Scientific papers 2024 - Part A
Back to the menu 10 - Does dopamine mediate the effects of exercise on cognition?
Authors: Marc Roig, & Jacopo Cristini Dopamine, a key neurotransmitter, is crucial for managing mood, motivation, learning, and other functions. Changes in dopamine levels are linked to cognitive decline and various mental and neurological disorders, including the cardiorespiratory system. Research, including animal studies, shows that regular cardiovascular exercise, like treadmill running, can boost dopamine levels in the brain, potentially offsetting some of these issues.
01 - Effects of oxygen-prebreathing on tissue nitrogenation in normobaric and hyperbaric conditions
Authors: Edward Tom Ashworth, Ryotaro Ogawa, David Robert Vera, Peter Lindholm Using a radioactive nitrogen isotope, this study found that pre-breathing oxygen at normobaric levels increased nitrogen levels in the blood, liver, and muscle. However, hyperbaric exposure showed no differences in tissue nitrogen levels. Both bone and muscle had higher nitrogen levels after hyperbaric exposure than normobaric exposure. The study concludes that pre-breathing oxygen eliminates nitrogen at normobaric levels, and tissues are slower to adjust their nitrogen levels under hyperbaric conditions.
05 - Stress biomarker changes following a series of repeated static and dynamic apneas in non-divers
Authors: Antonis Elia, Matthew J. Barlow, Matthew J. Lees, Georgios Petri, Michail E. Keramidas This study investigated the physiological effects of repeated maximal static and dynamic apnea on stress- related biomarkers in eleven healthy men. The results showed significant increases in modified albumin and myoglobin levels after the apnea interventions, particularly after dynamic apnea, indicating muscle damage. However, there were no significant changes in neuron- specific enolase or cardiac troponin, suggesting no myocardial or neuronal damage. The study concludes that dynamic apnea causes more muscle damage than static apnea, but neither causes heart or brain damage.
09 - Breathing patterns and associated cardiovascular changes in intermittently breathing animals: (Partially) correcting a semantic quagmire
Authors: Warren Burggren, Andreas Fahlman, William Milsom Many animals exhibit irregular breathing patterns with long pauses between breaths, even when their hearts are beating. This phenomenon is common among all species, from crustaceans to whales. In humans, this irregular breathing pattern is associated with health issues.Diving animals exhibit cardiovascular phenomena that lack standardized terminology, leading to confusion regarding the underlying mechanisms and pathologies. To avoid confusion and emphasize understanding of biological processes rather than terminology, more precise terms are proposed.
11 - Pulsed Hyperoxia Acts on Plasmatic Advanced Glycation End Products and Advanced Oxidation Protein Products and Modulates Mitochondrial Biogenesis in Human Peripheral Blood Mononuclear Cells: A Pilot Study on the “Normobaric Oxygen Paradox”
Authors: Costantino Balestra, Sara Baldelli, Fabio Virgili, Michele Salvagno, Simona Mrakic-Sposta, & Deborah Fratantonio The "normobaric oxygen paradox" (NOP) refers to the perceived lack of oxygen by tissues following a hyperoxic event. The authors investigate whether this phenomenon results in the production of advanced glycation end products (proteins or lipids glycated by exposure to sugars) and advanced oxidation protein products (modified proteins resulting from oxidative stress) as circulating biomarkers of oxidative stress.
12 - Occupational decompression sickness: A case report
Authors: Taylor Diederich, Allyson M. Briggs, Adrienne Malik, Bryan Beaver This article discusses the case of a 32-year-old individual who developed a mottled rash, joint pain, muscle aches, headaches, vision changes, and weakness due to decompression sickness resulting from working in a pressurized chamber at a factory. The individual underwent two sessions in a hyperbaric chamber, which completely resolved the symptoms. During the hospital stay, a patent foramen ovale was discovered. The patient was advised to avoid any further exposure to similar work environments.
