scientific-2021-part-a

Scientific papers 2021 - Part A

Authors: Kurt Magri, Ingrid Eftedal, Vanessa Petroni Magri, Lyubisa Matity, Charles Paul Azzopardi, Stephen Muscat, and Nikolai Paul Pace. Abstract: Decompression sickness (DCS) develops due to inert gas bubble formation in bodily tissues and the circulation, leading to a wide range of potentially serious clinical manifestations. Its pathophysiology remains incompletely understood. In this study, the authors explore changes in the human leukocyte transcriptome in divers with DCS compared to closely matched unaffected controls after uneventful diving.

Authors: Anna B. Marcinkowska, Natalia D. Mankowska, Jacek Kot, Pawel J. Winklewski. Hyperbaric oxygen therapy (HBOT) is a modality of treatment in which patients inhale 100% oxygen inside a hyperbaric chamber pressurised to greater than 1 atmosphere. The aim of this review is to discuss neuropsychological findings in various neurological disorders treated with HBOT and to open new perspectives for therapeutic improvement.

14 - Routine chest X-rays are inaccurate in detecting relevant intrapulmonary anomalies during medical assessments of fitness to dive.

Authors: Thijs T. Wingelaa, Leonie Bakker, Frank J. Nap, Pieter-Jan A. M. van Ooij, Edwin L. Endert, and Rob A. van Hulst. Intrapulmonary pathology, such as bullae or blebs, can cause pulmonary barotrauma when diving. Many diving courses require chest X-rays (CXR) or high-resolution computed tomography (HRCT) to exclude asymptomatic healthy individuals with these lesions. The ability of routine CXRs and HRCT to assess fitness to dive has never been evaluated.

Authors: Roxane Monnoyer, Kjersti Haugum, Jacky Lautridou, Arnar Flatberg, Astrid Hjelde, and Ingrid Eftedal. During commercial saturation diving, divers live and work under hyperbaric and hyperoxic conditions. The myriads of bacteria that live in and on the human body must adjust to the resultant hyperbaric stress. In this study, the authors examined the shifts in bacterial content in the oral cavity of saturation divers, using a metagenomic approach to determine the diversity in the composition of bacterial phyla and genera in saliva from 23 male divers before, during, and immediately after four weeks of commercial heliox saturation diving to a working depth of circa 200 m

Authors: Richard V. Lundell, Laura Tuominen,Tommi Ojanen, Kai Parkkola, & Anne Räisänen-Sokolowski Technical diving is very popular in Finland throughout the year despite diving conditions being challenging, especially due to arctic water and poor visibility. Coldwater, immersion, submersion, hyperoxia, as well as psychological and physiological stress, all have an effect on the autonomic nervous system (ANS). To evaluate divers’ ANS responses, short-term (5 min) heart rate variability (HRV) during dives in 2–4 degrees C water was measured. HRV resting values were evaluated from separate measurements before and after the dives. Twenty-six experienced closed circuit rebreather (CCR) divers performed an identical 45-meter decompression dive with a non-physical task requiring concentration at the bottom depth.

Authors: Eric Mulder, Arne Sieber, Erika Schagatay Deep freediving exposes humans to hypoxia and dramatic changes in pressure. The effect of depth on gas exchange may enhance the risk of hypoxic blackout (BO) during the last part of the ascent. The purpose of this study was to investigate arterial oxygen saturation (SpO 2 ) and heart rate (HR) in shallow and deep freedives, central variables, which have rarely been studied underwater in deep freediving.

32 - Emergency Medicine Cases in Underwater and Hyperbaric Environments: The Use of in situ Simulation as a Learning Technique.

Authors: Matteo Paganini, Giulia Mormando, Sandro Savino, Giacomo Garetto, Giulia Tiozzo, Enrico M. Camporesi, Fabrizio Fabris, and Gerardo Bosco Hyperbaric chambers and underwater environments are challenging and at risk of serious accidents. Personnel aiming to assist patients and subjects should be appropriately trained, and several courses have been established all over the world. In healthcare, simulation is an effective learning technique. However, there have been few peer-reviewed articles published in the medical literature describing its use in diving and hyperbaric medicine.

