scientific-2017

Scientific papers 2017

This article describes the various dermatoses that can be contracted during occupational and recreational diving.

02 - A comparative evaluation of two decompression procedures for technical diving using inflammatory responses: compartmental versus ratio deco. Authors: E. Spisni, C. Marabotti, S. Brambilla, M. C. Valerii, E. Cavazza, K. Hoxha ,L. De Fazio, A. L’Abbate, & P. Longobardi.

This study aimed to compare two decompression procedures commonly adopted by technical divers: The ZH-L16 algorithm, modified by 30/85 gradient factors (compartmental decompression model, CDM) versus the ‘ratio decompression strategy’ (RDS). The comparison was based on an analysis of changes in diver circulating inflammatory profiles caused by decompression from a single dive.

Authors: Thijs T. Wingelaar, Pieter-Jan A. M. van Ooij, and Rob A. van Hulst. In Special Operations Forces (SOF) closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2) could cause damage to the central nervous system (CNS) and pulmonary system. Longer exposure time and higher PO2 lead to faster development of more serious pathology.

Authors: István Vadász & Jacob I. Sznajder This review discusses recent discoveries on the sensing and signaling events initiated by hypoxia and hypercapnia and the relevance of these results in the identification of potential novel therapeutic targets in the treatment of acute respiratory distress syndrome (ARDS).

Authors: Pierre Lafère, Costantino Balestra, Dirk Caers, Peter Germonpré. The authors have crossed information from Belgian Hyperbaric Centers, DAN. Emergency Hotline, the press, and Internet diving forums to consider the majority of decompression sickness (DCS) occurred in Belgium from January 1993 to June 2013. From the available 594 records, the authors excluded all cases with tentative diagnosis, medullary DCS, or unreliability of reported dive profile, leaving 209 divers records with cerebral DCS for analysis. Dive parameters and patent foramen ovale (PFO) were recorded. Twenty-three injured divers were tested using the Zuckerman’s Sensation Seeking Scale V and compared to a matched group not involved in risky activities.

Authors: Peter Germonpré, Costantino Balestra, Walter Hemelryck, Peter Buzzacott, Pierre Lafère. This double-blinded, randomized trial was designed to see if using Enriched Air Nitrox (EANx) could improve cognitive performance while diving. Eight volunteers performed two no-decompression dry dives breathing air or EANx for 20 min at 0.4 MPa. Their cognitive functions were assessed with a computerized test battery. Measurements were taken before the dive, upon arrival, after 15 min at depth, upon surfacing, and at 30 min postdive. After each dive, subjects were asked to identify the gas they had just breathed..

35 - Dive Risk Factors, Gas Bubble Formation, and Decompression Illness in Recreational SCUBA Diving: Analysis of DAN Europe DSL Data Base.

Authors: Danilo Cialoni, Massimo Pieri, Costantino Balestra, Alessandro Marroni The popularity of SCUBA diving is steadily increasing, together with the number of dives and correlated diseases per year. The rules that govern correct decompression procedures are considered well known even if the majority of Decompression Sickness (DCS) cases are considered unexpected, confirming a bias in the “mathematical ability” to predict DCS by the current algorithms. Furthermore, little is still known about diving risk factors and any individual predisposition to DCS. This study provides an in-depth epidemiological analysis of the diving community to includeadditional risk factors correlated with circulating bubbles and DCS development.

Authors: Heather Massey, John Leach, Michael Davis, & Vicki Vertongen. In most countries, immersion represents the second most common cause of accidental death in children and the third in adults. Between 2010 and 2013, 561 deaths worldwide involving recreational divers were recorded by the Divers Alert Network. Consequently, there is no room for complacency when diving. Being lost at sea is a diver’s worst nightmare. In 2006, a diver was lost at sea off the coast of New Zealand for 75 hours. It is unprecedented that, after such a long time immersed in temperate (16−17 ° C) waters, he was found and survived. His case is presented and utilized to illustrate the many physiological and psychological factors involved in prolonged immersion and what might determine survival under such circumstances. The authors also briefly review options for enhancing diver location at sea, and a few issues related to search and rescue operations are discussed.

