El buceo recreativo y la otorrinolaringología: ¿qué sabemos y deberíamos saber? / Recreational diving and otolaryngology: what do we know and should we know?

El buceo recreativo es una práctica cada vez más popular en la población mundial, sin embargo, no está exenta de riesgos. A medida que transcurre una inmersión, el buzo es susceptible a una serie de cambios de presión que afectan las distintas cavidades que contienen aire dentro del cuerpo humano, tales como el oído, cavidades paranasales y los pulmones. Existe un gran espectro de patologías asociadas al buceo, explicándose la mayoría de ellas por el barotrauma asociado, cuya gravedad depende de la magnitud del daño asociado, pudiendo presentar desde manifestaciones a nivel local, así como también a nivel sistémico. Las patologías otológicas suelen ser las más frecuentes y el principal motivo de consulta en este tipo de pacientes. Sin embargo, las afecciones otoneurológicas, rinosinusales, de vía aérea y sistémicas pueden ser comunes dependiendo de cada perfil de buceo. Actualmente no existen recomendaciones locales sobre esta práctica, por lo que el conocimiento de la fisiología, fisiopatología y el tratamiento de las patologías otorrinolaringológicas asociadas deben ser conocidas a medida que este deporte se vuelve cada vez más popular. Se realizó una revisión de la literatura sobre las distintas afecciones otorrinolaringológicas con el fin de sistematizarlas y elaborar recomendaciones para establecer una práctica segura.

Recreational diving is an increasingly popular practice in the world; however, it is not without risks. As a dive progresses, the diver is susceptible to a series of pressure changes that affect the air-containing cavities, such as the ear, paranasal cavities, and lungs. There is a large spectrum of pathologies associated with diving, most of them being explained by associated barotrauma, the severity of which depends on the magnitude of the associated damage, could present local manifestations, as well as at systemic level. Otological pathologies are usually the most frequent and the main reason for consultation in this type of patients, however, otoneurological, rhinosinusal, airway and systemic conditions can be common depending on each diving profile. Currently there are no local recommendations on this practice, therefore, knowledge of the physiology, pathophysiology and treatment of associated otorhinolaryngological pathologies should be known as this sport becomes increasingly popular. A review of the literature on the different ear, nose and throat conditions was carried out in order to systematize them and develop recommendations to establish a safe practice.

The panic triangle: onset of panic in scuba divers.

Panic arising from physical or psychological stress is a common issue in reported incidents and accidents in scuba diving. Due to its effect on perception, thinking and diver behavior, the panic reaction is often a significant factor in the generation or escalation of problems, potentially leading to injuries and fatalities. The instinctive behaviors associated with panic are incompatible with the constraints of scuba diving (e.g., flight response to threat, leading to rapid ascent). Although the dangers are well known, the psychological mechanisms of panic and the implications for prevention/risk reduction are not sufficiently highlighted to recreational divers. In applied psychology, there are grounded theoretical models which describe the onset and maintenance of anxiety and panic, and an evidence base for approaches to anxiety management. For example, these models are used within structured psychological approaches for people experiencing anxiety disorders; and panic attacks are resolvable. Based on these models and underlying theory, this article proposes a new, accessible model for panic in divers. The potential uses of the model are to: (1) provide a simple framework for divers to understand the onset of panic; (2) promote the need for adequate training; (3) describe the importance of staying within training standards, qualifications and personal limitations; (4) support diver and dive educator understanding of individual factors in panic reactions (e.g. psychiatric conditions) placing greater emphasis on psychological fitness to dive; and (5) draw attention to approaches to improved regulation of emotion and promote individual responsibility.

Decreased Incidence of Pulmonary Barotrauma After Discontinuation of Emergency Free Ascent Training.

INTRODUCTION: Because a significant association between training to perform emergency free ascent (EFA) and the occurrence of pulmonary barotrauma (PBT) was demonstrated in 2006, the Belgian Underwater Federation (BUF) decided to discontinue this procedure. An evaluation was needed 10 yr after the implementation of this change. METHODS: All medical records with a diagnosis of PBT that occurred in Belgium from November 2006 to September 2016 were prospectively collected. Data on the proportion of in-water skills training dives were obtained from BUF. RESULTS: A total of 5 cases of PBT were identified, significantly down from 34 cases in the previous 10-yr period. Of those cases, four occurred during training dives (two during ascent training). Analysis of the case files furthermore showed that two should have been medically disqualified from diving. Compared with the retrospective cohort (1995-2005), incidences are significantly reduced from 0.83 to 0.078/10,000 training dives and from 3.33 to 0.11/10,000 ascent-training dives; concomitantly, the incidence of PBT in nontraining dives also was reduced (from 0.0042 to 0.0014×10-4/10,000 dives), possibly because less divers undertake the EFA procedure in case of a technical incident and have learned to solve the problem differently. DISCUSSION: Discontinuation of emergency free ascent training was associated with a reduction in the incidence of PBT in the 10-yr follow-up period. We observed a significant decrease of PBT during training dives, confirming the hypothesis that EFA training in its previous form did not contribute significantly to diving safety.Lafère P, Germonpré P, Guerrero F, Marroni A, Balestra C. Decreased incidence of pulmonary barotrauma after discontinuation of emergency free ascent training. Aerosp Med Hum Perform. 2018; 89(9):816-821.