Authors: Sanjoy K. Deb, Eimear Dolan, Catherine Hambly, John R. Speakman, Olav Eftedal, Mohammed Gulrez Zariwala, and Ingrid Eftedal Commercial saturation divers are exposed to unique environmental conditions and are required to conduct work activity underwater. Consequently, divers’ physiological status is shown to be perturbed, and therefore, appropriate strategies and guidance are required to manage the stress and adaptive response. This study aimed to evaluate the daily energy expenditure (DEE) of commercial saturation divers during a 21-day diving operation in the North Sea.

Authors: Kurt Magri, Ingrid Eftedal, Vanessa Petroni Magri, Lyubisa Matity, Charles Paul Azzopardi, Stephen Muscat, and Nikolai Paul Pace. In this study, the authors aim to explore changes in the human leukocyte transcriptome in divers with DCS compared to closely matched unaffected controls after uneventful diving. Cases (n = 7) were divers developing the typical cutis marmorata rash after diving with a confirmed clinical diagnosis of DCS. Controls (n = 6) were healthy divers who surfaced from a ≥25 msw dive without decompression violation or evidence of DCS. Blood was sampled at two separate time points—within 8 h of dive completion and 40–44 h later. Transcriptome analysis by RNA-Sequencing followed by bioinformatic analysis was carried out to identify differentially expressed genes and relate their function to biological pathways.

Authors Eric Mulder, Arne Sieber, & Erika Schagatay Deep freediving exposes humans to hypoxia and dramatic changes in pressure. The effect of depth on the gas exchange may enhance the risk of hypoxic blackout (BO) during the last part of the ascent. This study investigated arterial oxygen saturation (SpO2) and heart rate (HR) in shallow and deep freedivers, central variables which have rarely been studied underwater in deep freediving.

Authors: Fabian Möller, Elena Jacobi, Uwe Hoffmann, Thomas Muth, Jochen D. Schipke. Oxygen-enriched air is commonly used in diving and might affect ventilation and heart rate, but little work exists for applied diving settings. This study hypothesized that ventilation is decreased, especially during strenuous underwater fin-swimming when using oxygen-enriched air as breathing gas.

Authors: Wei-Shih Tseng, Nian-Sheng Tzeng, Kung-Hung Lin, Nan-Chieh Huang, Man-Yuan Huang, and Bor-Hwang Kang Divers with a history of decompression sickness may be at high risk for sleep problems. However, limited studies have investigated the relationship between diving exposure and sleep problems of occupational divers. This study investigated the association between diving exposure and sleep quality and quantity among male occupational divers in southern Taiwan.

Author: Alexander Patrician, Željko Dujic, Boris Spajic, Ivan Drviš, and Philip N. Ainslie. Breath-hold diving involves highly integrative physiology and extreme responses to both exercise and asphyxia during progressive elevations in hydrostatic pressure. With astonishing depth records exceeding 100 m, and up to 214 m on a single breath, the human capacity for deep breath-hold diving continues to refute expectations. The physiological challenges and responses occurring during a deep dive highlight the coordinated interplay of oxygen conservation, exercise economy, and hyperbaric management. In this review, the physiology of deep diving is portrayed as it occurs across the phases of a dive.

Authors: Patrice Jissendi-Tchofo, Yassin Jdaoudi, Peter Germonpré, Danilo Cialoni, Andrea Brizzolari, Patrick Musimu, Costantino Balestra. This study hypothesizes that Blood Oxygen Level Dependent signal variations express the functional adaptive diving response under prolonged apnea at rest. That is a preliminary report whose results are promising for large series of investigations.

Authors: Xiao-Chen Bao, Yi-Qun Fang, Tao Yang, Yong-jun Sun, Jun Ma, Ji Xu, Nan Wang, Fang-Fang Wang The authors of this paper tested the changes in pulmonary function of divers after 80m, 100m, and 120m heliox dive. They found that single deep heliox diving can cause temporary expiratory and minor airway dysfunction, which can be recovered 24h after diving. This result increases our knowledge of the impact of the diving environment on the body, and corresponding preventive measures should be taken in this regard.