Authors: Anne-Kathrin Brebeck, Andreas Deussen, Henning Schmitz-Peiffer, Ursula Ranged, Costantino Balestra, Sinclair Cleveland, and Jochen D. Schipke. This study compares the effects of nitrox28 and air on two psychometric tests. In this double-blind, open-water study, 108 advanced divers were randomized to air or a nitrox group for a 60-min dive to 24 m saltwater. Breathing gas effects on cognitive performances were assessed during the dive using a short and long-term memory test and a number connection test.

Authors: Alvhild Alette Bjørkum, Eystein Oveland, Linda Stuhr, Marianne Bjordal Havnes, Frode Berven, Marit Grønning, Arvid Hope. The main objective of the present study was to determine the effects on the brain proteome of fast decompression (1 bar/20 s) compared to controls (1 bar/10 min) after heliox saturation diving, using rats in a model system.

Authors: Shopov Nikola, VazharovIvaylo. The most likely factor initiating Decompression Sickness (DCS) is believed to be the formation of bubbles in the blood and the tissues. Bubbles form during decompression due to supersaturation of the dissolved gas from the gas nuclei present in the tissues even at normal atmospheric pressure and provoke the symptoms of DCS. Ascent rate is known to be a critical factor for DCS risk. Individual factors, such as age, weight, and fat tissues, are also recognized for their implication in DCS risk. This study aimed to contribute to enhanced safety of divers by measuring the rate of off-gassing utilizing Doppler after decompression and relating it to ascent rate and some individual factors.

Authors: Seol-Jung Kang, Gi-Chul Ha, & Kwang-Jun Ko. The present study aimed to investigate the association between metabolic syndrome and cardiorespiratory fitness according to the resting heart rate of Korean male adults..

Authors: Peter Germonpré & Costantino Balestra. Vascular gas emboli (VGE) are observed after asymptomatic scuba dives and are considered a key element in the potential development of decompression sickness (DCS). Diving is also accompanied by vascular dysfunction, as measured by flow-mediated dilation (FMD). Previous studies showed significant intersubject variability to VGE for the same diving exposure and demonstrated that VGE could be reduced with even a single pre-dive intervention. Several preconditioning methods have been reported recently, seemingly acting either on VGE quantity or inflammatory endothelial markers.

Authors: C. Walsh, N. Ovenden, E. Stride, & U. Cheemat. Understanding cell-bubble interactions is crucial for preventing bubble related pathologies and harnessing their potential therapeutic benefits. Bubbles can occur in the body as a result of therapeutic intravenous administration, surgery, infections or decompression. Subsequent interactions with living cells, may result in pathological responses such as decompression sickness (DCS). This work investigates the interactions that occur between bubbles formed during decompression and cells in a 3D engineered tissue phantom.

32 - Nanobubbles Form at Active Hydrophobic Spots on the Luminal Aspect of Blood Vessels: Consequences for Decompression Illness in Diving and Possible Implications for Autoimmune Disease - An Overview

Author: Ran Arieli It is known that nanobubbles form spontaneously when a smooth hydrophobic surface is submerged in water containing dissolved gas. These nanobubbles may be the long-sought-after gas micronuclei underlying decompression bubbles and DCI. The authors exposed hydrophobic and hydrophilic silicon wafers underwater to hyperbaric pressure. After decompression, bubbles appeared on the hydrophobic but not the hydrophilic wafers. In further experiments, the authors placed sizeable ovine blood vessels in a cooled high-pressure chamber at 1,000 kPa for about 20 h.

Authors: Br Vienke & T O’ Leary This short monogram details dive computers, operation, protocols, models, data, tests, risk and coupled applications. Basic diving principles are detailed with practical computer implementations. Topics are related to diving protocols and operational procedures. Tests and correlations of computer models with data are underscored. The exposition also links phase mechanics to decompression theory with equations used in computer syntheses.

Authors: Long Qing, Dinesh K. Ariyadewa, Hongjie Yi , Yewei Wang, Quan Zhou, and Weigang Xu. Skin lesions are visual clinical manifestations of decompression sickness (DCS). Comprehensive knowledge of skin lesions would give simple but strong clinical evidence to help diagnose DCS. The aim of this study was to systematically depict skin lesions and explore their pathophysiological basis in a swine DCS model.

