certainty evidence).

AUTHORS' CONCLUSIONS

These small studies suggest that for people with LRTI affecting tissues of the head, neck, bladder and rectum, HBOT may be associated with improved outcomes (low- to moderate-certainty evidence). HBOT may also result in a reduced risk of wound dehiscence and a modest reduction in pain following head and neck irradiation. However, HBOT is unlikely to influence the risk of death in the short term. HBOT also carries a risk of adverse events, including an increased risk of a reduction in visual acuity (usually temporary) and of ear barotrauma on compression. Hence, the application of HBOT to selected participants may be justified. The small number of studies and participants, and the methodological and reporting inadequacies of some of the primary studies included in this review demand a cautious interpretation. More information is required on the subset of disease severity and tissue type affected that is most likely to benefit from this therapy, the time for which we can expect any benefits to persist and the most appropriate oxygen dose. Further research is required to establish the optimum participant selection and timing of any therapy. An economic evaluation should also be undertaken.

Dental tourism and the risk of barotrauma and barodontalgia

Background and aim Dental tourism, which reflects the provision of health care services abroad, also includes a travelling component. Air travel after dental intervention may cause barotrauma and barodontalgia. This paper aimed to provide guiding principles regarding the minimal time interval between dental procedures and air travel to prevent these adverse effects.Methods A literature search was performed to reveal information with regards to complications related to flights following dental treatments. There is little research in this area and most of it has been conducted on the military aircrew population, which has different characteristics of flight and personnel than civilian commercial flights.Results The recommended time of flying is one week after most dental intervention and six weeks after a sinus lift procedure. The minimal time required between a procedure and flight is 24 hours after restorative treatment, 24-48 hours after simple extraction, 72 hours after nonsurgical endodontic procedure, surgical extraction, and implant placement, and at least two weeks after sinus lift procedure.Conclusions The provided guidelines may serve as a starting point for the clinician's decision-making. The tailoring of an individual treatment plan to the patient should take into consideration the patient's condition, dental procedure, complications and flight characteristics. Further research based on commercial flights is needed to formulate more accurate guidelines for the civilian population.

Unique challenges in naval military dentistry

Divers are regularly exposed to a unique and changing environment that dentists must consider when treating such patients. This review focuses around two case studies encountered in naval dentistry: (i) diving barotrauma (pressure-induced injury related to an air space); and (ii) scuba diving mouthpiece-related oral conditions. Each condition is described by its effect on the oral cavity and in particular the teeth. Then we generally review the latest literature on the different effects of scuba diving on the diver's head, face and oral regions and emphasize methods of dental disease prevention, diagnostic tools and treatment guidelines.

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.

A case of a critically injured diver with multiorgan failure and severe pulmonary overinflation syndrome in a resource-limited setting

A diver practicing controlled emergency ascent training on the island of Guam suffered bilateral pneumothorax, pneumomediastinum, coronary arterial gas embolism, and developed multiple organ dysfunction syndrome. Due to limitations of available resources he was medically managed in the intensive care unit until he could be transferred to University of California San Diego for definitive management. We provide an account of our management of the patient, the pathophysiology of injury as well as a review of the safety of recreational diving skills training, current standards of practice and potential pitfalls when considering proper management of a critically injured diver.

A comparison of two hyperbaric oxygen regimens: 2.0 ATA for 120 minutes to 2.4 ATA for 90 minutes in treating radiation-induced cystitis Are these regimens equivalent?

INTRODUCTION

Hyperbaric oxygen dosing variations exist in radiation cystitis treatment. The objectives of this study were to compare response and safety rates among patients with radiation cystitis treated with different protocols: 2.0 ATA (atmospheres absolute) for 120 minutes at the University of Pennsylvania; and 2.4 ATA for 90 minutes at Hennepin Healthcare.

MATERIALS AND METHODS

Retrospective chart review of radiation cystitis patients treated with hyperbaric oxygen at the University of Pennsylvania (January 2010-December 2018) and Hennepin Healthcare Minnesota (January 2014-December 2018). Primary outcome was response to treatment. Complications were limited to hyperbaric-related conditions. Regression analysis was performed with ordinal logistic regression and binary logistic regression.

RESULT

126 patients were included in the analysis (2.0 ATA: 66, 2.4 ATA: 60). Overall response rate was 75.4% (good) and was not significantly different between protocols (good response: 2.0 ATA 72.7% vs. 2.4 ATA 78.3% p=0.74). The 2.0 ATA group required additional treatments [2.0 ATA: 45.45 ± 14.5 vs. 2.4 ATA: 40.03 ± 9.7, p<0.05]. 6.1% (2.0 ATA) and 13.3% (2.4 ATA) required tympanostomy tube placement or needle myringotomy for otic barotrauma (p=0.22). Transfusion was associated with poorer outcomes (p<0.05).

