scientific-2016

Scientific papers 2016

Authors: Yara Bernaldo de Quirós, Andreas Møllerløkken, Marianne B. Havnes, Alf O. Brubakk, Oscar González-Díaz, and Antonio Fernández. The pathophysiological mechanism of decompression sickness is not fully understood, but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript, the team studied the relationship between the presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing.

Authors: Vincent Souday, Nick J. Koning, Bruno Perez, Fabien Grelon, Alain Mercat, Christa Boer, Valérie Seegers, Peter Radermacher, Pierre Asfar The objective of this study was to test the hypothesis of whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression.

This short article deals with useful and modern bubble models used to stage divers to the surface and correlations, if and when they exist, with actual data, usually decompression sickness (DCS) outcomes across a limited spectrum of exposures. Many of the early (wet) tests were carried out by world Navies, later by hyperbaric chamber testing, and today also by statistical inference from downloaded computer profiles.

In 2015, a workshop on ultrasound in diving research was held in Sweden, at which 27 participants from 12 countries hammered out guidelines to provide better standardisation of methods for both Doppler and echocardiography bubble counts. These guidelines and two papers from the meeting are published in this issue. The guidelines complement those developed in 2014 for the echocardiographic investigation of persistent foramen ovale in divers.

21 - Correlation between Patent Foramen Ovale, Cerebral “Lesions” and Neuropsychometric Testing in Experienced Sports Divers: Does Diving Damage the Brain?

Authors: Costantino Balestra and Peter Peter Germonpré SCUBA diving exposes divers to decompression sickness (DCS). There has been considerable debate whether divers with a Patent Foramen Ovale of the heart have a higher risk of DCS because of the possible right-to-left shunt of venous decompression bubbles into the arterial circulation. Symptomatic neurological DCS has been shown to cause permanent damage to the brain and spinal cord tissue; it has been suggested that divers with PFO may be at higher risk of developing subclinical brain lesions because of repeated asymptomatic embolization of decompression-induced nitrogen bubbles. These studies however suffer from several methodological faws, including self-selection bias.

Authors: Eugene V. Golanov, James M. Shiflett, Gavin W. Britz Diving response (DR) is a powerful integrative response targeted toward survival of the hypoxic/anoxic conditions. Being present in all animals and humans, it allows for surviving adverse conditions like diving. Earlier, the authors discovered that forehead stimulation affords a neuroprotective effect, decreasing infarction volume triggered by permanent occlusion of the middle cerebral artery in rats. The authors hypothesized that cold stimulation of the forehead induces DR in rats, which, in turn, exerts neuroprotection.

Authors: Joost J. L. M. Bierens, Philippe Lunetta, Mike Tipton, & David S. Warner. Knowledge of drowning physiology is scarce. A better understanding may identify methods to improve survival, particularly hot-water immersion, cold shock, cold-induced physical incapacitation, and fear of drowning.

35 - Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial.

Authors: Vincent Souday, Nick J. Koning, Bruno Perez, Fabien Grelon, Alain Mercat, Christa Boer, Valérie Seegers, Peter Radermacher, Pierre Asfar. This document relates tests performed regarding the hypothesis of whether enriched air nitrox (EAN) breathing during diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression.

16 - Nutritional considerations during prolonged exposure to a confined, hyperbaric, hyperoxic environment: recommendations for saturation divers.

Authors: S. K. Deb 1,2 , P. A. Swinton 1 and E. Dolan Saturation diving is an occupation that involves prolonged exposure to a confined, hyperoxic, hyperbaric environment. The unique and extreme environment is thought to disrupt physiological and metabolic homeostasis, which may impact human health and performance. Appropriate nutritional intake has the potential to alleviate and/or support many of these physiological and metabolic concerns while enhancing health and performance in saturation divers. Therefore, this review aims to identify the physiological and practical challenges of saturation diving and provide evidence- based nutritional recommendations for saturation divers to promote health and performance within this challenging environment.