13 - Risk Factors for Decompression Sickness
Authors: Elsye Fitriasari, Ni Komang Sri Dewi Untari, Nasywa Annisa Fitra Decompression sickness (DCS) is a serious health problem for divers caused by pressure changes during and after dives. It is important for all medical professionals and divers to understand the risks associated with DCS in order to promote safe diving practices. Symptoms of DCS can be rapid or gradual and may be delayed, making diagnosis difficult, especially if the diver has traveled by air after diving. Factors such as obesity, smoking, alcohol consumption, anxiety, previous injuries, and diving conditions, including cold water, duration, and depth, increase the risk of DCS.
19 - Benefit of breath­holding training on the concept of recreational freediving in healthy adults – a systematic literature review.
Authors: Muhamad Nanang Solikhin, Sumaryanti, Sulistiyono, Fauzi, Bonifacius Arbanto This review covers studies on breath-holding exercises and their health benefits, including their impact on freedive training, lung function through diaphragmatic breathing, and breath-hold performance with mental imagery training. Research also shows improvements in cardiorespiratory function for individuals with bronchial asthma, chronic obstructive pulmonary disease, and cancer, noting better pulse rates, blood pressure, respiratory function, and quality of life.
20 - Review of saturation decompression procedures used in commercial diving
Authors: Jean-Pierre Imbert, Lyubisa Matity, Jean-Yves Massimelli, Philip Bryson This is a review of commercial heliox saturation decompression procedures. The scope does not include compression, storage depth or bell excursion dive procedures. The objectives are to: identify the sources of the procedures; trace their evolution; describe the current practice; and detect relevant trends.
21 - Oxygen imaging of hypoxic pockets in the mouse cerebral cortex
Authors: Felix R. M. Beinlich , Antonios Asiminas, Verena Untiet, Zuzanna Bojarowska, Virginia Plá, Björn Sigurdsson, Vincenzo Timmel, Lukas Gehrig, ichael H. Graber, Hajime Hirase, Maiken Nedergaard Consciousness disappears within seconds after blood flow to the brain stops because the brain cannot store oxygen and requires a continuous supply to function. The researchers developed a new tool to monitor oxygen levels in the brain. Using this tool, they discovered spontaneous low-oxygen areas in the brains of awake mice. This research sheds light on how the brain manages oxygen and could help understand various brain conditions and diseases.
22 - Oxy-Inflammation in Humans during Underwater Activities
Authors: Alessandra Vezzoli, Simona Mrakic-Sposta, Andrea Brizzolari, Costantino Balestra, Enrico Maria Camporesi, and Gerardo Bosco Underwater activities expose divers to conditions that can lead to oxidative stress and inflammation caused by an imbalance between reactive oxygen/nitrogen species and antioxidants. These conditions are influenced by factors such as hypoxic and hyperoxic environments, hyperbaric pressure, cold water, and different breathing gases. Divers experience physiological adaptations known as the "dive response,", which includes cardiovascular stress, increased blood pressure, peripheral vasoconstriction, altered blood gas levels, and the risk of bubble formation during decompression.
37 - In-field use of I-VED electrical impedance sensor for assessing post -dive decompression stress in humans.
Authors: Sotiris P. Evgenidis, Konstantinos Zacharias, Virginie Papadopoulou, Sigrid Theunissen, Costantino Balestra, Thodoris D. Karapantsios Impedance spectroscopy technology (I-VED),was used for the first time in humans to provide qualitative in vivo electrical impedance measurements that may contribute to the assessment of decompression stress. Compared to ultrasound imaging, the proposed method is less expensive, operator-independent, and compatible with continuous monitoring and the use of multiple probes. This study presents preliminary findings. Further calibration and validation are necessary to determine the sensitivity and specificity of I-VED.