CONCLUSION

Both groups - 2.0 ATA and 2.4 ATA - had similar response and complication rates. Blood transfusion is a negative prognostic factor for treatment outcome.

A Free Diver with Hemoptysis and Chest Pain

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

[Diving and asthma: Literature review]

INTRODUCTION

Scuba diving has long been contraindicated for asthmatics. Recommendations are evolving towards authorisation under certain conditions. Our objective was to review the literature on the risks associated with scuba diving among asthmatics and about recommendations on this subject.

MATERIALS AND METHODS

We used the MEDLINE and LiSSa databases, until June 2018, in French, English or Spanish language, with the keywords "asthma AND diving" and "asthme plongée" respectively. References to the first degree were analyzed.

RESULTS

We have included 65 articles. Risk of bronchospasm is well documented, particularly in cold and/or deep water, or in the event of exposure to allergens (compressor without filter). Nonasthmatic atopic divers may be at greater risk of developing bronchial hyper-reactivity. Although the theoretical risk exists, epidemiological studies do not seem to show an over-risk of barotrauma, decompression sickness or arterial gas embolism in asthmatics. French, British, American, Spanish and Australian societies agreed on the exclusion of patients with moderate to severe persistent asthma, FEV1<80%, active asthma in the last 48hours, exercise/cold asthma and poor physical fitness.

CONCLUSION

A diver's examination should include a triple assessment: asthma control, number of exacerbations and treatment compliance. Homogenizing the recommendations would improve the framework for the practice of diving among asthmatics and allow larger studies in this population. Communicating the current recommendations remains important to divers, dive instructors and doctors in the context of the development of scuba diving.

Alternobaric vertigo and facial baroparesis caused by scuba diving and relieved by chewing pineapple: a case report

Equalization of middle ear pressure is an important consideration for scuba divers. When middle ear pressure is asymmetric, a diver may experience alternobaric vertigo. Moreover, individuals with an underlying temporal bone dehiscence are predisposed to facial baroparesis. An understanding on behalf of fellow divers and emergency responders to recognize and differentiate facial baroparesis from decompression illness is critical. Misdiagnosis may lead to inappropriate treatment or unwarranted stoppage of diving. There have been a few dozen reported cases of facial baroparesis in the literature, but few have included firsthand accounts. This report describes an incidence of unilateral facial baroparesis preceded by alternobaric vertigo, with commentary from divers who witnessed the individual experiencing the facial paresis. The facial weakness in this case resolved within 15 minutes after the diver chewed on fresh pineapple. This report suggests that alternobaric vertigo may be a harbinger of facial baroparesis. Upon resurfacing divers should consider prophylactic measures that help to dilate the Eustachian tube such as chewing, yawning and swallowing in order to minimize the risk of middle ear pressure-induced vertigo or facial paresis.

Rescue therapeutic strategy combining ultra-protective mechanical ventilation with extracorporeal CO2 removal membrane in near-fatal asthma with severe pulmonary barotraumas: A case report

RATIONALE

Mechanical ventilation of severe acute asthma is still considered a challenging issue, mainly because of the gas trapping phenomenon with the potential for life-threatening barotraumatic pulmonary complications.

PATIENT CONCERNS

Herein, we describe 2 consecutive cases of near-fatal asthma for whom the recommended protective mechanical ventilation approach using low tidal volume of 6 mL/kg and small levels of PEEP was rapidly compromised by giant pneumomediastinum with extensive subcutaneousemphysema.

DIAGNOSES

Near fatal asthma.

INTERVENTION

A rescue therapeutic strategy combining extracorporeal CO2 removal membrane with ultra-protective extremely low tidal volume (3 mL/kg) ventilation was applied.

OUTCOMES

Both patients survived hospital discharge.

LESSONS

These 2 cases indicate that ECCO2R associated with ultra-protective ventilation could be an alternative to surgery in case of life-threatening barotrauma occurring under mechanical ventilation.

[The influence of military underwater activity on the oral cavity]

The military dentists who serve in the navy, treat divers, among other patients. Divers are being exposed to a changing, unique environment on a regular basis. The aim of this article is to review latest literature on the different effects of scuba diving on the diver's head, face and oral regions and to emphasize methods of disease prevention, diagnostic tools and treatment guidelines. The review focuses on diving barotrauma (pressure- induced injury related to an air space) as well as scuba diving mouthpiece-related oral conditions, which include facial, jaw pain and headaches, decompression sickness and mouthpiece-related herpes infection. Each condition is described by its effect on the oral cavity and in particular the teeth.