Authors: Michael R. Kahn, Richard L. Watson, Jay T. Thetford, Joseph Isaac Wong, and Nader Kamangar 21% of patients with severe COVID-19 sustained barotrauma (33% of patients receiving Intermittent mandatory ventilation (IMV), 8% of patients receiving Non-invasive ventilation (NIV). There were no differences between the barotrauma and non-barotrauma groups regarding demographics, illness severity, or medications received, nor tidal volume or average/peak airway pressures in those receiving IMV.

33 - Pneumothorax in critically ill patients with COVID-19 infection: Incidence, clinical characteristics and outcomes in a case control multicenter study

Authors: Amit Chopra, Ali Hani Al-Tarbsheh , Nidhi J. Shah, Hamid Yaqoob, Kurt Hu, Paul J. Feustel g, Ronaldo Ortiz-Pacheco, Kinner M. Patel, Jozef Oweis, Natalya Kozlova, Spyridon Zouridis, Sahar Ahmad, Oleg Epelbaum, Woon H. Chong, John T. Huggins, Biplab K. Saha i, Edward Conuel, Hau Chieng, Jeannette Mullins, Divyansh Bajaj, Boris Shkolnik, Rachel Vancavage, Nagendra Madisi, Marc A. Judson The authors of this study compared mechanically ventilated patients who developed a pneumothorax with those who did not to determine the incidence, clinical features, and outcomes of critically ill patients with COVID- 19 infection who developed pneumothorax.

Authors: Kiyotaka Kohshi, Hideki Tamaki, Frédéric Lemaître, Yoshitaka Morimatsu, Petar J Denoble, Tatsuya Ishitake Clinical characteristics of DCI in Ama divers mainly suggest neurological involvement, especially stroke-like cerebraleventswith sparing of the spinal cord. FemaleAma divers achieving deep depths haver arely experienced apanic-like neurosisfrom anxiety disorders. Neuroradiological studies of Ama divers have shown symptomatic and/or asymptomatic ischaemic lesions situated in the basal ganglia, brainstem, and deepand superfi cial cerebral white matter, suggesting arterial insufficiency.

Authors: David Q. Le, Paul A. Dayton, Frauke Tillmans, John J. Freiberger, Richard E. Moon, Petar Denoble, Virginie Papadopoulou The purpose of this review is to provide a technical overview of the use of ultrasound in decompression research, particularly Doppler ultrasound and brightness (B)-mode ultrasound. Furthermore, the authors discuss the strengths and limitations of these technologies. and how new advancements are improving our ability to understand bubble behavior post-decompression.

Authors: Gabriel-Petric Bala, Ruxandra-Mioara Râjnoveanu, Emanuela Tudorache, Radu Motisan, & Cristian Oancea The goal of this review was to summarize the most important air pollutants and their impact on the main respiratory diseases, including chronic obstructive pulmonary disease and asthma, lung cancer, idiopathic pulmonary fibrosis, respiratory infections, bronchiectasis, and tuberculosis, to reduce both short- and long-term exposure consequences. We considered the most important air pollutants, including sulfur dioxide, nitrogen dioxide, carbon monoxide, volatile organic compounds, ozone, particulate matter, and biomass smoke, and observed their impact on pulmonary pathologies.

Authors: Oskari H Lindfors, Anne K Räisänen-Sokolowski, Jari Suvilehto, Saku T Sinkkonen Middle ear barotrauma (MEBt) is the most common medical complication in diving, posing a serious risk to dive safety. This was a survey study. An anonymous electronic questionnaire was distributed to 7,060 recipients, including professional divers from the Finnish Border Guard, the Finnish Rescue Services, and the Finnish Heritage Agency; and recreational divers registered as members of the Finnish Divers’ Association and reachable by email.

Authors Antonio Barajas-Martínez, Geraldine Tello-Santoyo, Pablo Berumen-Cano, Adriana Robles-Cabrera, Juan Antonio López-Rivera, Ruben Fossion, Juan Claudio Toledo-Roy, Alejandro Frank, Bruno Estañol, and Ana Leonor Rivera Young men have high cardiorespiratory variability, reflecting the balance between robustness and adaptability to environmental and internal changes that characterize good health. However, there are few biomarkers of this variability. Thus, it is important to determine the ranges for healthy men. Moreover, the health condition of women has considerable correlation with their menstrual cycle.