38 - Net Heart Rate for Estimating Oxygen Consumption in Active Adults
Authors: José A. Bragada, Pedro M. Magalhães, Eric São- Pedro, Raul F. Bartolomeu, and Jorge E. Morais The study aimed to evaluate the accuracy of predicting oxygen consumption (O2) during aerobic activities using net heart rate (netHR), sex, and BMI in active adults. NetHR is calculated by subtracting the resting heart rate from the average heart rate during the activity. The study involved 156 participants, aged 18 to 81, including 52 women and 104 men, who had their netHR and net oxygen intake (netVO2) measured.
39 - Oxidative Stress Reaction to Hypobaric–Hyperoxic Civilian Flight Conditions
Authors: Nikolaus C. Netzer, Heidelinde Jaekel, Roland Popp, Johanna M. Gostner, Michael Decker, Frederik Eisendle, Rachel Turner, Petra Netzer, Carsten Patzelt, Christian Steurer, Marco Cavalli, Florian Forstner, and Stephan Pramsohler on behalf of the Hypoxiflight Study Group This study aimed to investigate whether flight conditions in a hypobaric chamber, simulating altitudes of 2500 m and 4500 m with varying oxygen levels, could induce oxidative stress in healthy individuals. Twelve vaccinated participants underwent a 3-hour simulation with oxygen levels adjusted between 35% and 100%. Their arterial blood pressure and oxygen saturation were monitored, and blood samples were analyzed for oxidative stress markers at different stages of the experiment.
40 - The Intricate Balance between Life and Death: ROS, Cathepsins, and Their Interplay in Cell Death and Autophagy
Authors: Maya V. Voronina, Anastasia S. Frolova, Ekaterina P. Kolesova, Nikita A. Kuldyushev, Alessandro Parodi, and Andrey A. Zamyatnin Cell survival depends on a balance between the accumulation of damage and repair mechanisms. Oxidants, now recognized as physiological molecules, can damage vital cell components and lead to cell death. Cells counteract this with processes such as autophagy, which recycles damaged parts with the help of lysosomes and enzymes such as cathepsins. These elements help determine whether a cell undergoes apoptosis or autophagy. This review examines the role of ROS and cathepsins in cell death and autophagy, emphasizing their interrelated dynamics.
41 - Progress in the Use of Hydrogels for Antioxidant Delivery in Skin Wounds
Authors: Lidia Maeso, Pablo Edmundo Antezana, Ailen Gala Hvozda Arana, Pablo Andrés Evelson, Gorka Orive, and Martín Federico Desimone Skin is important for protection and healing. Chronic wounds are a worldwide problem caused by oxidative stress that damages cells and delays healing. Proper care and antioxidants can help manage chronic wounds. Natural polymers with antioxidants can create regenerative environments for skin wound healing.
07 - Further perspectives on measuring pulmonary oxygen uptake kinetics
Authors: Harry B. Rossiter, David C. Poole This text acknowledges and corrects a previous mistake in a scholarly work, clarify the correct references, and engage in a professional discussion about the specifics of breath-by-breath gas exchange measurement algorithms. The authors thank Drs. Francescato and Cettolo for their input, correct the misattribution of an algorithm to Grønlund (1984) instead of the intended IND algorithm, and clarify the context of their references. Additionally, they discuss the technical details of the algorithms and seek agreement on a specific point related to the occurrence of expiration between consecutive inspirations.
08 - Role of Oxygen and Its Radicals in Peripheral Nerve Regeneration: From Hypoxia to Physoxia to Hyperoxia
Authors: Dominik André-Lévigne, Rodrigue Pignel, Sylvain Boet, Vincent Jaquet, Daniel F. Kalbermatten, & Srinivas Madduri This study intends to review and discuss the various roles of oxygen in peripheral nerve regeneration, with a particular focus on the potential therapeutic benefits of hyperbaric oxygen therapy. It highlights the influence of different oxygenation states on nerve repair and regeneration, summarizes current knowledge and data on the effectiveness of hyperbaric oxygen therapy for treating nerve injuries, and suggests future research directions in this area.