[Military aviation dentistry]

The aim of this article is to introduce the concepts of military aviation dentistry, including facial barotraumas (external otitic barotrauma, barosinusitis and barotitis- media), dental barotrauma, barodontalgia, and dental care for aircrews. Special considerations have to be made when planning restorative, endodontic, prosthodontic and surgical treatment to an aircrew patient. The article supplies the military dental officer with diagnostic and treatment guidelines, and the principles of prevention, periodic examination, and dental-related flight restriction.

Otologic Hazards Related to Scuba Diving

Context:

As of 2015, more than 23 million scuba diver certifications have been issued across the globe. Given the popularity of scuba diving, it is incumbent on every physician to know and understand the specific medical hazards and conditions associated with scuba diving.

Evidence Acquisition:

Sources were obtained from PubMed, MEDLINE, and EBSCO databases from 1956 onward and ranged from diverse fields including otologic reviews and wilderness medicine book chapters.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

Otologic hazards can be categorized into barotrauma-related injuries or decompression sickness.

Conclusion:

When combined with a high index of suspicion, the physician can recognize these disorders and promptly initiate proper treatment of the potentially hazardous and irreversible conditions related to scuba diving.

Current concepts of oral and maxillofacial rehabilitation and treatment in aviation

Aerospace medicine is the medical discipline responsible for assessing and conserving the health, safety, and performance of individuals involved in air and space travel. With the upward trend in airline travel, flight-related oral conditions requiring treatment have become a source of concern for aircrew members. Awareness and treatment of any potential physiological problems for these aircrews have always been critical components of aviation safety. In a flight situation, oral and maxillofacial problems may in fact become life-threatening clinical conditions. The unusual nature of aerospace medicine requires practitioners to have unique expertise. Special attention to aerospace medicine will open the way for professionals to develop and apply their skills and capabilities. Both dentists and aviators should be aware of the issues involved in aviation dentistry. This article presents the principles of prevention, treatment guidelines, and dental-related flight restrictions.

[Frontal sinus barotrauma: about a case and review of the literature]

Sinus barotrauma is the second most frequently reported injury after middle ear barotrauma. The front sinus is the most common site affected. This is a rare and specific pathology. We here report the case of a 26-year-old patient having severe left frontal pain with ipsilateral epistaxis after a dive. CT scan showed left frontal hemosinus. Patient evolution was good after therapy. Frontal sinus barotraumas are accidents related to the variations in environmental pressure. Epistaxis is a sign of serious health condition, CT scanner plays a role in evaluating potential predisposing factors and establishing monitoring procedures. Patient treatment aims to relieve symptoms and to remove predisposing factors. Frontal sinus barotraumas are a rare injury ; orbital and encephalic complications are exceptional. Their treatment coincides with that of their causal pathology.

Ear, nose and throat and non-acoustic barotrauma

The organs of the ear, nose and throat (ENT) contain air- or gas-filled cavities, which make them sensitive to pressure changes. There is a specific pathophysiology involved when these structures are exposed to non-acoustic press ure changes, which are usually not traumatic in normals. The concepts of pathophysiology, diagnosis and treatment of these traumas in an emergency setting are reviewed.

The O'Neill grading system for evaluation of the tympanic membrane: A practical approach for clinical hyperbaric patients

Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEB) are the two most common complications of clinical hyperbaric oxygen (HBO2) treatment. The current grading system, the Teed's Classification, was first described in 1944 with modifications to this system over the years, but none are specific for the evaluation and treatment of patients undergoing clinical HBO2 therapy. Currently, the standard of care is a baseline otoscopic examination performed prior to starting HBO2 therapy. Repeat otoscopy is required for patients having ETD, pain or other symptoms during the compression and/or decompression phase of the treatment. Results from these examinations are used to determine the proper course of treatment for the ETD or MEB. The Teed's classification was not intended to correlate with the consistency of diagnosis, the clinical approach to relieving symptoms or the treatment of the inflicted trauma. It is not a practical tool for the modern hyperbaric team. We describe a newer grading system, the O'Neill Grading System (OGS), which allows simple, practical and consistent classification of ETD and MEB by all members of the clinical hyperbaric medicine team. Based on the O'Neill Grade assigned, evidence supported suggestions for appropriate actions and medical interventions are offered.