Authors: Dor Vadas , Leonid Kalichman, Amir Hadanny , and Shai Efrati The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, < 10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities.

14 - Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment

Authors: Daniel Mathieu, Alessandro Marroni and Jacek Kot The tenth European Consensus Conference on Hyperbaric Medicine took place in April 2016, attended by a large delegation of experts from Europe and elsewhere. The focus of the meeting was the revision of the European Committee on Hyperbaric Medicine (ECHM) list of accepted indications for hyperbaric oxygen treatment (HBOT), based on a thorough review of the best available research and evidence-based medicine (EBM)

Author: Barbara Shykoff This text has been published on the Shearwater website in May 2017 https://www.shearwater.com/ Direct link: https://www.shearwater.com/monthly-blog- posts/uptd-calculations-not-used/

Authors: Charles H. Van Wijk, Jarred H. Martin, Willem A.J. Meintjes This paper considers the relationship between measures of personality and mood states and susceptibility to inert gas narcosis. It briefly reviews the topics of inert gas narcosis affecting personality and personality affecting the susceptibility to inert gas narcosis. There appears to be a theoretical argument for a possible relationship between measures of personality, mood states, and susceptibility to narcosis. Practically, such a relationship may speak to selection, training and preparation issues, risk assessments, and even accident investigation in the diving and/or hyperbaric environment.

Authors: Sara Farshchi Zarabi, Matteo Parotto, Rita Katznelson, James Downar Air embolism into the systemic arterial circulation secondary to pulmonary barotrauma has rarely been reported. Herein, we report the clinical course of an extremely rare presentation of cerebral air embolism likely due to ruptured pulmonary bullae during commercial air travel.

Authors: Moritz F Meyer, Manuela Boor, Stefanie Jansen, Eberhard D Pracht , Moritz Felsch, Heinz D Klünter, Karl-Bernd Hüttenbrink, Dirk Beutner, Maria Grosheva In a prospective, observational trial, the authors investigated the feasibility of using the Eustachian tube function test (ETFT) to measure the effect of repetitive pressure exposure during open seawater dives on Eustachian tube function.

Authors: Moritz F Meyer, Manuela Boor, Stefanie Jansen, Eberhard D Pracht , Moritz Felsch, Heinz D Klünter, Karl-Bernd Hüttenbrink, Dirk Beutner, Maria Grosheva In a prospective, observational trial, the authors investigated the feasibility of using the Eustachian tube function test (ETFT) to measure the effect of repetitive pressure exposure during freshwater dives on Eustachian tube function.

Authors: Mark J Elder, John A Rawstron, Michael Davis Acute Retinal Artery Occlusion (ARAO) is a significant cause of sudden, painless visual loss, often leaving no useful vision in the affected eye. Its incidence is cited at 0.85 per 100,000 persons per year but may be higher because of under-reporting. The natural history is difficult to study, but a spontaneous resolution rate of < 1–8% for acute, non-arteritic ARAO has been cited. There is currently no consensus regarding the management of ARAO and little evidence to support any treatment modality. Despite only a limited case series, hyperbaric oxygen treatment (HBOT) is recommended for ARAO by the Undersea and Hyperbaric Medical Society (UHMS) and the European Committee for Hyperbaric Medicine.

Author: Charles H Van Wijk This paper provides a brief overview of the shift from studies describing the personality profiles of divers to studies exploring associations between personality variables and diving performance in terms of behavioural outcomes.

Author: Abraham L Querido Psychoactive drugs pose a risk to both the diver and his or her buddy. Little is known about the safety of diving with antidepressants. Amongst the potential interactions with the diving environment are: somnolence; convulsions; a bleeding tendency (potentially worsening decompression illness, DCI), alterations to glucose metabolism and psychiatric side effects. Fluoxetine may potentially reduce the inflammatory process associated with DCI. This article presents guidelines for recreational diving in combination with antidepressants.