Authors: Suman Sen, Sheuli Sen This review indicates the action of hyperbaric oxygen on biochemical and various physiological changes in cellular level. Narrative review covers the current indications and contraindications of hyperbaric oxygen therapy. The review also focuses on the therapeutic effects of hyperbaric oxygen pretreatment and precondition in different pathological conditions. The complications and side effects of hyperbaric oxygen therapy are discussed.

35 - Therapeutic outcomes evaluation of adjuvant hyperbaric oxygen therapy for non-healing diabetic foot ulcers among sudanese patients

Authors: Ethar Mohamedalfatih Fadol, Hayat Mohamed Suliman, Bashier Osman, Safa A. Abdalla, Wadah J.A. Osman, Elwasila M. Mohamed, Iman Hassan Abdoon. Diabetic foot ulcers (DFUs) are a common complication of diabetes that often leads to amputation and disability. Despite some promising results in using hyperbaric oxygen therapy (HBOT) for DFUs treatment, its efficacy is still debatable. The aim of this study was to evaluate the therapeutic outcomes of adjuvant HBOT in non-healing DFUs treatment.

Authors: Richard Lundell, Vesa Järvinen, Harri Mäkitalo, Kai Parkkola, Tomi Wuorimaa There is limited knowledge of the cumulative effect of repetitive cold-water diving on cardiac function. Single cold dives cause some known cardiological risks, such as malignant arrhythmia, due to a concurrent activation of the sympathetic and parasympathetic autonomic nervous system. A previous study from warmer water dives has shown that successive dives cause a decrease in vagal tone and a less responsive cardiovascular system. The aim of this study was to evaluate changes in cardiac function with 2D echocardiography during 4 days of diving in near-freezing water.

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Authors: Andreas Fichtner, Benedikt Brunner, Thomas Pohl, Thomas Grab, Tobias Fieback, Thea Koch This study evaluated 342 open-circuit air dives using echocardiography and the Eftedal-Brubakk bubble-grade classification system. Post-dive cardiac bubbles were observed in 47% of the dives, which were found to be correlated with dive parameters and age. The authors concluded that simple dives and individual parameters allow for a reasonable estimation of medium to high bubble grades, providing information on decompression stress after ascent. Based on this conclusion, the authors proposed a formula for estimating bubble grades.

Authors: Gianpiero Italiano, Laura Fusini, Valentina Mantegazza, Gloria Tamborini, Manuela Muratori, Sarah Ghulam Ali, Marco Penso, Anna Garlaschè, Paola Gripari and Mauro Pepi Cardiovascular imaging is advancing quickly, with technologies such as three-dimensional echocardiography improving heart structure analysis. New software such as transillumination offers detailed descriptions of valve lesions, crucial for severity grading. In addition, machine learning algorithms now provide fast and accurate chamber quantification, essential for assessing left ventricular function and guiding clinical decisions. This review highlights these innovations in echocardiography, offering deeper insights into heart diseases.

Author: Jan Risberg This systematic review presents the results of a literature search for studies reporting the incidence of DCS, venous gas embolism (VGE), or subjective health reports after multi-day hyperbaric exposure in humans and experimental animals. The results suggest that multi-day hyperbaric exposure is likely to have an acclimatizing effect and protect against DCS. However, the mechanisms causing acclimatization, the extent of protection, and the optimal procedure for acclimatization have not been adequately investigated.

Author: arosław Krzyzak, Krzysztof Korzeniewski New and active divers, whether recreational or professional, are required to have a fitness to dive certificate. This certificate ensures that there are no medical reasons preventing someone from diving. Evaluating health and approving diving under hyperbaric conditions is often the responsibility of a diving instructor, underwater work manager, or physician. Legal standards for these certificates vary between recreational and occupational divers.