The assessment and management of inner ear barotrauma in divers and recommendations for returning to diving

Inner ear barotrauma (IEBt) constitutes a spectrum of pressure-related pathology in the inner ear, with antecedent middle ear barotrauma (MEBt) common. IEBt includes perilymph fistula, intralabyrinthine membrane tear, inner ear haemorrhage and other rarer pathologies. Following a literature search, the pathophysiology, diagnosis, and treatment of IEBt in divers and best-practice recommendations for returning to diving were reviewed. Sixty-nine papers/texts were identified and 54 accessed. Twenty-five case series (majority surgical) provided guidance on diagnostic pathways; nine solely reported divers. IEBt in divers may be difficult to distinguish from inner ear decompression sickness (IEDCS), and requires dive-risk stratification and careful interrogation regarding diving-related ear events, clinical assessment, pure tone audiometry, a fistula test and electronystagmography (ENG). Once diagnosed, conservative management is the recommended first line therapy for IEBt. Recompression does not appear to cause harm if the diagnosis (IEBt vs IEDCS) is doubtful (limited case data). Exploratory surgery is indicated for severe or persisting vestibular symptoms or hearing loss, deterioration of symptoms, or lack of improvement over 10 days indicating significant pathology. Steroids are used, but without high-level evidence. It may be possible for divers to return to subaquatic activity after stakeholder risk acceptance and informed consent, provided: (1) sensorineural hearing loss is stable and not severe; (2) there is no vestibular involvement (via ENG); (3) high-resolution computed tomography has excluded anatomical predilection to IEBt and (4) education on equalising techniques is provided. There is a need for a prospective data registry and controlled trials to better evaluate diagnostic and treatment algorithms.

A prospective analysis of independent patient risk factors for middle ear barotrauma in a multiplace hyperbaric chamber

INTRODUCTION

Middle ear barotrauma (MEBT) is the most common complication of hyperbaric oxygen therapy (HBOT). We wished to determine whether independent risk factors could predict which patients will require tympanostomy tubes in order to continue HBOT.

METHODS

Data regarding demographics, medical history and physical examination were collected prospectively over one year. Multivariate logistic regression was used to analyse the data.

RESULTS

One hundred and six patients were included. The cumulative risk of MEBT over the first five treatments was 35.8% and that for needing tympanostomy tubes was 10.3%, while that for needing tubes at any time was 13.2%. Risk factors for MEBT on bivariate analysis were older age, history of ENT radiation and anticoagulant use. Risk factors for requiring tympanostomy tubes included a history of cardiovascular disease and patients being treated for an infective condition. The adjusted multivariate logistic model identified history of difficulty equalising as the only characteristic significantly associated with MEBT during the first five treatments, adjusted odds ratio (AOR) (95%CI): 11.0 (1.1 - 111.7). Being female, AOR (95%CI): 24.7 (1.8 - 339.7), and having a history of cardiovascular disease, AOR (95%CI): 20.7 (2.0 - 215.3), were significantly associated with the need for tympanostomy tubes during the first five HBOT, but there was no significant association between any other characteristics and the need for tubes at any point.

CONCLUSION

Despite some significant risk factors for MEBT being identified, we were unable to predict accurately enough which patients needed tympanostomy tubes during their HBOT to recommend these being placed prophylactically in selected patients.

[A study of the Eustachian tube function in patients with a scuba diving accident]

The scuba diving population has increased very much recently, bringing with it a rise in barotrauma. Ninety-seven patients with scuba diving-related accidents (34 males and 63 females; mean +/- SD: 36.6 +/- 10.3 years) and 39 healthy volunteers (9 males and 30 females; mean +/- SD: 41.1 +/- 16.9 years) without a history of Eustachian tube dysfunction participated in this study. All patients underwent audiometric measurements, including hearing testing, tympanometry, and Eustachian tube function testing (sonotubometry and impedance test). The tympanometry results of the majority of the patients were normal (Jerger A type), however, 83 of 97 patients (85.6%) were diagnosed as having Eustachian tube dysfunction: all patients had tubal stenosis. Compared with healthy volunteers, the Eustachian tube function in scuba diving patients was significantly lower. According to whether the affected parts were one ear or both ears, we classified these patients into 2 types, that is, the unilateral group and the bilateral group. The symptoms in the unilateral group were more serious than those in the bilateral group. In the unilateral group, the Eustachian tube functions of the affected ear did not always show lower than those of the healthy ear, so we thought that excessive positive pressure at the mesotympanum caused by the Valsalva maneuver might have affected not only the affected ear but also the healthy ear and have resulted in healthy ears being severely impaired by excessive positive pressure. To prevent scuba divers from pressure injury, we think that divers should have their Eustachian tube dysfunction accurately evaluated and any problems should be treated well.

[Decompression illness: minor symptoms, major consequences]

Nowadays, diving is being performed ever more frequently; it is thus important to take diving injuries into consideration in patients presenting with even minor complaints after diving. Every dive is risky and could result in decompression illness, barotrauma and/or death. We report on two cases of decompression illness: a 30-year old man, an occupational diver, and a 46-year old man, an experienced diver, who were both clinically suspected of having decompression illness and were treated with hyperbaric oxygen in a recompression chamber. Both were eventually symptom-free after several treatments. Decompression illness is caused by a reduction in ambient pressure, which results in intra- or extravascular bubbles. Symptoms vary and are dependent on the site affected: from minor pain to neurological symptoms and death. If patients are suspected of having diving injuries, we recommend contacting a centre specialised in diving and hyperbaric medicine. Recompression in a hyperbaric chamber is the definitive treatment for decompression illness and should be performed as soon as possible.