23 - Baroreflex dynamics during the rest to exercise transient in acute normobaric hypoxia in humans.
Authors: Anna Taboni, Nazzareno Fagoni, Timothée Fontolliet, Giovanni Vinetti, Guido Ferretti This study investigated the physiological responses during a transition from rest to exercise under hypoxic (H) and normoxic (N) conditions. Specifically, the study aimed to test two hypotheses: (i) that the initial decrease in baroreflex sensitivity (BRS) would be slower in hypoxia compared to normoxia, and (ii) that the fast heart rate (HR) and cardiac output (CO) responses would have smaller amplitudes in hypoxia due to lower vagal activity. The text details the study's methods, results, and conclusions, highlighting the differences in physiological responses between the two conditions.
24 - Depth of SCUBA Diving Affects Cardiac Autonomic Nervous System
Authors: Marina Vulic, Branislav Milovanovic, Ante Obad, Duška Glavaš, Igor Glavicic, Damir Zubac, Maja Valic, & Zoran Valic This study investigated the effects of SCUBA diving at different depths (10 m and 20 m) on heart rate variability (HRV) parameters in healthy individuals to determine if cardiac sympathetic activity adapts proportionally to diving depth and if HRV parameters can track changes in cardiac autonomic nervous system (ANS) function during and after diving. The results indicate that SCUBA diving affects the cardiac ANS, with specific HRV parameters showing significant changes during dives and returning to baseline after ascent. The authors suggest that these HRV markers could be used to monitor cardiovascular risks and potential benefits associated with underwater activities.
25 - Chain of events analysis in diving accidents treated by the Royal Netherlands Navy1966–2023
Authors: Benjamin L Turner, Pieter-Jan AM van Ooij, Thijs T Wingelaar, Rob A van Hulst, Edwin L Endert, Paul Clarijs, Rigo Hoencamp This document discusses a study that applied a 'chain of events analysis' (CEA) framework to understand the causes of diving injuries treated by the Diving Medical Centre of the Royal Netherlands Navy to identify the factors leading to these injuries, including predisposing factors, triggers, disabling agents, and disabling conditions, and to evaluate the effectiveness of the CEA framework in analyzing diving injuries.
26 - Decompression illness: a comprehensive overview
Author: Simon J Mitchell This document provides a comprehensive overview of decompression illness, specifically focusing on the pathophysiology, manifestations, prevention, and treatment of decompression sickness (DCS) and arterial gas embolism (AGE). It aims to educate readers about the causes, mechanisms, and potential health impacts of these conditions, as well as to inform them about how to prevent and manage these diving-related disorders.
34 - Prediction of central nervous system oxygen toxicity symptoms using electrodermal activity and machine learning
Authors: Md-Billal Hossain, Kia Golzari, Youngsun Kong, Bruce J. Derrick, Richard E. Moon, Michael J. Natoli, M. Claire Ellis, Christopher Winstead- Derlega, Sara I. Gonzalez, Christopher M. Allen, Mathew S. Makowski, Brian M. Keuski, John J. Freiberger, Hugo F. Posada-Quintero, Ki H. Chon This study aimed to predict central nervous system oxygen toxicity (CNS-OT) in SCUBA divers by analyzing electrodermal activity (EDA) using machine learning techniques. It focused on the dynamics of EDA while subjects are exposed to elevated oxygen partial pressures in a hyperbaric environment. The goal was to develop a predictive model to identify the onset of CNS-OT symptoms early enough to allow for countermeasures, thereby improving diver safety.
35 - Evolutionary genetics of pulmonary anatomical adaptations in deep-diving Cetaceans
Authors: Boxiong Guo, Yixuan Sun, Yuehua Wang, Ya Zhang, Yu Zheng, Shixia Xu, Guang Yang, & Wenhua Ren This study investigates the evolutionary adaptations in the respiratory systems of cetaceans and other marine mammals. It focuses on the genetic basis of these adaptations, particularly in relation to pulmonary fibrosis and diving behavior. It highlights the identification of specific genes that have undergone accelerated evolution and positive selection and how these genetic changes contribute to lung morphology that reduces the risk of decompression sickness (DCS) during diving. The research also aims to provide insights relevant to understanding human diving physiology.