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Authors: Danilo Cialoni, Andrea Brizzolari, Michele Samaja, Gerardo Bosco, Matteo Paganini, Massimo Pieri, Valentina Lancellotti, & Alessandro Marroni This study investigates the physiological responses of expert breath-hold divers to repetitive dives. It specifically measures changes in nitrate and nitrite (NOx) concentration, total antioxidant capacity (TAC), and lipid peroxidation (TBARS) in blood plasma before, during, and after the dives. The results indicate significant changes in NOx and TAC levels at the bottom of the dive, which return to normal shortly after surfacing, while TBARS levels remain unchanged throughout the protocol.

06 - External auditory exostoses, repetitive aquatic activity and increasing social complexity in Chalcolithic Cyprus: Specialists of the sea?

Authors: Kirsi O. Lorentz, Bianca Casa This study assesses the prevalence of External Auditory Exostoses (EAEs) in a Chalcolithic skeletal assemblage from Souskiou-Laona, southwestern Cyprus. It aims to understand human-environment interactions, activity patterns, and behavioral differences between sexes based on the presence of EAEs linked to repetitive aquatic activities. The findings suggest that both males and females participated in these activities, with varying prevalence rates, and these differences may reflect increasing specialization and social complexity during the Chalcolithic period.

Authors: Cassondra L. Williams, and Paul J. Ponganis This document provides a comprehensive review of the advancements and current state of research in the field of diving physiology of marine mammals and birds. It outlines the historical context, key developments, and technological advancements that have facilitated field studies, particularly through biologging. It also highlights significant research findings in areas such as heart rate, blood flow, body temperature, and oxygen store management during diving. Additionally, it discusses the challenges and future directions for research in this field.

Authors: Julien D. Periard, Thijs M. H. Eijsvogels, and Hein A. M. Daanen This paper reviews how the human body responds to exercise under heat stress and discusses countermeasures to enhance aerobic performance. The authors describe fundamental concepts and physiological processes related to thermoregulation and fluid balance, methods to determine thermal strain and hydration status, and the impact of heat stress on human performance. They also explore strategies to mitigate the effects of hyperthermia and hypohydration, such as heat acclimation, cooling strategies, and hyperhydration, while summarizing contemporary controversies and suggesting future research directions.

24 - Oxygen-derived free radicals: Production, biological importance, bioimaging, and analytical detection with responsive luminescent nanoprobes

Authors: Jianping Liu, Miaomiao Wu, Run Zhang, Zhi Ping Xu This document aims to comprehensively review oxygen- derived free radicals (ODFRs), their biological significance, and the development of responsive nanoprobes for their detection and bioimaging. It introduces the production and biological importance of ODFRs, summarizes the development of nanoprobes for detecting and imaging superoxide anion and hydroxyl radicals, discusses the specific oxidation mechanisms of these radicals, highlights challenges, and proposes future research directions in this field.

Authors: Yang Saeng Park, John R. Claybaugh, Keizo Shiraki, and Motohiko Mohri This study explains the physiological changes in urine flow and solute excretion that occur during mixed-gas saturation diving under hyperbaric conditions. It describes the mechanisms behind increased diuresis, changes in urine osmolality, and the excretion of various solutes such as urea, potassium (K+), sodium (Na+), calcium (Ca2+), and inorganic phosphate (Pi). It also discusses the roles of hormones like antidiuretic hormone (ADH) and aldosterone in these processes and highlights the need for further research to understand the mechanisms of impaired solute transport in the proximal tubule under these conditions.

Authors: Fang Liang, Nan Kang, Pinpin, Xuehua Liu, Ge Li, Jing Yang This study investigates the effectiveness of hyperbaric oxygen therapy (HBOT) in promoting neural functional recovery after traumatic brain injury (TBI) by encouraging the polarization of microglia (MG) from the pro- inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. The authors compare the expression levels of specific biomarkers associated with M1 and M2 microglia in both control and experimental animal models subjected to HBOT. They conclude that HBOT can suppress pro- inflammatory markers and enhance anti-inflammatory markers, suggesting its potential therapeutic benefits in managing TBI.

