scientific-2018

Scientific papers 2018

In this document, Wienke & O'Leary attempt a short history of deep and shallow stops by taking into account physical aspects, staging differences, diving tests, models with data correlations, and data banks with user statistics. Pros and cons of deep and shallow stops are presented, and what they consider misfacts are righted. Also, they discuss the various tests, training agency standards, commercial diving operations, and dive software linked to this topic.

Authors: Alf O Brubakk, Randi Eidsmo Reinertsen, V. Flook, & S. Koteng Abstract: Reduction in ascent speed and an increase in the O2 tension in the inspired air have been used to reduce the risk for decompression sickness. It was previously reported that decompression speed and O2 partial pressure are linearly related to human decompressions from saturation hyperbaric exposures. The constant of proportionality K (K 5 rate/partial pressure of inspired O2) indicates the incidence of decompression sickness. This study investigated the relationship between decompression rate, partial pressure of inspired O2, and the number of central gas bubbles after a 3-h dive to 500 kPa while breathing nitrox with an O 2 content of 35 kPa.

Authors: Joe KS Leung, Rex PK Lam Hyperbaric oxygen therapy is widely accepted as a life- saving treatment for decompression illness. Yet, its use in acute carbon monoxide poisoning has remained controversial because of inconsistent findings in clinical trials. Hyperbaric oxygen therapy has an adjunctive role in managing gas gangrene, necrotising soft-tissue infection, and crush injury, as supported by the case series. Several cases have been reported in the literature detailing the use of hyperbaric oxygen therapy in patients with severe anemia in whom blood transfusion is not possible.

12 - Safety Priorities and Underestimations in Recreational Scuba Diving Operations: A European Study Supporting the Implementation of New Risk Management Programmes

Authors: Serena Lucrezi, Salih Murat Egi, Massimo Pieri, Francois Burman, Tamer Ozyigit, Danilo Cialon, Guy Thomas, Alessandro Marroni, and Melville Saayman. Scuba diving is an important marine tourism sector but requires proper safety standards to reduce the risks and increase accessibility to its market. To achieve safety goals, safety awareness and positive safety attitudes in recreational scuba diving operations are essential. However, there is no published research exclusively focusing on scuba divers’ and dive centres’ perceptions toward safety. This study assessed safety perceptions in recreational scuba diving operations, with the aim to inform and enhance safety and risk management programs within the scuba diving tourism industry.

Authors: Isaac Peña-Villalobos, Ignacio Casanova-Maldonado, Pablo Lois, & Catalina Prieto. This paper does not speak of diving but of hyperbaric oxygen therapy (HBOT) to solve diverse diseases, infections, and tissue injuries. However, this study highlights other therapeutic effects of oxygen than those commonly explained to divers. This study's authors analyze the effects of HBOT on specific aspects of tissue growth, maintenance, and regeneration to provide answers on how this treatment could benefit from combination with regenerative medicine strategies.

Authors: Fatima Z. Kiboub, Costantino Balestra, Øyvind Loennechen, Ingrid Eftedal. Saturation divers are exposed to elevated partial pressure of oxygen (ppO2) in their hyperbaric work environment. Experimental studies indicate that oxygen transport is altered, and the authors previously reported a drop in hematocrit and extensive downregulation of genes involved in blood oxygen transport capacity after decompression from professional saturation diving. This study investigates the initial period of hematological adjustment back to normobaric air after professional saturation diving.

Authors: Gerardo Bosco, Alex Rizzato, Luca Martani, Simone Schiavo, Ennio Talamonti, Giacomo Garetto, Matteo Paganini, Enrico M. Camporesi, and Richard E. Moon. The present study aimed to evaluate the partial pressure of arterial blood gases in breath-hold divers performing a submersion at 40 m. Eight breath-hold divers were enrolled for the trials held at the “Y-40 THE DEEP JOY” pool (Montegrotto Terme, Padova, Italy). Prior to submersion, an arterial cannula in the radial artery of the non-dominant limb was positioned. All divers performed a sled-assisted breath-hold dive to 40 m. Three blood samplings occurred: at 10 min prior to submersion, at 40 m depth, and within 2 min after diver’s surfacing and after resuming normal ventilation. Blood samples were analyzed immediately on site.