Back to the future: occupational diver training in Australia.

The Australian Diver Accreditation Scheme (ADAS) had its genesis in the 1990s in response to a need to produce occupational divers who were trained to international standards with the necessary skills to safely undertake complex work in high-risk environments. Well-trained dive teams who are 'fit-for-purpose' can be regarded as the highest level of risk control in preventing accidents and workplace morbidity. Without such training, work site risks are not detected, with potentially disastrous consequences. In September 2017, the only civilian ADAS level 3 and 4 training facility in Australia, The Underwater Centre Tasmania (TUCT), closed its doors. The reasons for TUCT closure were multifactorial. However, the loss of higher level training capability in this country and its benefits to industry will have a future adverse impact. As industry pushes for more complex diving to improve productivity, Australian occupational diver training processes are becoming 'streamlined' and are losing parity with international benchmarks. This is a potentially fatal combination.

[Correction of functional state of divers during training camps].

Correction of functional state of divers during training camps. The effect of a course of inhaled xenon-oxygen gas mixtures and audiovisual stimulation on the performance of the functional state of divers specialists in the process of intensive training camps is researched. It is shown that the combined use of them has a generally positive effect on the level of the functional state-diving professionals, increasing their individual resistance to adverse factors the complex military-professional environment. The results allow us to consider the combined use of these techniques as a promising means of surgical correction of the functional state of persons whose activities take place in conditions of considerable physical and psycho-emotional stress.

Insulin-dependent diabetes mellitus and recreational scuba diving in Australia.

Dive medicine bodies worldwide recognise that, with comprehensive screening and careful management, people with insulin-dependent diabetes (IDDM) can dive safely. Despite this, people with IDDM in Australia are generally denied access to dive training, an out-dated status quo that is not acceptable to the Australian diabetes community. This paper reflects upon the important advocacy work that has been done to progress this issue, and what is still required to open up access and bring Australia into line with more flexible and supportive international standards.

Representative learning design in springboard diving: Is dry-land training representative of a pool dive?

Two distinctly separate training facilities (dry-land and aquatic) are routinely used in springboard diving and pose an interesting problem for learning, given the inherent differences in landing (head first vs. feet first) imposed by the different task constraints. Although divers may practise the same preparation phase, take-off and initial aerial rotation in both environments, there is no evidence to suggest that the tasks completed in the dry-land training environment are representative of those performed in the aquatic competition environment. The aim of this study was to compare the kinematics of the preparation phase of reverse dives routinely practised in each environment. Despite their high skill level, it was predicted that individual analyses of elite springboard divers would reveal differences in the joint coordination and board-work between take-offs. The two-dimensional kinematic characteristics were recorded during normal training sessions and used for intra-individual analysis. Kinematic characteristics of the preparatory take-off phase revealed differences in board-work (step lengths, jump height, board depression angles) for all participants at key events. However, the presence of scaled global topological characteristics suggested that all participants adopted similar joint coordination patterns in both environments. These findings suggest that the task constraints of wet and dry training environments are not similar, and highlight the need for coaches to consider representative learning designs in high performance diving programmes.

Recreational technical diving part 1: an introduction to technical diving methods and activities.

Technical divers use gases other than air and advanced equipment configurations to conduct dives that are deeper and/or longer than typical recreational air dives. The use of oxygen-nitrogen (nitrox) mixes with oxygen fractions higher than air results in longer no-decompression limits for shallow diving, and faster decompression from deeper dives. For depths beyond the air-diving range, technical divers mix helium, a light non-narcotic gas, with nitrogen and oxygen to produce 'trimix'. These blends are tailored to the depth of intended use with a fraction of oxygen calculated to produce an inspired oxygen partial pressure unlikely to cause cerebral oxygen toxicity and a nitrogen fraction calculated to produce a tolerable degree of nitrogen narcosis. A typical deep technical dive will involve the use of trimix at the target depth with changes to gases containing more oxygen and less inert gas during the decompression. Open-circuit scuba may be used to carry and utilise such gases, but this is very wasteful of expensive helium. There is increasing use of closed-circuit 'rebreather' devices. These recycle expired gas and potentially limit gas consumption to a small amount of inert gas to maintain the volume of the breathing circuit during descent and the amount of oxygen metabolised by the diver. This paper reviews the basic approach to planning and execution of dives using these methods to better inform physicians of the physical demands and risks.