Middle ear barotrauma after hyperbaric oxygen therapy - the role of insuflation maneuvers

OBJECTIVE

To analyze the association of insuflation maneuvers status before hyperbaric oxygen therapy with middle ear barotrauma.

MATERIALS AND METHODS

Fouty-one patients (82 ears) admitted to the Department of Hyperbaric Medicine from May 2011 to July 2012. Assessments occurred: before and after the first session, after sessions with symptoms. During the evaluations were performed: otoscopy with Valsalva and Toynbee maneuvers, video otoscopy and specific questionnaire. Middle ear barotrauma was graduated by the modified Edmond's scale. Tubal insuflation was classified in Good, Median and Bad according to combined results of Valsalva and Toynbee maneuvers.

INCLUSION CRITERIA

patients evaluated by an otolaryngologist before and after the first session, with no history of ear disease, who agreed to participate in the research (convenience sample).

RESULTS

Of the 82 ears included in the study, 32 (39%) had barotrauma after the first session. The rate of middle ear barotrauma according to tubal insuflation was: 17.9% (Good insuflation) 44.4% (Median insuflation) and 55.6% (Bad insuflation) (P = 0.013).

CONCLUSION

Positive Valsalva and Toynbee maneuvers before the first session, alone or associated were protective factors for middle ear barotrauma by ear after the first session.

ENT morbidity at high altitude

BACKGROUND

People suffer unique health problems in high altitude areas, due to such factors as elevation, aircraft ascent and descent, extreme cold, hypoxia, hypobaria, and low relative humidity. This study was conducted to evaluate ENT morbidity at high altitude.

METHODS

Serving soldiers introduced to a high altitude environment who presented with various ENT symptoms were examined to identify ENT disease. In addition, patients undergoing hyperbaric chamber therapy, tracheostomy and treatment of cold injuries were also examined for ENT problems.

RESULTS

The following were detected: 13 cases of otic barotrauma, 11 cases of sinus barotrauma, three cases of vertigo, six cases of pinna frostbite, three cases of barotrauma caused by hyperbaric chamber therapy, an unusually high incidence of epistaxis, and innumerable patients with high altitude pharyngitis.

CONCLUSION

Diseases of the ear, nose and throat contribute significantly to high altitude morbidity. In a military context, health education of troops is necessary to avoid such problems.

[Diagnosis, treatment and medical evaluation of sinusitis and nasal polyp in aircrew]

OBJECTIVE

To sum up the experiences of diagnosis, treatment and medical evaluation of sinusitis and nasal polyp in aircrew.

METHOD

Ninety three aircrew with sinusitis and nasal polyp were included in the study.

RESULT

There were 11 cases with acute sinusitis and 82 cases with chronic sinusitis and nasal polyp. Of the 82 cases, there were 46 cases in class I (including 39 cases with symptoms and signs on ground in Ia, 7 cases only with signs in Ib), 36 cases in class II (no symptoms on ground but with symptoms of secondary barotraumas in flight, including 14 cases with secondary barosinusitis in IIa, 13 cases with secondary barotrauma in IIb, 9 cases with secondary barosinusitis and barotrauma in IIc ). Of the 82 cases, there were 24 cases in 1 stage of type I, 38 cases in 2 stage of type I, 7 cases in 3 stage of type I, 2 cases in 1 stage of type II, 6 cases in 2 stage of type II, 3 cases in 3 stage of type II, 2 cases in type III. Eighty four cases continued their flying jobs and 9 cases were permanently grounded.

CONCLUSION

Flying safe can be endangered by sinusitis and nasal polyp alone or with its secondary barotraumas. Chronic sinusitis and nasal polyp complicated with barotraumas are important causation for medical grounding. The aircrew with sinusitis and nasal polyp will be allowed to continue their flying jobs only after getting well curative effect and normal gas pressures of ear and nasal sinus.

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 hearing loss, 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.

Barotrauma and Decompression Illness of the Inner Ear

INTRODUCTION

Diving accidents affecting the inner ear are much more common than was once thought. Among the 319 patients treated in our clinic between January 2002 and November 2005, 46 cases involved 44 divers with symptoms of acute inner ear disorders. The objective of the present article is to investigate the symptoms of the acute disorders and assess any residual damage.

STUDY DESIGN

Retrospective case analysis.