Authors: Jean-Eric Blatteau, Sandrine Gaillard, Sébastien De Maistre, Simone Richard, Pierre Louges, Emmanuel Gempp, Arnaud Druelles, Henri Lehot, Jean Morin, Olivier Castagna, Jacques H. Abraini, Jean-Jacques Risso, Circulating mitochondrial DNA (mtDNA) is receiving increasing attention as a danger-associated molecular pattern in conditions such as autoimmunity or trauma. In the context of decompression sickness (DCS), the course of which is sometimes erratic, the authors hypothesize that mtDNA plays a not insignificant role, particularly in neurological type accidents. This study is based on the comparison of circulating mtDNA levels in humans presenting with various types of diving accidents and punctured upon their admission at the hyperbaric facility.

Authors: Blair D. Johnson, Morgan C. O’Leary, Muhamed McBryde, James R. Sackett, Zachary J. Schlader, & John J. Leddy. The authors tested the hypothesis that concussed college athletes have attenuated parasympathetic and sympathetic responses to face cooling. The experimentations described in this document were not made with divers. However, the phenomenon described will happen when the face of the diver is exposed to cold water.

Authors: Gerardo Bosco, Alex Rizzato, Silvia Quartesan , Enrico Camporesi, Devanand Mangar, Matteo Paganini, Lorenzo Cenci, Sandro Malacrida, Simona Mrakic-Sposta, Sara Moretti, & Antonio Paoli. Central Nervous System Oxygen Toxicity (CNS-OT) is one of the most harmful effects of Enriched Air Nitrox (EAN) diving. Protective factors of the Ketogenic Diet (KD) are antioxidant activity, the prevention of mitochondrial damage, and anti-inflammatory mechanisms. This study investigated whether a short-term KD may reduce oxidative stress and inflammation during a hyperoxic dive.

Authors: Mikael Gennser, S. L. Blogg, Ola Eiken, and Igor B. Mekjavic Human extravehicular activity (EVA) is essential to space exploration and involves the risk of decompression sickness (DCS). On Earth, the effect of microgravity on physiological systems is simulated in an experimental model where subjects are confined to a 6 degres head- down bed rest (HDBR). This model investigated various resting and exercise regimens for forming venous gas emboli (VGE), an indicator of decompression stress, post- hyperbaric exposure.

Authors: BR Wienke and TR O’Leary The question of bubble regeneration and broadening in the diver under compression-decompression is virtually unanswered and untractable. Effects in vivo have not been measured nor quantified to date and remain unlikely soon. The authors take up this question and suggest hypothetical impacts on diver staging using available data and recent experimental results in the laboratory.

48 - Was the appearance of surfactants in air breathing vertebrates ultimately the cause of decompression sickness and autoimmune dicease?

Author: Ran arieli Pulmonary surfactants are surface-active lipoproteins deposited in clearly deﬁned areas on the luminal aspect of blood vessels. Bubbles nucleate and grow at these spots after decompression from high pressure. Proteins with hydrophobic regions circulating in the blood will adhere to the gas phase-plasma interface. Deformation of their secondary and tertiary conﬁguration will present them as foreign molecules or autoantigens. Components of the intact protein also present in a deformed protein may be recognized as foreign too.

Authors: Barbara E. Shykoff & John P. Florian This study examines differential effects of immersion, elevated oxygen partial pressure, and exercise on pulmonary function after series of five daily six-hour dives at 130 kPa (1.3 ATA), with 18 hours between dives.

Author: Pierre Boudinet The author of this study presents a new way of taking into account the dynamics of the gas phase during decompression. This study is based on the analysis of certain hypotheses underlying classical models using Maximal Values (M-Values). The author derives a reduced set of ordinary differential equations, depending only on three empirical parameters. After having explained how the theory is built, the author proposes some values of the parameters that match the known surface M-Values

15 - Acute Anxiety Predicts Components of the Cold Shock Response on Cold Water Immersion: Toward an Integrated Psychophysiological Model of Acute Cold Water Survival

Authors: Martin J. Barwood, Jo Corbett, Heather Massey, Terry McMorris, Mike Tipton, and Christopher R. D. Wagstaff Drowning is a leading cause of accidental death. In cold- water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs.