36 - Physiology of deep closed circuit rebreather mixed gas diving: vascular gas emboli and biological changes during a week-long liveaboard safari
Authors: Costantino Balestra, Clément Lévêque, Simona Mrakic-Sposta, Alessandra Vezzoli, Pierre Wauthy, Peter Germonpré, Frauke Tillmans, François Guerrero, & Pierre Lafère. This study discusses the relationship between diving decompression and inflammatory processes. It aims to test the hypothesis that inflammatory processes can generate micronuclei, which may increase the risks associated with diving. It outlines the methodology, including using echocardiography to count venous gas emboli (VGE) and collecting saliva and urine samples to measure various markers of inflammation. The results indicate a correlation between inflammation and the presence of VGE, suggesting that inflammation may play a role in the formation of micronuclei during diving.
43 - Evaluation of North Sea saturation procedures through divers monitoring
Authors: Jean-Pierre Imbert, Axel Barbaud, Sian Stevens, Craig Miller, Hilary Peace, Helene Rossin, Alain Letourneur, Phil Bryson, Bo Damsgaard, Costantino Balestra This study on saturation diving stressors and the effectiveness of different saturation procedures was conducted in the North Sea Danish sector and aimed to document the level of diving stress and compare the Boskalis and NORSOK procedures. The results indicated minimal stress and no significant differences between the two procedures at depths of 40-50 msw. The authors suggest further research for deeper dives where more significant stress is anticipated.
44 - Volatile Organic Compounds in Cellular Headspace after Hyperbaric Oxygen Exposure: An In Vitro Pilot Study
Authors: Feiko J. M. de Jong, Thijs A. Lilien, Dominic W. Fenn, Thijs T. Wingelaar , Pieter-Jan A. M. van Ooij, Anke H. Maitland-van der Zee, Markus W. Hollmann, Rob A. van Hulst, & Paul Brinkman This paper describes a pilot study to identify volatile organic compounds (VOCs) associated with pulmonary oxygen toxicity (POT) using an in vitro model of alveolar basal epithelial cells exposed to hyperbaric and hyperoxic conditions. It also evaluates the feasibility of using this in vitro model for POT biomarker research and details the experimental protocol, the analysis of VOCs using gas chromatography-mass spectrometry, and the findings, which include significant variations in certain VOCs and increased cellular stress markers in the intervention group.
45 - Apnoea as a novel method to improve exercise performance: A current state of the literature.
Authors: Janne Bouten, Louise Declercq, Jan Boone, Franck Brocherie, Jan G. Bourgois This document evaluates the potential of apnoea as a training method to enhance aerobic performance and discusses the effectiveness of different apnoea protocols. It concludes that while apnoea-induced spleen contraction can improve oxygen uptake kinetics, it does not immediately enhance aerobic performance. Additionally, only long and intense apnoea protocols in experienced individuals show significant increases in erythropoietin and reticulocytes. The authors suggest that variations of apnoea training may have potential for improving exercise performance.
46 - Post-exercise hot or cold water immersion does not alter perception of effort or neuroendocrine responses during subsequent moderate-intensity exercise
Authors: Campbell Menzies, Neil D. Clarke, Christopher J. A. Pugh, Charles J. Steward, C. Douglas Thake, Tom Cullen This document presents the findings of a scientific study that investigated the effects of post-exercise hot water immersion (HWI) and cold water immersion (CWI) on recovery and subsequent performance in endurance- trained runners. It determines whether these recovery strategies influence physiological and psychological responses, as well as performance in a second training session performed later the same day. The results suggest that while HWI and CWI affect certain physiological markers, they do not negatively impact perceived effort, recovery, or performance in subsequent moderate- intensity training sessions.