Recreational technical diving part 2: decompression from deep technical dives.

Technical divers perform deep, mixed-gas 'bounce' dives, which are inherently inefficient because even a short duration at the target depth results in lengthy decompression. Technical divers use decompression schedules generated from modified versions of decompression algorithms originally developed for other types of diving. Many modifications ostensibly produce shorter and/or safer decompression, but have generally been driven by anecdote. Scientific evidence relevant to many of these modifications exists, but is often difficult to locate. This review assembles and examines scientific evidence relevant to technical diving decompression practice. There is a widespread belief that bubble algorithms, which redistribute decompression in favour of deeper decompression stops, are more efficient than traditional, shallow-stop, gas-content algorithms, but recent laboratory data support the opposite view. It seems unlikely that switches from helium- to nitrogen-based breathing gases during ascent will accelerate decompression from typical technical bounce dives. However, there is evidence for a higher prevalence of neurological decompression sickness (DCS) after dives conducted breathing only helium-oxygen than those with nitrogen-oxygen. There is also weak evidence suggesting less neurological DCS occurs if helium-oxygen breathing gas is switched to air during decompression than if no switch is made. On the other hand, helium-to-nitrogen breathing gas switches are implicated in the development of inner-ear DCS arising during decompression. Inner-ear DCS is difficult to predict, but strategies to minimize the risk include adequate initial decompression, delaying helium-to-nitrogen switches until relatively shallow, and the use of the maximum safe fraction of inspired oxygen during decompression.

Managing scuba divers to meet ecological goals for coral reef conservation.

Marine protected areas increasingly are challenged to maintain or increase tourism benefits while adequately protecting resources. Although carrying capacity strategies can be used to cope with use-related impacts, there is little understanding of divers themselves, their management preferences, and how preferences relate to conservation goals. By using a stated preference choice modeling approach, we investigated the choices divers make in selecting diving trips to marine protected areas as defined by use level, access, level of supervision, fees, conservation education, and diving expectations. Logit models showed that divers preferred a more restrictive management scenario over the status quo. Divers favored reductions in the level of site use and increased levels of conservation education. Divers did not favor fees to access protected areas, having less access to the resource, or extensive supervision. Finally, divers were much more willing to accept increasingly restrictive management scenarios when they could expect to see increased marine life.

Toxicidad pulmonar asociada al empleo de oxígeno hiperbárico: procedimientos de cálculo / Pulmonary toxicity is associated with the hyperbaric oxygen: methods of calculation

OBJETIVOS: Estudiar si una exposición hiperbárica de larga duración motivada por la aparición de una enfermedad descompresiva bajo presión, presenta alteraciones espirométricas y si éstas están acompañadas de sintomatología clínica pulmonar compatible con toxicidad pulmonar por oxígeno. PACIENTES Y MÉTODO: 3 buceadores profesionales que durante una inmersión a 100 metros de profundidad, uno de ellos presenta, antes de terminar la inmersión una patología descompresiva que requiere aumentar los tiempos de respiración de oxígeno, se realizan espirometrías pre- y post-inmersión midiendo: FVC, FEV1, PEF, FEV1/FVC, FEF25-75, FEF 75-85, FEF 25, FEF 50, FEF 75. RESULTADOS: Los resultados post-inmersión demuestran un descenso global de todos los parámetros estudiados destacando el descenso de PEF (12.8%), FEF 50 (9,3%) y FEV1 (8.8%), de forma individual 2 buceadores mostraron descenso de todos los parámetros mientras que un buceador de los nueve parámetros estudiados solo experimentó descenso en cinco. Estos resultados no estuvieron acompañados de sintomatología pulmonar y carecieron de significado estadístico. CONCLUSIONES: Tras esta exposición hiperbárica se alteró el flujo y la capacidad sin la presencia de sintomatología clínica pulmonar y papel importante de la susceptibilidad individual. Los estudios de función pulmonar se deberían extender a colectivos sometidos a: cambios constantes de presión y a la respiración de oxígeno, gas con efectos tóxicos agudos y a largo plazo (AU)

INTRODUCTION: We studied if one hyperbaric exposition in the long term with decompression sickness under pressure causes disturbances in the pulmonary functions and if they are related with clinical manifestations which are compatibles with pulmonary oxygen toxicity. PATIENTS AND METHOD.-Three professional divers carried out one immersion at 100 meters of deep, only one person displayed, before the immersion was finished, one decompression pathology which need increase the times breathing of oxygen, we valued the pulmonary functions pre and post immersion so we measured: FVC, FEV1, PEF, FEV1/FVC, FEF25-75, FEF 75-85, FEF 25, FEF 50 and FEF 75. RESULTS: The post immersion results showed one total decline of all studied parameters showed the decrease of PEF (12.8%), FEF 50 (9.3%) and FEV1 (8.8%), two divers showed one decline of all parameters meanwhile that one diver registered decrease only in five parameters. These results are not accompanied of pulmonary symptoms and of significant statistic. CONCLUSIONS: After this hyperbaric exposure, the flow and the capacity were disturbed but they did not show neither clinic pulmonary symptoms nor had one important role in the personal susceptibility. The studies of pulmonary function should include group with constant pressure changes and the breathing of oxygen, this gas have acute toxic effects in the long term (AU)

[Health fitness assessment for recreational diving requires special medical competence]. / Hälsobedömning för sportdykning kräver medicinska specialkunskaper.

