scientific-2012

Scientific papers 2012

The Thalmann Algorithm parameterized with VVal-18 or VVal-18M underlies U.S. Navy air and nitrox decompression procedures.VVal-18 and VVal-18M air no- stop limits at many depths are longer than the corresponding no-stop limits in the 1957 standard air decompression table that appeared in the U.S. Navy Diving Manual from 1959 until it was replaced in Revision 6 (2008). However, the severity of DCS observed in man- trials of the longer no-stop limits was unacceptable, and consequently, in the Revision 6 air decompression tables, the 1957 air no-stop limits were arbitrarily retained in place of any longer VVal-18M-prescribed limits. This report describes VVal-79, a modification of the VVal- 18M parameter set that enables the use of the Thalmann algorithm to prescribe air diving no-stop limits and decompression obligations that can be used as it is, with no need for arbitrary edits to individual schedules.

Authors: Megan Brenner, Deborah Stein, Peter Hu, MS, Joseph Kufera, MA; Matthew Wooford, Thomas Scalea. The objective of this paper is to investigate the relationship between oxygenation and short-term outcomes in patients with traumatic brain injury (TBI).

Authors: Nicolas Vallee, Cédric Meckler, Jean-Jacques Risso, and Jean-Eric Blatteau. Nitrogen supersaturation and bubble formation can occur in the vascular system after diving, leading to death and nervous disorders from decompression sickness (DCS). Bubbles alter the vascular endothelium, activate platelets, and lead to focal ischemia with neurological damage mediated by the mechanosensitive TREK-1 neuronal potassium ion channel that sets pre-and postsynaptic resting membrane potentials. The authors report a neuroprotective effect associated with TREK-1. Mice were subjected to decompression from a simulated 90 msw dive. Of 143 mice that were wild type (WT) for TREK-1, 51.7% showed no DCS, 27.3% failed a grip test, and 21.0% died. Of 88 TREK-1 knockouts (KO), 26.1% showed no DCS, 42.0% failed a grip test, and 31.8% died. Mice that did not express TREK-1 had lower DCS resistance and were more likely to develop neurological symptoms. We conclude that the TREK-1 potassium channel was neuroprotective for DCS.

Authors: Emmanuel Gempp, Jean Morin, Pierre Louge, and Jean Eric Blatteau. A low-grade process of coagulation activation in association with severe neurological decompression sickness (DCS) in divers has been anecdotally observed. The authors aimed to investigate whether measurement of plasma D-dimers and other hemostatic parameters in injured scuba divers were effective as prognostic biomarkers of neurological DCS, and they compared the diagnostic accuracy of a combination of D-dimers test and initial clinical assessment with either one alone.

Authors: Jean-Eric Blatteau, Sandrine Barre, Aurelie Pascual, Olivier Castagna, Jacques H. Abraini, Jean-Jacques Risso, & Nicolas Vallee. Massive bubble formation after diving can lead to decompression sickness (DCS) that can result in central nervous system disorders or even death. Bubbles alter the vascular endothelium and activate blood cells and inflammatory pathways, leading to a systemic pathophysiological process that promotes ischemic damage. Fluoxetine, a well-known antidepressant, is recognized as having anti-inflammatory properties at the systemic level, as well as in the setting of cerebral ischemia. The authors report a beneficial clinical effect associated with fluoxetine in experimental DCS. Ninety- one mice were subjected to a simulated dive at 90 msw for 45 min before rapid decompression.

Authors: Taiki Miyazawa, Masahiro Horiuchi, Daisuke Ichikawa, Andrew W. Subudhi, Jun Sugawara, & Shigehiko Ogoh. Facial cooling (FC) increases cerebral blood flow (CBF) at rest and during exercise; however, the mechanism of this response remains unclear. The purpose of the present study was to test the author's hypothesis that FC causes facial vasoconstriction that diverts skin blood flow (SkBFface) toward the middle cerebral artery (MCA Vmean) at rest and to a greater extent during exercise.