Author: Michael FM Perez, Janet V Ongkeko-Perez, April R Serrano, Maravic P Andal, Maria CC Aldover Arterial gas embolism is a catastrophic event. Bubbles in the arterial circulation may lodge in the brain and cause infarction in the affected area and/or in a coronary vessel causing acute myocardial ischaemia. There is no well- defined window of time beyond which a response to hyperbaric oxygen is not expected. Major improvement may occur if the patient is treated as soon as possible, but is less likely in divers with severe decompression illness who have delayed intervention. We report on a 51-year- old, male rebreather diver who suffered loss of consciousness and cardiovascular collapse within minutes of a 30-metre deep dive at a remote Micronesian dive site.

Author: Jordan M Warchol, Jeffrey S Cooper, Thomas S Diesing Oxygen toxicity seizures are a well-known complication of hyperbaric oxygen treatment (HBOT). Until now, there have not been any reported cases of an acute ischaemic event (stroke) as the result of a HBOT-associated oxygen toxicity seizure. This document reports an event in which a seizure and stroke occurred together and consider that the stroke may have been caused by seizure-induced demand ischaemia.

Author: Lu Shi, Yan-meng Zhang, Katsuura Tetsuo, Zhong-yuan Shi, Yi-qun Fang, Petar J. Denoble, Yang-yang Li Experience with commercial heliox diving at high altitude is limited. The purpose of this study was to evaluate the effects of acute high-altitude exposure on fitness to dive and the safety of decompression after heliox diving while using U.S. Navy heliox decompression tables with Cross correction.

Authors: W. Oliver Tobin, Sean J. Pittock This article reviews the rapidly evolving spectrum of autoimmune neurologic disorders with a focus on those that involve the central nervous system, providing an understanding of how to approach the diagnostic workup of patients presenting with central nervous system symptoms or signs that could be immune mediated, either paraneoplastic or idiopathic, to guide therapeutic decision making.

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Author: Andreas Fahlman A probabilistic model was used to predict the outcome of decompression sickness (DCS) in pigs (70 and 20 kg), hamsters (100 g), rats (220 g), and mice (20 g) following air-saturated dives. The final model accurately predicted 58 out of 61 dive profiles for pigs, hamsters, rats, and mice. Body mass helped improve the prediction of DCS risk in four mammalian species across a body mass range spanning three orders of magnitude.

Authors: Kate Lambrechts, Costantino Balestra, Michaël Theron, Anne Henckes, Hubert Galinat, Fanny Mignant, Marc Belhomme, Jean-Michel Pontier, François Guerrero The authors of this study aimed to evaluate the effect of bubble formation on vascular function and hemostasis. To achieve this, they used vibration preconditioning to influence bubble levels without altering other parameters associated with the dive. The results suggest that macrovascular impairment, but not microvascular impairment, is at least partly due to bubbles, possibly related to platelet activation and the generation of procoagulant microparticles.

Authors: Laurens E. Howle, Paul W. Weber, Ethan A. Hada, Richard D. Vann, and Petar J. Denoble This study analyzed 3322 cases of air and N2-O2 dives, which included 190 cases of decompression sickness (DCS). These were categorized into serious and mild types using U.S. Navy medical standards. Researchers developed a three-state model to predict the likelihood of mild and serious DCS from dive exposure. This model showed a significant improvement over the two-state model. Applying the Type I/II definition, longer bottom times are permitted for a 2% mild DCS risk, but a significant decrease in allowable bottom time is observed for serious DCS at a 0.1% risk.

Author: Amy E. King, F. Gregory Murphy, Laurens E. Howle This study analyzed research dive trial data from the BIG292 dataset, a primary U.S. Navy model calibration set. Occurrence Density Functions (ODFs) were used to visualize DCS symptom onset rates over time. The study illuminates the complexities of DCS onset times and highlights the need for accurate symptom timing in diving safety protocols.

Authors: B.R. Wienke, T.R. O’Leary Dive computers and diveware are increasingly replacing traditional dive tables due to their crucial role in various diving sectors, including sports, technical, and military diving. . This paper discusses two fundamental biophysical models—oxygen toxicity and risk estimators—that can be integrated into current dive computers and software to assess end-of-dive and on-the-fly (OTF) risks. The study provides comparative results for various diving scenarios implementing these methodologies into existing platforms and aims to enhance safety measures in the diving industry.

