Analysis of factors related to failure in the pressure test: a six-year experience in Taiwan.

INTRODUCTION: The Republic of China Navy instituted the pressure test as one of the selection tools for diving troops and submarine crews. We analyzed factors associated with failure in the pressure test. METHODS: This was a retrospective cohort study designed to investigate pressure test failure in Navy recruits between January 2010 and August 2015. The recruits received pressurization in a hyperbaric chamber to a simulated depth of 112 feet of seawater (fsw) at a rate of 25 fsw/minute. Data describing trainee demographics, disease history, causes and depth of failure, as well as type of injury, were extracted from case notes and facility databases for statistical analysis. RESULTS: Of 3,608 trial cohorts, there were 435 failures, with an overall failure rate of 12.06%. About 95% of these failure trials were within a simulated depth of 60 fsw. Fifty-seven (57) failures did not record causes of failure. Among the other 378 failures, the most commonly identified causes were ear barotrauma (365 trials, 96.56%) and sinus barotrauma (10 trials, 2.65%). Statistical analysis revealed that recent upper respiratory tract infection, allergic rhinitis, and cigarette smoking were all significantly associated with higher incidence of middle ear barotrauma. CONCLUSIONS: Our results suggest that pressure testing to a depth of 60 fsw is effective in disqualifying personnel entering diving and submarine service. Recent infection of the upper respiratory tract, allergic rhinitis and cigarette smoking are risk factors for middle ear barotrauma, resulting in failure of the pressure test.

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.

[Aerosinusitis. Part 2: Diagnosis, therapy and recommencement of flight duties]. / Aerosinusitis. Teil 2: Diagnostik, Therapie und Wiederaufnahme der Flugtätigkeit.

Aerosinusitis more frequently affects the frontal sinus than the maxillary sinus and mostly occurs during descent. Sinonasal diseases and anatomic variations leading to obstruction of paranasal sinus ventilation favor the development of aerosinusitis. This Continuing Medical Education (CME) article is based on selective literature searches of the PubMed database (search terms: "aerosinusitis", "barosinusitis", "barotrauma" AND "sinus", "barotrauma" AND "sinusitis", "sinusitis" AND "flying" OR "aviator"). Additionally, currently available monographs and further articles that could be identified based on the publication reviews were also included. In part 2, diagnostic measures, drug therapy, balloon dilatation and endoscopic sinus surgery are presented, along with a discussion regarding when flight attendants and pilots are able to resume their work. Endoscopic surgery to expand the natural drainage pathways of the affected sinuses with minimal surgical trauma to the healthy mucous membranes is largely successful.

Diagnosis and management of headache attributed to airplane travel.

The headache attributed to airplane travel, also named "airplane headache", is characterized by the sudden onset of a severe head pain exclusively in relation to airplane flights, mainly during the landing phase. Secondary causes, such as upper respiratory tract infections or acute sinusitis, must be ruled out. Although its cause is not thoroughly understood, sinus barotrauma should be reasonably involved in the pathophysiological mechanisms. Furthermore, in the current International Classification of Headache Disorders, rapid descent from high altitude is not considered as a possible cause of headache, although the onset of such pain in airplane travellers or aviators has been well known since the beginning of the aviation era. On the basis of a survey we conducted with the courteous cooperation of people who had experienced this type of headache, we proposed diagnostic criteria to be added to the forthcoming revision of the International Classification of Headache Disorders. Their formal validation would favour further studies aimed at improving knowledge of the pathophysiological mechanisms involved and at implementing preventative measures.

Class II barodontalgia: review and report of a case.

Barodontalgia is a rarely reported condition involving changes in ambient pressure resulting in tooth pain. According to Ferjentsik and Aker, Class II barodontalgia is observed in teeth that have pre-existing pulpal disease and an ultimate diagnosis of irreversible pulpitis.1 This article describes a case of Class II barodontalgia that was experienced on a commercial airline flight and reviews current knowledge regarding this phenomenon, including proposed etiologic mechanisms.