27 - Fatigue in construction workers: A systematic review of causes, evaluation methods, and interventions
Authors: Haiyi Zong, Wen Yi, Maxwell Fordjour Antwi- Afari, Yantao Yu This paper presents a systematic review of research on fatigue among construction workers. It aims to elucidate the current state of research, identify issues, and propose potential improvements in understanding and managing fatigue in the construction industry, outlining an approach that combines systematic review and bibliometric analysis to examine research themes, methods, and findings related to worker fatigue. It also highlights the causes of fatigue, evaluation methods, interventions, research challenges, and future research directions, with the ultimate goal of enhancing occupational health and safety in the construction industry.
28 - Diving Medicine: An Exciting Journey Through Time and Future Prospects
Authors: Dimitra Ioanna Lampropoulou, Dimitrios Papageorgiou, Evangelia Pliakou This document is an analysis of diving medicine's historical development and significance, mainly focusing on the advancements in hyperbaric medicine and its applications. It highlights the challenges faced by divers, the emergence of decompression illness, and the contributions of hyperbaric treatment to modern medical science. In addition, it emphasizes ongoing research and interest in using hyperbaric oxygen for various medical conditions.
29 - The interaction of breath holding and muscle mechanoreflex on cardiovascular responses in breath-hold divers and non-breath- hold divers
Authors: Nakamura Nobuhiro, Peng Heng, Hayashi Naoyuki This study investigates the interaction between breath holding (apnea) and muscle mechanoreflex on cardiovascular responses in breath-hold divers (BHDs) compared to non-breath-hold divers (non-BHDs) to understand how these two opposing responses—bradycardia from apnea and tachycardia from exercise—affect heart rate and cardiac output during diving. The results indicate that BHDs prioritize bradycardia over tachycardia, suggesting that diving training alters cardiovascular control mechanisms.
32 - North Sea Divers Age Survey
Authors: Steve Sheppard This Helix presentation provides information about the age profiles for various positions employed by North Sea Contractors, acknowledging the potential for data duplication due to personnel being employed by multiple contractors. However, its author estimated that this duplication was less than 4% of the total dataset.
33 - Physiology of deep closed circuit rebreather mixed gas diving: vascular gas emboli and biological changes during a week-long liveaboard safari
Authors: Costantino Balestra, Clément Lévêque, Simona Mrakic-Sposta, Alessandra Vezzoli, Pierre Wauthy, Peter Germonpré, Frauke Tillmans, François Guerrero, and Pierre Lafère The Paper presents a study on diving decompression theory, specifically examining the role of inflammatory processes in the formation of micronuclei and their potential risks by testing divers to observe changes in inflammatory markers and venous gas emboli (VGE) post- dive. It details the methods, results, and discussion of the findings, highlighting the relationship between inflammation and VGE and suggesting that increased inflammation may lead to the formation of new micronuclei.
49 - Effects of Resistance Exercise with and without Blood Flow Restriction on Acute Hemodynamic Responses: A Systematic Review and Meta-Analysis
Authors: Anderson Geremias Macedo, Danilo Alexandre Massini, Tiago André Freire Almeida, Luciana Maria dos Reis, Giovane Galdino, Adriana Teresa Silva Santos, Osvaldo Tadeu da Silva Júnior, Rubens Venditti Júnior, and Dalton Muller Pessôa Filho This document presents a systematic review and meta- analysis that examines the acute and post-exercise hemodynamic responses to low-load intensity resistance exercise with blood flow restriction (BFR) compared to high-load intensity resistance exercise (HI) to determine whether the cardiovascular responses, specifically heart rate, blood systolic and diastolic pressure, and rate pressure product, immediately after and up to 60 minutes post-exercise, are consistent between the two exercise protocols in healthy individuals.