Authors: Krzysztof Korzeniewski, Jarosław Krzyzak The authors present this study by stating that since the majority of popular recreational dive sites are located in tropical or subtropical destinations, generally characterized by harsh climates and poor sanitation, recreational divers who are not accustomed to these areas should take preventive measures to reduce health risks. It can be assumed that some of the recommendations in this document will also apply to commercial divers who are not accustomed to working in these areas.

Authors: Lu Shi, Yan-meng Zhang, Katsuura Tetsuo, Zhong-yuan Shi, Yi-qun Fang, Petar J. Denoble, Yang-yang Li The purpose of this study was to evaluate the effects of acute high-altitude exposure on diving fitness and decompression safety after heliox diving using U.S. Navy heliox decompression tables with cross-correction. Decompression safety was assessed by precordial Doppler venous gas embolism (VGE) monitoring during decompression and by post-dive monitoring of divers for symptoms of decompression sickness (DCS).

Author: Claire Walsh This paper describes research on the formation and dynamics of bubbles in the body due to ambient pressure changes, which are linked to decompression sickness (DCS). The author outlines the use of an in vitro matrix model (collagen type I gel) to validate and further develop a 3D computational model of extravascular bubble dynamics and discusses the challenges in validating dive computer algorithms that incorporate mechanistic bubble models, the necessity of direct bubble observation, and the potential of biomimetic in vitro models to address these challenges.

Author: Yun Jung Oh, Ji Yong Jung, Sung Soo Kim, Kyong-Suk Chae, Jiwon Rhu, & Chungsik Lee This study investigates the long-term effects of repetitive breath-hold diving (BHD) on kidney function. Using a cross-sectional propensity score-matched analysis, it specifically examines the prevalence of chronic kidney disease (CKD) among female breath-hold divers compared to non-divers. The results indicate that breath- hold divers have a significantly higher prevalence of CKD, suggesting that repetitive apnea associated with BHD may lead to kidney dysfunction over time.

Authors: Kun Zhang, Mengmeng Wang, Haowen Wang, Yinuo Liu Peter Buzzacott, & Weigang Xu This paper presents the findings of a scientific study investigating the relationship between decompression stress, endothelial injury, and bubble formation in rats to understand the time course of endothelial injury and its correlation with bubble amounts following decompression. The authors detail the methodology, including the simulated air dive, the detection of bubbles, and the measurement of specific biomarkers (MDA, ET-1, ICAM-1). They conclude that endothelial dysfunction correlates with bubble counts and that these biomarkers can serve as sensitive parameters for assessing bubble load and decompression stress

Author: Ran Arieli & Abraham Marmur The authors of this document present a new biophysical model for understanding and predicting the formation and behavior of vascular bubbles during decompression, which is relevant for improving diver decompression procedures. They discuss the mechanisms of bubble formation and expansion, the role of active hydrophobic spots, the factors influencing bubble dynamics, and propose a model that aligns more closely with physiological processes by offering better predictability for decompression illness.

Authors: Surg Capt D K Ghosha, Surg Cdr C Kodangeb, Surg Cdr C S Mohanty, Surg Cdr Rohit Vermad This study focuses on the incidence and management of diving-related injuries such as Decompression Sickness (DCS) and Pulmonary Overinflation Syndrome (POIS) with the purpose of informing on the causes, prevention, and treatment of these conditions, highlighting the low incidence of such injuries among navy divers due to strict adherence to safety procedures and rigorous training.

Authors: S. Lesley Blogg, Andreas Møllerløkken, Mikael Gennser This article discusses the results of a retrospective analysis of post-dive bubbling and DCS incidents from seven studies, using a particular dive profile. It evaluates the safety of this dive profile by comparing observed DCS incidents and bubble measurements with predicted models and historical data.