The role of radiology in dive-related disorders.

Recreational scuba diving has continued to grow in popularity in the past several decades, and military diving remains an integral part of ship husbandry, explosives and ordinance disposal, and special warfare. Although relatively uncommon, disorders such as decompression sickness and arterial gas embolism can be fatal, whereas disorders such as ear baro-trauma and dysbaric osteonecrosis are not fatal but can cause significant morbidity. An extensive literature search was performed to comprehensively examine the current role of diagnostic radiology with respect to diving medicine. In selected cases, diagnostic imaging can be of potential benefit for evaluation. Diagnostic imaging plays a useful role in the screening of certain individuals for future fitness to dive. Radiological imaging has also been of paramount importance in postmortem evaluation of dive casualties.

[Severe decompression sickness in divers]. / Der schwere Dekompressionsunfall.

The term "decompression illness (DCI)" is a disorder which arises from the presence of ectopic gas bubbles following decompression. Scuba diving poses the risk of two typically clinical syndromes: decompression sickness (DCS) and arterial gas embolism (AGE). DCS results from the formation of gas bubbles in the tissues of the body and in the blood due to rapid reduction of the environmental pressure. AGE is caused by pulmonary overinflation if the breathing gas cannot be exhaled adequately during the ascent. Although the pathophysiological mechanisms of these two disorders are quite different, both of them lead to the same result: inert gas bubbles that may cause impairment of vital functions due to hypoxia. Recognizing the signs and symptoms of DCI is the first step of the therapy. The emergency treatment contains: basic life support, advanced life support--if necessary, horizontal positioning of the victim, administration of 100% normobaric oxygen via face mask or endotracheal tube, rehydration, rapid transportation to the nearest emergency department/hyperbaric facility for definitive treatment in order to prevent serious neurological sequelae.

Point prevalence of barotitis in children and adults after flight, and effect of autoinflation.

The most common cause of barotitis is pressure changes during descent in aviation. Equilibration is normally achieved by swallowing, jaw movements, yawning, or chewing, but some have to perform a Valsalva maneuver several times during descent and even by these means some fail. The aim of the study was to estimate the point prevalence of barotrauma in children and adults after flight, and to test the effect of an autoinflation device (Otovent), in improving negative middle ear pressure after flight. Questionnaires and Otovent, were distributed to all air passengers in eight incoming flights. The questionnaires inquired about nasal allergy, nasal congestion, previous and actual ear pain, use of decongestants and experience of inflating the Otovent set during descent. After flight, the passengers were offered an ear examination including otoscopy and tympanometry both before and after a Valsalva maneuver, as well as after Otovent inflation. Otoscopic signs of barotitis were found in 10% of the adults and in 22% of the children. Negative middle ear pressure of more than 10 hPa after landing was found in 20% of the adults and in 40% of the children. The Valsalva maneuver normalized the pressure in 46% of the adults and in 33% of the children. Of the adults, 73%, and of the children, 69% with an unsuccessful Valsalva maneuver could improve or normalize the middle ear pressure by inflating the Otovent set. In conclusion, we recommend autoinflation using the Otovent set to air passengers with problems clearing the ears during flight.

Long-term follow-up of aviators after functional endoscopic sinus surgery for sinus barotrauma.

Prior to endonasal endoscopic advances for the treatment of sinus disease, surgical results for aviators with recurrent sinus barotrauma (RSB) were inconsistent. Between 1988 and 1992, 54 aviators, who were permanently or temporarily grounded, underwent functional endoscopic sinus (FES) surgery in an attempt to return them to active flying status. Follow-up in the immediate postoperative period revealed that 98% of these aviators returned to active flight duty. A questionnaire was mailed to each of these aviators to compare their preoperative and long-term postoperative symptoms and determine their current flying status. Long-term follow-up time ranged from 20 to 72 mo with average of 48 mo. Of the aviators who responded to the survey, 92% have continued their flying duties and do not report difficulties with RSB. We conclude that FES surgery is effective in the short- and long-term management RSB in aviators.