18 - Nitrogen narcosis induced by repetitive hyperbaric nitrogen oxygen mixture exposure impairs long-term cognitive function in newborn mice.

Authors: Bin Peng, Shun-Hua Peng, Run-Ming Qu, Li-Hua Xu, Zheng-Lin Jiang Human beings are exposed to compressed air or a nitrogen-oxygen mixture, they will produce signs and symptoms of nitrogen narcosis such as amnesia or even loss of memory, which may disappear once back to the normobaric environment. This study was designed to investigate the effect of nitrogen narcosis induced by repetitive hyperbaric nitrogen-oxygen mixture exposure on long-term cognitive function in newborn mice and the underlying mechanisms.

Authors: Carelli M, Laurino M, Zaccaro A, Lai E, Passera M, Gemignani A Nitrogen Narcosis is a reversible syndrome affecting divers performing deep dives breathing air. Symptoms go from euphoria, slow reasoning and reaction time, impaired motor coordination, to complete loss of consciousness. Symptoms severity increases as the nitrogen partial pressure increases, with depth. This document is a 1 page PDF designed to be displayed on a large screen

Authors: Pierre Lafère, Peter Germonpré, François Guerrero, Alessandro Marroni, Costantino Balestra 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.

Authors: Çigdem Özer Gökaslan, Ugur Toprak, Serkan Gokaslan High-pressure water injuries are usually seen in the extremities and less often in the thorax and abdominal areas. A literature review reveals a few case reports describing intra-abdominal injuries due to penetrating trauma. This paper presents the radiological findings of a rare case of abdominal wall injury without penetration of the peritoneum caused by a high-pressure water jet due to the Coanda effect. The Coanda effect is the tendency of a fluid jet to stay attached to a curve.

Authors: Gerardo Bosco, Alex Rizzato, Richard E. Moon, and Enrico M. Camporesi This paper illustrates the physiological changes induced by immersion, swimming, breath-hold diving and exploring while using special equipment in the water.

Authors: Giuseppe Accurso, Andrea Cortegiani, Sabrina Caruso, Oriana Danile, Domenico Garbo, Pasquale iozzo, Filippo Vitale, Santi Maurizio Raineri, Cesare Gregoretti, & Antonino Giarratano The authors report two episodes of Taravana syndrome occurred in the same young male spear fishing champion affected by hyperho-mocysteinemia treated with recompression treatment at the Hyperbaric Oxygen Therapy (HBOT) Department of the University Hospital Policlinico Paolo Giaccone, Palermo, Italy, in November 2010 and July 2016.

Authors: Q. Buzzacott, D. Schiller, J. Crain, and P. Denoble This study, published in 2018, investigated morbidity and mortality suffered by divers in the US and Canada.

Author: Ran Arieli Taravana is a neurological form of decompression illness (DCI) prevalent in repeated breath-hold diving. A nanobubble on an active hydrophobic spots (AHS) in a distal artery of the brain may receive an influx of nitrogen after each dive until it occludes the arterial blood flow. The vestibular organ has very low perfusion compared with the brain and the cochlea of the inner ear. The author suggests that a nanobbubble on an AHS in the distal artery of the vestibular organ will receive a high influx of nitrogen from the surrounding tissue after decompression due to the low nitrogen clearance, thus expanding to cause vestibular DCI.

Author: Alice Bliznyuk, Hava Golan, & Yoram Grossman Divers that are exposed to high pressure (HP) above 1.1 MPa suffer from High Pressure Neurological Syndrome (HPNS), which is implicated with central nervous system (CNS) malfunction. Marine mammals performing extended and deep breath-hold dives are exposed to almost 20 MPa without apparent HPNS symptoms. N-methyl-D-aspartate receptor (NMDAR) has repeatedly been implicated as one of the major factors in CNS hyperexcitability as part of HPNS. Electrophysiological studies in rat brain slices at He HP showed a significant increase in the synaptic NMDAR response, followed by postsynaptic excitability changes.