MATERIALS AND METHODS

The medical records were used to study the cases of 18 divers treated for inner ear decompression illness on 20 occasions and 26 divers who had inner ear barotrauma. The symptoms of the disorder at the beginning of treatment, latency period before the first therapeutic measures, kind of initial therapy, symptoms after the accident, and hearing and balance functions at the last examination in our clinic were assessed. Divers with inner ear decompression illness were examined via means of transcranial or carotid Doppler ultrasonography for the presence of a vascular right-to-left (R/L) shunt.

RESULTS

Of 18 divers with inner ear decompression illness, 17 reported vertigo as the main symptom. In one diver, the inner ear decompression illness was manifested bilaterally. The divers with inner ear decompression illness had been treated with hyperbaric oxygen therapy in 14 of 20 cases; the average latency period before the start of therapy was 40 hours (median, 10 h). In 15 (83%) of 18 patients, a large R/L shunt was detected, and in 14 (78%) of 18 patients, residual cochleovestibular damage was detected. Only 9 of 26 patients with inner ear barotrauma mentioned feeling dizzy, and in no patient was vertigo the main symptom. Twenty-one patients complained of tinnitus, whereas 20 complained of hearing loss. The hearing loss ranged from an unobtrusive difference of 10 dB between the ears up to complete deafness. Three patients were subjected to tympanoscopy because of suspected rupture of the round window membrane. Of patients with inner ear barotrauma, 78% had residual cochleovestibular damage.

CONCLUSION

We describe for the first time a patient with bilateral manifestation of inner ear decompression illness. Inner ear decompression illness is frequently associated with a R/L shunt; therefore, after a diving accident, the patient's fitness to dive should be assessed via a specialist in diving medicine. Both decompression illness and barotrauma of the inner ear result in residual cochleovestibular damage in more than three of four patients.

Bilateral tension pneumothoraces following jet ventilation via an airway exchange catheter

We report a case involving a 55-year-old man who had a recent resection of tracheal carcinoma and tracheal reanastomosis. He subsequently developed tracheomalacia and anastomotic dehiscence requiring airway stenting via an armored endotracheal tube (ETT). Placement of the armored ETT was technically difficult. It required insertion of an airway exchange catheter through the tracheal stoma to oxygenate, ventilate, and serve as a guide for ETT placement through the tracheotomy and across the dehiscence. During transtracheal jet ventilation our patient developed bilateral tension pneumothoraces requiring cardiopulmonary resuscitation and chest tube placement. The patient was quickly recovered, stabilized, and later discharged after a prolonged intensive care unit (ICU) course. We review the recommendations for jet ventilation via airway exchange catheters, common problems during this technique, and potential methods for avoiding these problems. The risk of barotrauma and pneumothoraces during jet ventilation via an airway exchange catheter should be kept in mind.

Scuba diving: What you and your patients need to know

Self-contained underwater breathing apparatus (SCUBA) diving continues to gain popularity. General practitioners need to know the health requirements and contraindications so they can counsel patients appropriately. SCUBA diving injuries may not be apparent immediately and require knowledge and understanding for accurate diagnosis and treatment.

High-pressure water jet injury to the pharynx, requiring intubation

We report a case of upper airway obstruction following high-pressure water jet injury to the pharynx incurred from a car wash jet. Injuries from high-pressure water jets are relatively rare and, to the best of our knowledge, airway obstruction as a result has not been reported. Since this unusual injury may be associated with life-threatening complications, it must be promptly recognized and treated.

The contribution of biophysical lung injury to the development of biotrauma

Patients with severe acute respiratory distress syndrome who die usually succumb to multiorgan failure as opposed to hypoxia. Despite appropriate resuscitation, some patients' symptoms persist on a downward spiral, apparently propagated by an uncontained systemic inflammatory response. This phenomenon is not well understood. However, a novel hypothesis to explain this observation proposes that it is related to the life-saving ventilatory support used to treat the respiratory failure. According to this hypothesis, mechanical ventilation per se, by altering both the magnitude and the pattern of lung stretch, can cause changes in gene expression and/or cellular metabolism that ultimately can lead to the development of an overwhelming inflammatory response-even in the absence of overt structural damage. This mechanism of injury has been termed biotrauma. In this review we explore the biotrauma hypothesis, the causal relationship between biophysical injury and organ failure, and its implications for the future therapy and management of critically ill patients.