39 - Pre-dive whole-body vibration better reduces decompression- induced vascular gas emboli than oxygenation or a combination of both

Authors: Costantino Balestra, Sigrid Theunissen, Virginie Papadopoulou, Cedric Le Mener, Peter Germonpré, François Guerrero, and Pierre Lafère Since non-provocative dive profiles are no guarantor of protection against decompression sickness, novel means, including pre-dive “preconditioning” interventions, are proposed for its prevention. This study investigated and compared the effect of pre-dive oxygenation, pre-dive whole-body vibration, or a combination of both on post- dive bubble formation.

02 - Fluoxetine Protection in Decompression Sickness in Mice is Enhanced by Blocking TREK-1 Potassium Channel with the “spadin” Antidepressant

Authors: Nicolas Vallée, Kate Lambrechts, Sébastien De Maistre, Perrine Royal, Jean Mazella, Marc Borsotto, Catherine Heurteaux, Jacques Abraini, Jean-Jacques Risso, and Jean-Eric Blatteau This study was to analyze the states of mental fatigue based on electroencephalography (EEG) and investigate how physical activities affect mental fatigue. Fourteen healthy participants participated in an experiment including a 2-back mental task (the control) and the same mental task with cycling simultaneously (physical-mental task).

Authors: Jacques H. Abraini, Hélène N. David, Nicolas Vallée, Jean- Jacques Risso The occurrence of paroxysmal narcotic episodes including psychotic-like symptoms in divers participating in experimental deep diving programs with various gas mixtures has constituted, beyond the classical symptoms of the high-pressure neurological syndrome, the major limitation for deep diving. With the development of new saturation deep diving programs and experiments by the eastern nations, such as India and China, the authors believed that it is of interest to examine what could be the ultimate depth that could be reached by saturation human divers.

14 - Symptomatic middle ear and cranial sinus Barotraumas as a complication of hyperbaric oxygen treatment.

Authors: Bengüsu Mirasoglu, Aslıcan Cakkalkurt, Maide Cimsit Hyperbaric oxygen therapy (HBOT) is applied to various diseases. It is generally considered safe but has some benign complications and adverse effects. The most common complication is middle ear barotrauma. This study aimed to collect data about the middle ear and cranial sinus barotraumas in our department and to evaluate factors affecting the occurrence of barotrauma.

Authors: John P. Florian, Ki H. Chon, Luca Faes & Barbara E. Shykoff Physiological compensation to postural stress is weakened after long-duration water immersion (WI), thus predisposing individuals to orthostatic intolerance (*orthostatic refers to the inability to remain upright without symptoms). This study was conducted to compare hemodynamic responses to postural stress following exposure to WI alone (Air WI) and hyperbaric oxygen alone in a hyperbaric chamber (O 2 HC). WI combined with hyperbaric oxygen (O2 WI), all at a depth of 1.35 ATA, to determine whether hyperbaric oxygen is protective of orthostatic tolerance

Authors: Ruben Vandenbulcke, Bartel van Holsbeeck, Ilse Crevits, and Jesse Marrannes A 58-year-old woman visited our hospital’s emergency department because of severe and increasing pain over the right occipital region, irradiating over the right frontal area. The pain started during the descent of a jet airplane on a holiday trip. There were no visual or hearing deficits, head trauma, or epistaxis, and she experienced no difficulty clearing her ears during the flight. Only a minor respiratory tract infection was noted two weeks before this episode, and she had no history of sinus problems. The pain was nothing like the previous migraine headaches she had experienced.

Authors: Jinqiang Zhu, Wanshan Song, Lin Li, and Xiang Fan. Endothelial nitric oxide (NO) is a significant signaling molecule that regulates cerebral blood flow (CBF), playing a pivotal role in the prevention and treatment of cerebrovascular diseases. However, achieving the expected therapeutic efficacy is difficult using direct administration of NO donors. Therefore, endothelial nitric oxide synthase (eNOS) becomes a potential therapeutic target for cerebrovascular diseases. This review summarizes the current evidence supporting the importance of CBF to cerebrovascular function, and the roles of NO and eNOS in CBF regulation.