Authors: Thiago Felipe dos Santos Barros, Renata Gregorio Paulos, Fernanda do Carmo Iwase, Gustavo Bispo dos Santos, Marcelo Rosa de Rezende, Rames Mattar Júnior This study aims to evaluate histological changes in the peripheral nerves of rats after sciatic nerve neurorrhaphy, based on the duration of exposure to hyperbaric oxygen chamber treatment.

Authors: F. Gregory Murphy, Ashleigh J. Swingler, Wayne A. Gerth, Laurens E. Howle Decompression sickness (DCS) in humans is associated with reductions in ambient pressure that occur during diving, aviation, or certain human spaceflight operations. Probabilistic models of DCS allow predicting the probability of DCS occurrence and the time of occurrence during or after a given hyperbaric or hypobaric exposure, based on how the gas contents or gas bubble volumes in hypothetical tissue compartments vary during the exposure. These models are calibrated using data containing the pressure and inspired gas histories of real exposures.

Authors: Antonin Povolny, Hiroshige Kikura, & Tomonori Ihara The ultrasonic pulse-echo technique makes it possible to detect each bubble and measure the position of its surface accurately. However, it has only been used to measure individual bubbles so far. This paper investigates whether the pulse-echo technique can be used to measure multiple bubbles simultaneously.

Authors: Ahmed Mohammed Aldakhil, Abdullah Faraj Alshammari, Sattam Saad Alshammar This article aims to assess dental and temporomandibular joint (TMJ) problems in a sample of SCUBA divers in Jeddah, Saudi Arabia. This study assesses dental complaints and TMJ problems associated with SCUBA diving, as well as the correlation of previous problems with diving-related characteristics such as duration of practice, number of dives, and frequency of diving per month.

Authors: Pieter Jan AM van Ooij A relationship between body composition and DCS has been observed in dogs since the nineteenth century. In the author's experience, it was not always the overweight diver who ended up in the treatment chamber with DCS. Gender, age, physical fitness, and the presence of a patent foramen ovale (PFO) have all been studied as possible factors in the development of vascular gas bubbles and, therefore, DCS. However, none of these factors, alone or in combination, explains why there are intra-individual or intra-cohort differences in bubble grade.

Authors: Julien Hugon, Asya Metelkina, Axel Barbaud, Ron Nishi, Fethi Bouak, Jean-Eric Blatteau, Emmanuel Gempp This retrospective study reviewed data from 1,016 manned air dives, including dive parameters (depth, bottom time, and total ascent time), precordial and subclavian venous gas embolism grades (Kisman-Masurel) and post-dive decompression sickness status. The study analyzed the correlation between subclavian and precordial grades, as well as the association between the probability of decompression sickness (DCS) and dive parameters, including high bubble levels.

Author: B.R. Wienke The risks of decompression sickness associated with arbitrary ascents to depths above the diver and the risks of surfacing are not yet encoded in underwater equipment and diveware, and this is the focus here. Assessing risks is necessary for diver safety and sensible dive planning. The authors define and discuss exponential risk functions for dissolved gas and bubble models, specifically the end-of- dive (EOD) and on-the-fly (OTF) functions, using profile data correlated with a database

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Authors: Yeonsik Noh, Hugo F. Posada-Quintero, Yan Bai, Joseph White, John P. Florian, Peter R. Brink, and Ki H. Chon This study investigates the effects of prolonged and high- pressure SCUBA diving on the autonomic nervous system (ANS) by collecting and analyzing electrocardiogram (ECG) data from divers at different depths and using different gas mixes to understand how diving conditions affect cardiac ANS behaviour, with particular emphasis on the dynamics of sympathetic and parasympathetic activity. It details the methodology, including the use of a Holter monitor and a novel algorithm for ANS assessment, and presents results showing changes in parasympathetic and sympathetic activities under different diving conditions.