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06 - NDTT – Probability of decompression sickness
Author: Jan Risberg The editors of the Norwegian Diving and Treatment Tables (NDTT) inform readers about safety performance since the fourth edition. This document explains the difference between the observed and predicted DCS rates. It has been created by the first author of the editorial team and is meant as supplementary information, not part of the tables. It does not meet scientific manuscript quality criteria.
17 - Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species..
Author: Michele Salvagno, Elda Diletta Sterchele, Mario Zaccarelli, Simona Mrakic-Sposta, Ian James Welsby, Costantino Balestra, and Fabio Silvio Taccone The brain is highly vulnerable to oxidative stress due to its characteristics, which can harm its vascular tone in critically ill patients or those with acute brain injuries. High metabolism and poor mitochondrial function cause significant reactive oxygen species (ROS) production. Non- replicating neurons and low repair abilities increase vulnerability. ROS affects blood vessel function, and different species have varying effects. Antioxidants like superoxide dismutase, vitamin C, and vitamin E show the potential to protect against oxidative stress.
18 - Safety of Hyperbaric Medicine in Clinical Scenarios
Author: Vishal Mago Hyperbaric therapy is generally considered a safe therapy for the treatment of wounds, mucormycosis, and orthopedic injuries. It is fraught with complications such as barotrauma, pulmonary toxicity, fire hazards, and claustrophobia. This article discusses the safety protocols and preventive aspects on usefulness of this new emerging therapy.
31 - Barodontalgia and its implications for Navy divers and dentists: A narrative review.
Author: Javier García-Torres, Juan J. Segura-Egea This study reviews barodontalgia and its impact on divers . A search for relevant articles was conducted in several databases. Barodontalgia is rare but more common in military divers, especially affecting upper teeth. It is linked to how teeth respond to pressure changes. Diagnosis is difficult because the conditions cannot be easily recreated in dental offices. Military dentists need to be aware of barodontalgia to prevent it in divers.
02 - Compression and excursion parameters for saturation dives 0 - 250 msw
Author: Jan Risberg, & Kare Segadal A study by the Petroleum Safety Authority Norway (PSA) compared commercial heliox saturation compression and excursion procedures for diving up to 250 msw. The study found significant variation in compression rates and excursion ranges, but no outcome data suggested superiority. The study also found no evidence of excessive high pressure nervous syndrome (HPNS) during compression, and no data suggesting unsafe excursion ranges. There is a lack of data supporting NORSOK U- 100:2015 restrictions on ascending excursions and narrow excursion ranges for shallow saturation diving.
03 - Combined effects of mild hypothermia and nitrous-oxide- induced narcosis on manual and cognitive performance
Author: Maaike I. Moes, Antonis Elia, Mikael Gennser, and Michail E. Keramidas Divers are at risk of cognitive deterioration due to low ambient temperatures and high-pressure inert gases. A study found that mild hypothermia and nitrous oxide narcosis during prolonged cold exposure aggravate basic and higher-order cognitive abilities. The study found that cooling impaired short-term memory and learning, but not finger dexterity or attention.
04 - Effects of Oxygen Prebreathing on Bubble Formation, Flow- Mediated Dilatation, and Psychomotor Performance during Trimix Dives
Author: Ivana Segrt Ribicic, Maja Valic, Linda Lusic Kalcina, Josko Bozic, Ante Obad, Duska Glavas, Igor Glavicic, and Zoran Valic The study investigated the impact of air and oxygen pre- breathing on bubble formation, flow-mediated dilatation, and psychomotor performance after scuba dives. Twelve divers performed two dives using a gas mixture of oxygen, nitrogen, and helium. The oxygen prebreathing protocol significantly reduced bubble grade and post-dive psychomotor speed, suggesting a beneficial role for endothelial function. The total test solving times after the dives were shorter in the oxygen prebreathing protocol.