[Effect of using several levels of positive end-expiratory pressure over barotrauma's induced lung injury in a model of isolated and perfused rabbit lungs]

The use of Positive end-expiratory pressure (PEEP) as a strategy of mechanical ventilation offers its advantages, such as improved oxygenation, without causing alveolar overstretching and barotrauma. We aim to investigate the effect of several levels of PEEP on barotrauma and, whether an optimal level of PEEP exists. Forty-eight New Zealand rabbits (2.5-3.5 kg) were divided into four groups with PEEP settings of 0, 4, 8 and 12 cmH2O, at increasing levels of inspiratory volume (IV). This was done in blood perfused rabbit lungs and in lungs perfused with a Buffer-Albumin Solution. We observed that lungs ventilated with PEEP 0 cmH2O suffered pulmonary rupture at high IV (300cc), with significant increases of Pap (Pulmonary artery pressure) and FFR (Fluid filtration rate). Lungs ventilated with PEEP 8 and 12 suffered pulmonary rupture at lower IV (200cc and 150cc vs. 300cc respectively) On the other hand, lungs ventilated with PEEP 4 cmH2O reached the highest IV (400cc), in addition, they showed the lowest elevations of Pap and FFR. The acellular lungs ventilated with PEEP 4, 8 and 12 showed pulmonary rupture at lower IV when compared with cellular ones (300cc vs. 400cc: 100cc vs. 200cc and 100cc vs. 150cc respectively). We concluded that an optimal PEEP exists, which protects against barotrauma, however, excess of PEEP could enhance its development. The blood could contain some mediators which attenuate the damage induced by barotrauma.

[One-sided acquired pulmonary lobar emphysema -- successful treatment with selective intubation and one-sided high-frequency ventilation]

Mechanical ventilation of preterm and newborn infants is associated with the risk of inducing a pulmonary baro- or volutrauma which may lead to one-sided acquired pulmonary lobar emphysema (APLE). We report a case of a preterm infant with severe APLE compromising hemodynamics due to mediastinal-shift, which was successfully treated with selective one-sided intubation and high-frequency ventilation. We assume that a brief malposition of the endotracheal tube initiated the emphysema of the left pulmonary lobe. We deduce recommendations for avoiding APLE from literature and our experience.

[Diving accidents. Emergency treatment of serious diving accidents]

Decompression injuries are potentially life-threatening incidents mainly due to a rapid decline in ambient pressure. Decompression illness (DCI) results from the presence of gas bubbles in the blood and tissue. DCI may be classified as decompression sickness (DCS) generated from the liberation of gas bubbles following an oversaturation of tissues with inert gas and arterial gas embolism (AGE) mainly due to pulmonary barotrauma. People working under hyperbaric pressure, e.g. in a caisson for general construction under water, and scuba divers are exposed to certain risks. Diving accidents can be fatal and are often characterized by organ dysfunction, especially neurological deficits. They have become comparatively rare among professional divers and workers. However, since recreational scuba diving is gaining more and more popularity there is an increasing likelihood of severe diving accidents. Thus, emergency staff working close to areas with a high scuba diving activity, e.g. lakes or rivers, may be called more frequently to a scuba diving accident. The correct and professional emergency treatment on site, especially the immediate and continuous administration of normobaric oxygen, is decisive for the outcome of the accident victim. The definitive treatment includes rapid recompression with hyperbaric oxygen. The value of adjunctive medication, however, remains controversial.

An unusual type of severe barotrauma owing to automobile tire biting in a child

The authors report a rare case of a barotraumatic pneumothorax and pneumomediastinum associated with esophageal perforation and orbital emphysema. A 4-year-old boy presented with sudden respiratory distress after blowout of a defective tire that he bit. Computed tomography scan showed right pneumothorax and bilateral orbital emphysema. A linear rupture has been detected in the cervical esophagus in esophagoscopy. Stamm gastrostomy and tube thoracostomy were performed, and broad-spectrum antibiotics have been introduced. Oral feeding started 23 days after blowout of tire, and the patient was discharged 50 days after injury.

Behandlung akuter kochleovestibul�rer Sch�digungen nach dem Tauchen

BACKGROUND

There has been a steady in-crease of recreational scuba divers in the last years. The majority of diving associated diseases involve otorhinolaryngology, the most important of which are cochleovestibular dysfunctions as these can lead to permanent inner ear failure.

MATERIAL AND METHODS

We discuss the origin and clinical symptoms, as well as the therapy, of both inner ear barotrauma and inner ear decompression illness. Our own experiences are considered together with a review of the literature from the last decade.

RESULTS

Inner ear decompression illness seems to be a relatively common diving associated incident and is not as rare as previously thought.

DISCUSSION

Hyperbaric oxygen therapy is the treatment of choice for patients with inner ear decompression sickness, but is contraindicated in patients with inner ear barotrauma. As long as an inner ear decompression illness can not be ruled out, we suggest that every patient should be treated using hyperbaric oxygen therapy but only after bilateral paracentesis.