24 - Tirofiban, a Glycoprotein IIb/IIIa Antagonist, Has a Protective Effect on Decompression Sickness in Rats: Is the Crosstalk Between Plateletand Leukocytes Essential?

Authors: Kate Lambrechts, Sébastien de Maistre, Jacques H. Abraini, Jean-Eric Blatteau, Jean-Jacques Risso, and Nicolas Vallée This study investigates the effectiveness of antiplatelet drugs, specifically those targeting the GPIIb/IIIa integrin, in preventing decompression sickness (DCS) using a rat model. It aims to confirm that these drugs, particularly tirofiban (TIR), can improve clinical outcomes and reduce the incidence of DCS by limiting platelet activation and subsequent inflammatory responses. This study also raises questions about the potential drawbacks of inhibiting other integrins, such as alpha-V-beta-3 and alpha-Mbeta-2, which are involved in immune system communication..

Authors: Asadullah Naqvi, and Derrick Clarence This study highlights the complexities and diagnostic challenges associated with decompression illness (DCI) in scuba divers. It emphasizes the need to consider multiple possibilities and co-existing pathologies when diagnosing and treating patients and that DCI can present with atypical symptoms. Also, it describes the case of a 42-year- old male who experienced symptoms post-scuba diving, detailing the diagnostic and recovery processes and the role of a patent foramen ovale in exacerbating DCI.

Authors: Gerardo Bosco, Alex Rizzato, Silvia Quartesan, Enrico Camporesi, Simona Mrakic-Sposta, Sarah Moretti, Costantino Balestra, Alessandro Rubini This study investigates the effects of hyperbaric and hyperoxic exposure using scuba or closed-circuit rebreather (CCR) on divers to determine whether acute exposure to oxygen-enriched environments during diving affects respiratory performance and oxidative state, using spirometry and biomarkers of oxidative damage as measures. It concludes that oxidative stress increases with CCR use but does not impact pulmonary function.

10 - Extravascular Hydrophobic Surfaces, Fat Droplets, and the Connection With Decompression Illness: Spinal, Joint Pain, and Dysbaric Osteonecrosis.

Authors: Ran Arieli This paper provides a detailed scientific explanation of the mechanisms and conditions leading to decompression illness (DCI), particularly focusing on the formation and expansion of gas bubbles from nanobubbles in the body. It explains the physiological and biochemical processes involved, the potential sources of gas micronuclei, and the implications for different tissues and structures in the body.

Authors: Karl Shreeves, Peter Buzzacott, Al Hornsby, Mark Caney The authors of this document present the findings of a study that investigates the relationship between violations of accepted diving practices and diver fatalities to highlight the significance of medical events and safety violations in diving-related deaths, emphasizing the importance of physical fitness, regular medical checkups, and adherence to safe diving practices to reduce fatalities.

Authors: Ran Arieli This study investigates the relationship between violations of accepted diving practices and diver fatalities to highlight the role of medical events and safety violations in diving-related deaths, emphasizing the importance of physical fitness, regular medical checkups, and adherence to safe diving practices to reduce fatalities. It also provides statistical data and conclusions to support these recommendations.

07 - Variability in circulating gas emboli after a same scuba diving Exposure.

Author: V. Papadopoulou, P. Germonpré, D. Cosgrove, R. J. Eckersley, P. A. Dayton, G. Obeid, A. Boutros, M.-X. Tang, S. Theunissen, C. Balestra This study examined venous gas emboli (VGE) variation in 14 divers after standardized dives. Results showed significant differences between individuals in VGE detection and scores, with some divers showing varying results even on consecutive dives. More research is needed to understand these differences and improve detection methods for decompression stress.

08 - Extravascular Hydrophobic Surfaces, Fat Droplets, and the Connection With Decompression Illness: Spinal, Joint Pain, and Dysbaric Osteonecrosis.

Author: Ran Arieli Decompression bubbles form from existing gas micronuclei, which can grow into nanobubbles on lipid droplets during pressure changes. When these bubbles expand in rigid places like bones or joints, they can cause harm. Nanobubbles can form on hydrophobic surfaces in the body, potentially leading to DCI symptoms.