Authors: Ilaria Marrocco, Fabio Altieri, and Ilaria Peluso This document discusses the challenges and biases associated with the methods used to evaluate oxidative stress in humans. It highlights the lack of consensus on the validation, standardization, and reproducibility of these methods and suggests that using a combination of markers could provide a more comprehensive assessment of oxidative stress. Its authors also emphasize the importance of selecting appropriate markers based on the study's objectives and the clinical relevance to the subjects involved.

Authors: Ed O’Brien , Giorgio Caramanna This study focused on analyzing human factors in scientific diving, particularly during training dives by professional divers. It aims to address individual variability in human factors and their impact on teamwork while also highlighting the dual nature of human involvement in diving as both a strength and a potential source of error. It also shares preliminary findings regarding commonalities and correlations between stressors and human performance among team members.

Authors: Alvhild Alette Bjørkum, Eystein Oveland, Linda Stuhr, Marianne Bjordal Havnes, Frode Berven, Marit Grønning, Arvid Hope. The main objective of the present study was to determine the effects on the brain proteome of fast decompression (1 bar/20 s) compared to controls (1 bar/10 min) after heliox saturation diving, using rats in a model system.

Authors: John Lippmann, David McD Taylor, Christopher Stevenson, Jo Williams, Simon J Mitchell This paper is a survey conducted by the Divers Alert Network Asia-Pacific (DAN AP) on divers with cardiovascular, respiratory conditions, and diabetes to analyze how these divers manage their medical conditions, any modifications they make to their diving practices to mitigate risks, and the outcomes of these practices. It also discusses the methodology of the survey, the results obtained, and the conclusions drawn regarding the safety and risk management of diving with pre-existing health conditions.

Author: Frédéric Beneton, Guillaume Michoud, Mathieu Coulange, Nicolas Laine, Céline Ramdani, Marc Borgnetta, Patricia Breton, Regis Guieu, J. C. Rostain, and Marion Trousselard This study evaluates the benefits of scuba diving on perceived stress and mindful functioning to compare the effects of scuba diving with other recreational sports on stress reduction, mood improvement, and mindfulness. It concludes that recreational diving has greater health benefits in reducing stress and improving well-being compared to other sports.

1 - Physical and physiological aspects of submarine tower escape

Author: Geoff A.M. Loveman This work focused on studying submarine escape and rescue issues, using animal experiments with goats and human trials. Its author developed mathematical models to predict equipment performance and decompression effects and contributed to over sixty reports for the UK Ministry of Defence. His research supports the use of surface oxygen for treating decompression illness and has led to changes in escape policy accepted by the UK Royal Navy and being part of NATO guidelines.

09 - A comparative evaluation of two decompression procedures for technical diving using inflammatory responses: compartmental versus ratio deco.

Authors: Enzo Spisni, Claudio Marabotti, Luigia De Fazio, Maria Chiara Valerii, Elena Cavazza, Stefano Brambilla, Klarida Hoxha, Antonio L’Abbate and Pasquale Longobardi This study compared two decompression methods used by technical divers: the ZH-L16 algorithm with modified gradient factors (CDM) and the ratio decompression strategy (RDS). Fifty-one divers completed a single trimix dive followed by different decompression schedules. Results showed no significant differences in bubbles between the methods, but RDS increased inflammatory markers, indicating a higher risk of vascular damage compared to CDM. No decompression sickness cases were reported.

23 - A technical diving-related burns case: treatment in a remote location

Authors: Fiona C Sharp, Martin DJ Sayer Injuries from a rebreather oxygen explosion and fire affected a diver on vacation in Chuuk, Micronesia. The management of the diver's care in a remote area is described. The causes of the fire and the resulting injuries are discussed. Prevention and preparation for such incidents are highlighted due to the growing popularity of diving and adventure travel to remote locations.

30 - Reliability of Right-to-Left Shunt screening in the prevention of Scuba diving related-decompression sickness.

Author: James Bell, Paul A. Thombs, William J. Davison, Lindell K. Weaver This study investigated how right-to-left shunt (RLS) relates to decompression sickness (DCS) in scuba divers and whether screening for RLS is beneficial for prevention. It compared 634 injured divers with 259 healthy divers, finding higher RLS rates in those with certain types of DCS. Increased RLS size raised DCS risk, but screening is not recommended for routine practice.