Authors: Krzysztof Dziewiatowski, Romuald Olszanski, Piotr Siermontowski This document describes the case of a Polish Navy Dive Medical Officer who experienced decompression illness (DCI) symptoms 20 years ago and was later diagnosed with a right-to-left shunt (RLS) across a patent foramen ovale (PFO), suggesting that this undiagnosed condition may have contributed to the initial DCI incident. The authors argue for the development of standards for initial PFO screening in certain groups of divers to enhance diving safety, recommending the use of contrast- enhanced transcranial Doppler ultrasound for RLS screening and the use of multi-compartment chambers for recompression treatment.

22 - Does the most potent lung surfactant dipalmitoylphosphatidylcholine pose a risk for decompression illness in diving mammals?

Authors: Ran Arieli This document describes findings related to the role of lung surfactants, particularly dipalmitoylphosphatidylcholine (DPPC), in the formation of gas micronuclei that can lead to decompression illness (DCI) in divers. It discusses the mechanisms by which DPPC leaks into the bloodstream and forms active hydrophobic spots (AHS) that contribute to bubble formation during decompression and explores adaptations in deep-diving marine mammals, such as the elephant seal, which have evolved to reduce the risk of DCI by altering the composition of their lung surfactants.

05 - Predicting the effect of decompression sickness on survival following submarine tower escape

Authors: Geoff A.M. Loveman, & Joel J.E. Edney The purpose of the present study was the development of a methodology for translating predicted rates of decompression sickness (DCS), following tower escape from a sunken submarine, into predicted probability of survival, a more useful statistic for making operational decisions. According to the authors’ knowledge, this study represents the first attempt to quantify the effect of different DCS symptoms on the probability of survival in submarine tower escape.

Authors: Oskari H Lindfors, Anne K Räisänen-Sokolowski, Jari Suvilehto, Saku T Sinkkonen Middle ear barotrauma (MEBt) is a common issue in diving, posing a serious risk to safety. This study used an anonymous survey with 7,060 divers, including professionals and recreational divers in Finland. Out of 1,881 responses (27% rate), 81% reported experiencing MEBt. Of those affected, 38% used medications and 1% had surgery. Key risk factors included poor success in Valsalva and Toynbee maneuvers for pressure equalization.

11 - Middle ear barotrauma in diving

20 - The Chemistry of Reactive Oxygen Species (ROS) Revisited: Outlining Their Role in Biological Macromolecules (DNA, Lipids and Proteins) and Induced Pathologies

Author: Celia Andrés Juan, José Manuel Pérez de la Lastra, Francisco J. Plou, and Eduardo Pérez- Lebeña Living species constantly face reactive oxidants from outside sources and those made inside their bodies. There is much research on reactive oxygen species (ROS), their production, effects, and roles in cellular processes. Cells generate ROS normally, but excess levels can cause oxidative stress and disease. Oxidative stress happens when there's a mismatch between radical species production and antioxidant defenses, damaging lipids, proteins, and DNA. This review explores the chemical reactions of ROS and oxidative stress..

21 - Oxygen-derived free radicals: Production, biological importance, bioimaging, and analytical detection with responsive luminescent nanoprobes.

Author: Jianping Liu, Miaomiao Wu, Run Zhang, Zhi Ping Xu Oxygen-derived free radicals (ODFRs) are reactive intermediates formed in living organisms during biological processes. Superoxide anion and hydroxyl radicals are highly reactive and can damage biomolecules. Elevated levels of these radicals are linked to diseases like neurodegenerative disorders and cancers. This review covers the production of ODFRs, their role in diseases, and responsive nanoprobes developed for detecting them. It also discusses challenges and future research directions.

39 - Diving-related disorders in commercial breath-hold divers (Ama) of Japan

Author: Kiyotaka Kohshi, Hideki Tamaki, Frédéric Lemaître, Yoshitaka Morimatsu, Petar J Denoble, Tatsuya Ishitake Decompression illness (DCI) is recognized in compressed- air diving and also reported in breath-hold divers like the Japanese Ama. It often shows neurological symptoms, particularly stroke-like events. Treatment with oxygen is recommended, and prevention strategies include reducing extreme diving.