Authors: Ben Aviner, Gideon Gradwohl, Alice Bliznyuk, Yoram Grossman Exposure to hyperbaric pressure (HP) exceeding 100 msw is known to cause a constellation of motor and cognitive impairments named high-pressure neurological syndrome (HPNS), considered to be the result of synaptic transmission alteration. Previous studies have indicated the modulation of presynaptic Ca2+ currents based on synaptic activity modified by HP. The authors shown that currents in genetically identified cellular voltage- dependent Ca2+ channels selectively affected by HP.

Authors: Jacky Lautridou, Vianney Pichereau, Sebastien Artigaud, Peter Buzzacott , Qiong Wang , Benoit Bernay, Sabrina Driad, Aleksandra Mazur, Kate Lambrechts, Michael Theron, & Francois Guerrero Decompression sickness (DCS) is a poorly understood systemic disease caused by inadequate desaturation following a reduction in ambient pressure. Although studies highlight the importance of circulating factors, the available data are still puzzling. In this study, we aimed to identify proteins and biological pathways involved in the development of DCS in rats.

Authors: D. Cialoni, M. Pieri, G. Giunchi, N. Sponsiello, A.M Lanzone, L. Torcello, G. Boaretto, A. Marroni Neurological symptoms after breath hold (BH) diving are often referred to as “Taravana” and considered a form of decompression sickness. However, the presence of “high” gas embolism after BH diving has never been clearly shown. This study showed high bubble formation after breath hold diving.

22 - Effects of heated and humidified high flow gases during high-intensity constant-load exercise on severe COPD patients with ventilatory limitation

Authors: Serena Cirio, Manuela Piran, Michele Vitacca, Giancarlo Piaggi, Piero Ceriana, Matteo Prazzoli, Mara Paneroni, Annalisa Carlucci) This document is to be read as support for the problem posed by too dry air and the importance of humidity in breathing.

25 - High Pressure and [Ca2+] Produce an Inverse Modulation of Synaptic Input Strength and Network Excitability in the Rat Dentate Gyrus

Authors: Thomas I. Talpalar, & Adolfo E. Talpalar Hyperbaric environments induce the high pressure neurological syndrome (HPNS) characterized by hyperexcitability of the central nervous system (CNS) and memory impairment. High pressure depresses synaptic transmission and alters its dynamics in various animal models. Medial perforant path (MPP) synapses connecting the medial entorhinal cortex with the hippocampal formation are suppressed by 50% at 10.1MPa. Reduction of synaptic inputs is paradoxically associated with enhanced ability of dentate gyrus (DG)’ granule cells (GCs) to generate spikes at high pressure.

Authors: Hilary F. Armstrong, Gina S. Lovasi, Elsayed Z. Soliman, Susan R. Heckbert, Bruce M. Psaty, John H.M. Austin, Jerry A. Krishnan, Eric A. Hoffman, Craig Johnson, Matthew J. Budoff, Karol E. Watson, R. Graham Barr Studies suggest an association between chronic obstructive pulmonary disease (COPD) and prolonged QT interval*. The authors tested the hypotheses that lower lung function and increased percent emphysema on computed tomography (CT) are associated with a prolonged QT interval in a general population sample and additionally in those with chronic obstructive pulmonary disease. *QT interval is a measurement made on an electrocardiogram (ECG) used to assess some of the electrical properties of the heart.

Authors: Ozturk Handan and Aktas Samil The authors of this short article explain the definition of hyperbaric oxygen therapy (HBOT) in response to a previous article titled "Pressure Ulcers: Current Understanding and Newer Modalities of treatment”, published in January 2015. (See the article below)

Authors: John W. Castellani, Andrew J. Young This paper reviews and discusses humans' physiological responses to cold exposure, both acute and chronic, and the external factors that influence these responses. It provides an overview of the mechanisms involved in maintaining thermal balance during cold exposure and describes the different patterns of acclimatization that occur with chronic exposure to cold environments.

Authors: Julie Vinkel, Peter Bak and Ole Hyldegaard This document reports 33 fatal diving injuries that occurred among Danish divers during the period 1999 - 2012 in Scandinavian waters. The study was performed as a retrospective overview. The empirical data consists of police reports, forensic autopsy reports, and examination of the diving equipment. The data were assembled and analyzed using Pivot and Excel. Frequencies and means were used to describe categorical and continuous variables, respectively.