Incidence, risk factors and outcome of barotrauma in mechanically ventilated patients

OBJECTIVE

To determine the incidence, risk factors, and outcome of barotrauma in a cohort of mechanically ventilated patients where limited tidal volumes and airway pressures were used.

DESIGN AND SETTING

Prospective cohort of 361 intensive care units from 20 countries.

PATIENTS AND PARTICIPANTS

A total of 5183 patients mechanically ventilated for more than 12 h.

MEASUREMENTS AND RESULTS

Baseline demographic data, primary indication for mechanical ventilation, daily ventilator settings, multiple-organ failure over the course of mechanical ventilation and outcome were collected. Barotrauma was present in 154 patients (2.9%). The incidence varied according to the reason for mechanical ventilation: 2.9% of patients with chronic obstructive pulmonary disease; 6.3% of patients with asthma; 10.0% of patients with chronic interstitial lung disease (ILD); 6.5% of patients with acute respiratory distress syndrome (ARDS); and 4.2% of patients with pneumonia. Patients with and without barotrauma did not differ in any ventilator parameter. Logistic regression analysis identified as factors independently associated with barotrauma: asthma [RR 2.58 (1.05-6.50)], ILD [RR 4.23 (95%CI 1.78-10.03)]; ARDS as primary reason for mechanical ventilation [RR 2.70 (95%CI 1.55-4.70)]; and ARDS as a complication during the course of mechanical ventilation [RR 2.53 (95%CI 1.40-4.57)]. Case-control analysis showed increased mortality in patients with barotrauma (51.4 vs 39.2%; p=0.04) and prolonged ICU stay.

CONCLUSIONS

In a cohort of patients in whom airway pressures and tidal volume are limited, barotrauma is more likely in patients ventilated due to underlying lung disease (acute or chronic). Barotrauma was also associated with a significant increase in the ICU length of stay and mortality.

Diving emergencies

Self-Contained Underwater Breathing Apparatus (SCUBA) diving popularity is increasing tremendously, reaching a total of 9 million people in the US during 2001, and 50,000 in the UK in 1985. Over the past 10 years, new advances, equipment improvements, and improved diver education have made SCUBA diving safer and more enjoyable. Most diving injuries are related to the behaviour of the gases and pressure changes during descent and ascent. The four main pathologies in diving medicine include: barotrauma (sinus, otic, and pulmonary); decompression illness (DCI); pulmonary edema and pharmacological; and toxic effects of increased partial pressures of gases. The clinical manifestations of a diving injury may be seen during a dive or up to 24 h after it. Physicians living far away from diving places are not excluded from the possibility of encountering diver-injured patients and therefore need to be aware of these injuries. This article reviews some of the principles of diving and pathophysiology of diving injuries as well as the acute treatment, and further management of these patients.

Critically ill patients with severe acute respiratory syndrome

CONTEXT

Severe acute respiratory syndrome (SARS) is a newly recognized infectious disease capable of causing severe respiratory failure.

OBJECTIVE

To determine the epidemiological features, course, and outcomes of patients with SARS-related critical illness.

DESIGN, SETTING, AND PATIENTS

Retrospective case series of 38 adult patients with SARS-related critical illness admitted to 13 intensive care units (ICUs) in the Toronto area between the onset of the outbreak and April 15, 2003. Data were collected daily during the first 7 days in the ICUs, and patients were followed up for 28 days.

MAIN OUTCOME MEASURES

The primary outcome was mortality at 28 days after ICU admission. Secondary outcomes included rate of SARS-related critical illness, number of tertiary care ICUs and staff placed under quarantine, and number of health care workers (HCWs) contracting SARS secondary to ICU-acquired transmission.

RESULTS

Of 196 patients with SARS, 38 (19%) became critically ill, 7 (18%) of whom were HCWs. The median (interquartile range [IQR]) age of the 38 patients was 57.4 (39.0-69.6) years. The median (IQR) duration between initial symptoms and admission to the ICU was 8 (5-10) days. Twenty-nine (76%) required mechanical ventilation and 10 of these (34%) experienced barotrauma. Mortality at 28 days was 13 (34%) of 38 patients and for those requiring mechanical ventilation, mortality was 13 (45%) of 29. Six patients (16%) remained mechanically ventilated at 28 days. Two of these patients had died by 8 weeks' follow-up. Patients who died were more often older, had preexisting diabetes mellitus, and on admission to hospital were more likely to have bilateral radiographic infiltrates. Transmission of SARS in 6 study ICUs led to closure of 73 medical-surgical ICU beds. In 2 university ICUs, 164 HCWs were quarantined and 16 (10%) developed SARS.

CONCLUSIONS

Critical illness was common among patients with SARS. Affected patients had primarily single-organ respiratory failure, and half of mechanically ventilated patients died. The SARS outbreak greatly strained regional critical care resources.