14 - The first deep rebreather dive using hydrogen: case report
Author: Richard J Harris, Craig J Challen, Simon J Mitchell Bounce diving can cause high-pressure neurological syndrome (HPNS) if rapid descents to deep depths are made. Nitrogen in the respired gas can help reduce HPNS, but it may exceed guidelines. In 2020, a team explored Pearse Resurgence cave, New Zealand, using a breathing trimix. Hydrogen, a light, slightly narcotic gas, was suggested as a solution, but concerns include potential ignition and explosion. Hydrogen could help improve HPNS symptoms while maintaining gas density.
15 - Acute and chronic central nervous system oxidative stress / toxicity during hyperbaric oxygen treatment of subacute and chronic neurological conditions
Author: Paul G. Harch, and Stacey Rhodes This study identifies acute and chronic CNS oxygen toxicity under 2.0 atmospheres absolute pressure of oxygen. It found that hyperbaric oxygen therapy-generated cases of CNS oxygen toxicity in chronic neurological conditions were identified at <2.0 ATA. Chronic CNS oxygen toxicity is unpredictable and occurs at an average threshold of 103-116 AHs with wide variability.
16 - Hyperbaric oxygen therapy for thalamic pain syndrome: case report
Authors: John Benjamin Slade, Nathan Kwan, Peter Lennox and Russell Gray Thalamic pain syndrome is a distressing type of central post-stroke pain (CPSP) that occurs in up to 10% of cases following a cerebrovascular accident. It is often chronic or life-long and is difficult to treat. The thalamus may play a significant role in some patients with central pain. Long- term post-stroke pain disorders can reduce quality of life, affect mood, sleep, and social functioning, and can lead to suicide. Hyperbaric oxygen therapy, which has been shown to be beneficial in brain-related hemorrhages, stroke, and neurodegenerative diseases, may be a treatment option for thalamic pain syndrome.
30 - Real-time imaging of decompression gas bubble growth in the spinal cord of live rats.
Author: Roman Alvarado, Ulrich M. Scheven, Jens- Christian Meiners The study used an MRI-compatible pressure chamber system to observe the growth and resolution of decompression gas bubbles in the spinal cord of live rats in real time. The system pressurizes and depressurizes rodents, monitoring their respiratory rate, heart rate, and body temperature while providing gaseous anesthesia.
42 - Breath-Hold Diving Injuries - A Primer for Medical Providers
Authors: Elaine Yu, DO, Juan M. Valdivia-Valdivia, Fernando Silva, and Peter Lindholm Breath-hold divers face unique injuries compared to surface swimmers and compressed air divers. This guide provides medical providers with information on managing breath-hold diving injuries in the field. Hypoxia, negative pressure barotrauma, positive pressure barotrauma, inert gas loading, asymptomatic cardiac arrhythmias, and glossopharyngeal breathing methods can all contribute to these risks. The guide also includes equipment for medical support at organized breath-hold diving events to facilitate diagnosis and treatment outside of the hospital setting.
Authors: Gerard Laden, Bruce Mathew Nitrogen narcosis, a substance that impairs prefrontal cortex function, can lead to cognitive impairment and fatal accidents. Studies have shown that divers may experience negative effects of a narcotic agent, even at shallow depths. In 1872, English law made it illegal to be "drunk" while driving, but it took 100 years for driving above a legal limit in the UK. The question remains whether modern society will tolerate another century before legally defining safe parameters for nitrogen narcosis.
47 - Drinker driver flyer diver
48 - Narcotic Nitrogen Effects Persist after a Simulated Deep Dive
Author: Sven Dreyer, Johannes Schneppendahl, Martin Hoffmanns, Thomas Muth, and Jochen D. Schipke This study tested the hypothesis that breathing oxygen before surfacing can reduce postdive IGN. A group of 58 experienced divers underwent a 5 minute dive at 50 m in a hyperbaric chamber. The participants performed the Sharpened Romberg test and a modified tweezers test. Results showed that the air group had a greater impairment in the vestibular system, while the O2 group had a higher number of beads picked due to the learning effect.
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