Authors: Susannah Sherlock, Kenneth Thistlethwaite, Mohsina Khatun, Christopher Perry, and Alexis Tabah This paper is a retrospective audit of outcomes in patients treated with hyperbaric oxygen (HBOT) for idiopathic sudden sensorineural hearing loss (ISSHL), either as adjunctive treatment or after the failure of steroid therapy.

Authors: Akeelesh Mungur, Guy Cochard, Yves Ozier and Pierre Lafère The most common complications of hyperbaric oxygen treatment (HBOT) are related to pressure changes on gas- containing cavities. Therefore, the inability to auto-inflate the middle ear may result in transient or permanent hearing loss. However, it seems that middle ear barotrauma (MEBt) does not develop more often in mechanically ventilated patients than in ambulatory patients. This might be explained by the deep sedation of these patients. Therefore, the aim of this study was to determine whether anesthesia and/or neuromuscular blockade can influence Eustachian tube (ET) function.

Authors: Nikolaj Hjort Schmidt, Kasper Hansen, Henrik Lauridsen, Annie Vesterby, Jens Randel Nyengaard, Alf Brubakk, and Michael Pedersen Vascular bubble formation after decompression has been associated with inflammation, necrosis, and platelet activation. This study evaluates remote ischaemic conditioning (RIC), performed before or after decompression, on bubble formation, platelet activation, and ischaemic brain lesions.

33 - A day in the life of a diabetic diver: the Undersea and Hyperbaric Medical Society/Divers Alert Network protocol for diving with diabetes in action

Authors: Rebecca Johnson Some people with well-managed insulin-dependent diabetes can dive safely. Those cleared to participate should tightly control the variables that impact blood glucose levels, including activity, timing, food, and insulin. Honest self-assessment is critical.

Authors: Münïre Kübra Özgök-Kangal, Iclal Karatop-Cesur, Gökhan Akcalı, Senol Yildiz, and Günalp Uzun Carbon monoxide (CO) poisoning is common in Turkey. The authors’ department is the primary provider of emergency hyperbaric oxygen therapy (HBOT) in Ankara and neighboring cities. In this study, they analyzed the characteristics of CO-poisoned patients who were referred by phone to our department for emergency HBOT.

Authors: Rebecca Johnson Dive medicine bodies worldwide recognize that with comprehensive screening and careful management, people with insulin-dependent diabetes mellitus (IDDM) can dive safely. Despite this, it remains extremely difficult for people with IDDM to access diving training in Australia. People with IDDM are denied information, support, and access to training courses, which drives some to choose not to declare their condition or to travel overseas to certify as divers, which is both unsafe and unfair.

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05 - Dive, food, and exercise effects on blood microparticles in Steller sea lions (Eumetopias jubatus): exploring a biomarker for decompression sickness.

Authors: Andreas Fahlman, Michael J. Moore, Andrew W. Trites, David A. S. Rosen, Martin Haulena, Nigel Waller, Troy Neale, Ming Yang, and Stephen R. Thom New research suggests that military sonar may cause decompression sickness in marine mammals. Scientists tested whether blood microparticles could be used as a biomarker for this condition in Steller sea lions. Blood samples were taken from the sea lions after diving to predetermined depths, and it was found that diving caused an increase in blood microparticle levels. However, the levels did not correlate with depth or time underwater, suggesting acclimation to repeated exposure. Feeding and exercise had no effect on the levels of microparticles in the blood.

Authors: Andreas Mollerlokken, Lesley BIOQQ. David J Doolette, Ronald Y Nishi, & Neal W Pollock The International Meeting on Ultrasound for Diving Research issued expert recommendations for detecting vascular gas bubbles via ultrasound and for analyzing, interpreting, and reporting this data. They suggested standardizing methods such as choosing bubble monitoring sites, and the timing and duration of monitoring, using scales such as Spencer, Kisman-Masurel, or Eftedal-Brubakk. For reporting, they advised describing the subject's posture and any provocation maneuvers during monitoring, reporting raw data, and using statistics properly.