Recreational diving has become increasingly popular in Sweden over the last years and about half a million dives are made each year. During the same time the health requirements for diving have changed and today we allow asthmatics and diabetics to dive under certain conditions. Chest X-ray, that earlier was compulsory, is not required in the fitness to dive examination, and in the future Europe the minimal requirements will be a health declaration rather than a FTD examination by a doctor. Despite this there will be a need for doctors with competence in diving medicine to handle medical problems in connection to diving and to evaluate all the questions generated by the divers' answers in the health declarations.

Long term retention of safe diving skills.

This short report describes a 20-month follow-up of safe diving skills, extending the 8-month retention period previously published in this journal. Thirty-four recreational swimmers with poor diving skills were evaluated before and immediately after a diving skills intervention program. Twenty-two returned for the eight-month follow-up evaluation and 16 returned 20 months post. As with the earlier study, Treadwater, Deck, Block and Running dives were video-recorded, and maximum depth, distance, velocity, entry angle and flight distance were compared. Underwater hand and arm positions were examined. Pre-intervention, a breaststroke arm action before maximum depth occurred in 18% of all dives and 38% of Treadwater dives. This was eliminated post-intervention, improving head protection. The Treadwater dive elicited the greatest mean maximum depth, and ANOVA showed depth for this entry decreased (improved) following intervention and remained shallower at the eight-month and 20-month post follow-ups. The Block dive also became shallower following intervention while the Deck dive remained unchanged. As seven 10-minute skills sessions resulted in shallower dives with safer hand and arm positions, and these skills were retained over a 600 day non-practice period, it is reliable to consider that the inclusion of safe diving skills in learn-to-swim programs can provide a diving spinal cord injury prevention strategy.

Retention of safe diving skills.

This study investigated diving skill maintenance over an eight-month retention period following an intervention program. Thirty-four recreational swimmers with poor diving skills were measured before and immediately after a diving skills intervention program. Twenty-two returned for follow-up evaluation. Treadwater, Deck and Block dives were video-recorded, and maximum depth, distance, velocity, entry angle and flight distance were compared. Underwater hand and arm positions were examined. Pre-intervention, a breaststroke arm action before maximum depth occurred in 18% of all dives and 38% of Treadwater dives. This was eliminated post-intervention, improving head protection. The Treadwater dive elicited the greatest mean maximum depth, and ANOVA showed depth for this entry decreased (improved) following intervention and remained shallower at follow-up. Deck and Block dives also became shallower following intervention. As seven 10-minute skills sessions resulted in shallower dives with safer hand and arm positions, including safe diving skills in learn-to-swim programs can provide a diving spinal cord injury prevention strategy.

Risk reduction in diving spinal cord injury: teaching safe diving skills.

Thirty-four recreational swimmers underwent an intervention program to improve diving skills. Participants with low diving skills completed seven 10-minute sessions which emphasised locking thumbs and holding arms extended beyond the head, and steering and gliding skills. Various dive entries were video-recorded and maximum depth reached was used as the criterion measure. A one-way repeated measures analysis of variance was conducted for each dive condition. Maximum depth decreased for all dives. Velocity at maximum depth was greater for the Treadwater, Deck and Block conditions. Improved streamlining and increased 'spring' were evident in more confident participants. Hands separated in 71% of pre-intervention dives but only in 3% of post-intervention dives. Preintervention, arms were pulled backward before. or at, maximum depth in 30% of participants but none did this post-intervention. Diving skills were improved following participation in the intervention program.

Safe depths for teaching children to dive.

Eight stages commonly used to teach diving were analysed for peak vertical velocity; vertical velocity at and following water impact and at previously recommended minimum water depths; maximum depth reached; and relationship between vertical velocity and maximum depth attained at each stage; for 13 male and 13 female children aged 6-8 years. Comparisons of mean water impact vertical velocities and maximum depths attained revealed significantly lower impact vertical velocities (F[6] = 117.39, p < 0.0001) and maximum depths (F[6] = 36.59, p < 0.0001) when performing the sit dive compared to the reference standing dive. At other stages, subjects travelled faster than the critical head velocities shown to cause adult cervical spine damage when passing through previously recommended minimum water depths.