29 - Effects of sleep and fatigue on teams in a submarine environment

Authors: Sarah Chabal, Rebecca Welles, Lt.Cmdr. F. Jay Haran, Rachel Markwald Successful submarine operations depend on tactical teams working under fatigue. Sleep loss and circadian disruption cause this fatigue, but little is known about its effect on team performance in submarines. This review discusses factors in team fatigue research, the impact of sleep on submariners, the effects of individual fatigue, and its influence on team performance. Future research should focus on the relationship between sleep and team dynamics.

30 - The Gradient Perfusion Model Part 1: Why and at what sites decompression sickness can occur.

Authors: Michael B Strauss, Lientra Q Lu, Stuart S. Miller This first part of a series discusses the reasons and locations of DCS. Over 50 years and 500 cases, it became clear that most “unexplained DCS” cases have physiological reasons. Variability in tissue blood flow and pressure gradients contribute to bubble formation. The Gradient-Perfusion Model explains these cases, suggesting that the term “unexplained DCS” should be replaced with “disordering events.

31 - The Gradient Perfusion Model Part 2: Substantiation of the GPM with clinical cases.

Authors: Michael B Strauss, Lientra Q Lu, Stuart S. Miller Part 1 of this series explained why and where decompression sickness (DCS) happens using the Gradient-Perfusion Model (GPM). This 2nd part provides evidence and clinical cases previously labeled as “unexplained DCS,” which later showed disordering events as causes. 500 DCS cases over 50 years were reviewed, finding that some previously unexplained cases had identifiable causes. The results show that gradient- perfusion connections explain the clinical findings, suggesting that “unexplained DCS” should be replaced with “DCS due to disordered decompression”.

32 - The Gradient Perfusion Model Part 3: An extraordinary case of decompression sickness.

Author: Lientra Q Lu, Michael B Strauss, Stuart S. Miller Decompression sickness (DCS) can occur in unusual situations like breath-hold diving. A 72-year-old healthy Hispanic woman experienced lower-leg paralysis after using a homemade hyperbaric chamber. She was treated with hyperbaric oxygen therapy after reporting abdominal pain and paralysis. Following this treatment, she fully recovered. This case illustrates "disordered decompression," suggesting that a "steal" syndrome may have caused her symptoms by affecting blood flow to tissues.

33 - Blood Gene Expression and Vascular Function Biomarkers in Professional Saturation Diving.

Author: Fatima Z. Kiboub, Andreas Møllerløkken, Astrid Hjelde, Arnar Flatberg, Øyvind Loennechen, and Ingrid Eftedal This study looked at gene expression and certain blood markers related to blood vessel health. It involved 20 male divers, with 13 taking vitamin C and E supplements during dives that lasted 7 to 14 days. Blood was taken before and after saturation, showing changes in gene activity related to oxygen transport and immune response. Antioxidant supplements did not impact these changes, indicating the divers maintained balance through their natural defenses.

34 - Indices of Increased Decompression Stress Following Long- Term Bed Rest

Author: Mikael Gennser, S. L. Blogg, Ola Eiken, and Igor B. Mekjavic Human extravehicular activity (EVA) is important for space exploration and carries the risk of decompression sickness (DCS). Researchers used a head-down bed rest (HDBR) model to study how different resting and exercise regimens affect venous gas emboli (VGE) formation after hyperbaric exposure. Eight healthy men took part in five hyperbaric exposure interventions during HDBR. Results showed low VGE levels, but higher levels were found when HE occurred at the end of HDBR. Future studies need to explore reasons for these findings.

35 - Provocative decompression causes diffuse vascular injury in mice mediated by microparticles containing interleukin-1 Beta

Author: Stephen R. Thom, Veena M. Bhopale, Kevin Yu, and Ming Yang Provocative decompression leads to wide-ranging vascular injury in mice due to micro-particles carrying interleukin-1Beta. Research shows that during exposure to high pressure, these particles increase significantly, along with levels of inflammatory agents. Vascular damage appears two hours post-decompression and lasts for at least 13 hours. Blocking IL-1Beta reduces this damage, indicating its key role in the process.