Authors: Mark D. Wilkinson et al. Data management is essential for scientists and diving companies. Stakeholders from academia, industry, funding agencies, and scholarly publishers have developed the FAIR Data Principles to improve the infrastructure for reusing scholarly data. These principles focus on enhancing machine automation to find and use data while also supporting individual reuse. This publication introduces the FAIR Principles, discusses their purpose, and provides examples of their implementation in the community.

Authors: National Aeronautics and Space Administration (NASA) - USA This document highlights issues related to space activities that should be considered for divers traveling by air. Divers, pilots, or astronauts moving from high to low- pressure environments can be affected by decompression sickness (DCS). This problem has been addressed since early space missions through pre-breathing (PB) protocols involving oxygen-rich environments and various pre- launch procedures. While effective, these methods are complex and require extensive training and resources.

32 - Neurologic Deep Dive: A Simulation Case of Diagnosing and Treating Decompression Sickness for Emergency Medicine Residents

Authors: Xiao C. Zhang, Antoinette Golden, David S. Bullard During a simulation exercise, emergency medicine residents managed a case of a patient with DCS, who presented with unilateral neurological symptoms and concealed cyanotic mottling. The simulation was run four times, with residents, fellows, and attendings taking on different roles. After the simulation, both junior and senior residents performed correctly. However, junior residents had difficulty gathering social history and examining the patient without senior guidance, and were less proficient in directing specific treatments such as oxygenation and hydration.

01 - Enriched air nitrox breathing reduces venous gas bubbles after simulated SCUBA Diving: A double-blind cross-over randomized trial

08 - Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

Authors: Paul F. McCulloch, Erik A. Warren and Karyn M. DiNovo This study investigates the role of the anterior ethmoidal nerve (AEN) in the diving response of rats to determine whether the AEN is necessary for initiating the diving response by examining the activation of specific brainstem nuclei during repetitive trained diving. The research involves comparing rats with bilateral sectioning of the AEN to those with a Sham surgery and analyzing the presence of Fos-positive neurons as a marker of neuronal activation. The findings suggest that the AEN is not required for the diving response, indicating that other nerves or suprabulbar activation may be responsible for the observed neuronal activation.

Authors: Wen-wu Liu, Cui-hong Han, Pei-xi Zhang, Juan Zheng, Kan Liu, Xue-jun Sun This paper summarizes and analyzes the role of nitric oxide (NO) in the pathogenesis of hyperoxic acute lung injury (HALI) and discusses the therapeutic potential of inhaled NO in treating HALI to inform readers about the current understanding and controversies surrounding the involvement of NO in HALI and highlight its potential as a treatment option.

Authors: Olivier Castagna, Emmanuel Gempp, Raphael Poyet, Bruno Schmid, Anne-Virginie Desruelle, Valentin Crunel, Adrien Maurin, Romain Choppard, and David H. MacIver This study investigated the relationship between altered cardiac function and the development of interstitial pulmonary edema in scuba divers. It involved measuring various cardiac and pulmonary parameters before and after a 30-minute scuba dive to understand how changes in heart function might contribute to the onset of pulmonary edema. The results suggest that an imbalance in right and left heart stroke volumes could be a key factor in the development of immersion pulmonary edema, with broader implications for understanding the pathogenesis of cardiogenic pulmonary edema.

Authors: Sebastian Klapa, Johannes Meyne, Wataru Kahler, Frauke Tillmans, Henning Werr, Andreas Binder, & Andreas Koch This document discusses a medical case involving a 61- year-old male who experienced severe hypovolemia and decompression illness (DCI) after diving. It highlights the relationship between hypovolemia and DCI, describes the patient's symptoms and diagnostic findings, and emphasizes the importance of early hyperbaric oxygen therapy and fluid replacement in achieving a favorable outcome.

Authors: John Lippmann, David McD Taylor, Christopher Stevenson and Simon Mitchell This paper presents the findings of a study that examines the demographics, health, and diving activities of members of the Diver Alert Network Asia-Pacific (DAN AP) with and without certain medical conditions (cardiac or respiratory conditions, diabetes, or hypertension). The authors compare these two groups to understand the impact of these medical conditions on diving practices and to highlight the need for better education and monitoring of health status among divers, particularly as they age.