Authors: R. Arieli & A Marmur It is a long-standing hypothesis that the bubbles which evolve as a result of decompression have their origin in stable gas micronuclei. In a previous study (Arieli and Marmur, 2011), the authors used hydrophilic and monolayer-covered hydrophobic smooth silicon wafers to show that nanobubbles formed on a flat hydrophobic surface may be the gas micronuclei responsible for the bubbles that evolve to cause decompression sickness. On decompression, bubbles appeared only on the hydrophobic wafers. The purpose of the present study was to examine the dynamics of bubble evolution.

Authors: Sema Yilmaz, Kenan Daglioglu, Dincer Yildizdas, Ibrahim Bayram, Derya Gumurdulu, Sait Polat Current treatment modalities and new therapeutic approaches in acute repiratory distress syndrome primarily focused on the resolution of alveolar edema. These treatments include glucocorticoids, surfactants, inhaled nitric oxide, antioxidants and various anti-inflammatory treatments. Unfortunately, to date, none of these pharmacologic treatments has proven to be effective. The authors hypothesized that helium gas might have a beneficial role in the treatment of ARDS.

Authors: Haim Bitterman This small document provides a review of the Hyperbaric oxygen procedures

Authors: Masaki Fujioka, Daisuke Niino, Masahiro Ito, and Yohjiro Matsuoka Patent Foramen ovale is a well know decease that affects many divers and can lead to decompression accidents. This document is the report of an autopsy that revealed a patent foramen ovale of the heart that resulted in the patient dying of paradoxical air embolization of the coronary and cerebral arteries through a patent foramen ovale because of right-to-left shunting.

Authors: Barbara E. Shykoff & Dan E. Warkander Combined effects on respiratory minute ventilation (VE ) and, thus, on end-tidal carbon dioxide partial pressure of breathing resistance and elevated inspired carbon dioxide had not been determined during heavy exercise. In this Institutional Review Board-approved, dry, sea-level study, 12 subjects in each of three phases exercised to exhaustion at 85% peak oxygen uptake while VE and P ET CO2 were measured. Participants inhaled 0%, 1%, 2%, or 3% CO2 in air, or 0% or 2% CO2 in oxygen, with or without breathing resistance, mimicking the U.S. Navy’s MK 16 rebreather underwater breathing apparatus (UBA).

Authors: Paul Schaffer and Reginald F. Baugh Acute otitis externa is a common condition involving inflammation of the ear canal. The acute form is caused primarily by bacterial infection, with Pseudomonas aeruginosa and Staphylococcus aureus the most common pathogens. Acute otitis externa presents with the rapid onset ofear canal inflammation, resulting in otalgia, itching, canal edema, canal erythema, and otorrhea, and often occurs following swimming or minor trauma from inappropriate cleaning. Tenderness with movement of the tragus or pinna is a classic finding.

Authors: Jacek Kot Clear differences between professional and recreational deep diving are disappearing, at least when taking into account the types of breathing mixtures (oxygen, nitrox, heliox, and trimix) and range of dive parameters (depth and time). Training of recreational deep divers is conducted at depths of 120–150 metres and some divers dive to 180–200 metres using the same diving techniques. Extremely deep recreational divers go to depths of more than 200 metres, at which depths the physical and chemical properties of breathing gases create some physiological restrictions already known from professional deep diving.

Authors: Marc Dalecki, Otmar Bock, and Benjamin Schulze Clear differences between professional and recreational deep diving are disappearing, at least when taking into account the types of breathing mixtures (oxygen, nitrox, heliox, and trimix) and range of dive parameters (depth and time). Training of recreational deep divers is conducted at depths of 120–150 metres and some divers dive to 180–200 metres using the same diving techniques. Extremely deep recreational divers go to depths of more than 200 metres, at which depths the physical and chemical properties of breathing gases create some physiological restrictions already known from professional deep diving.

Authors: N.A.M. Schellart , & W. Sterk Decompression tables indicate that a repetitive dive to the same depth as the first dive should be shortened to obtain the same probability of occurrence of decompression sickness (pDCS). Repetition protocols are based on small numbers, a reason for re-examination. Since venous gas embolism (VGE) and pDCS are related, one would expect a higher bubble grade (BG) of VGE after the repetitive dive without reducing bottom time.

Authors: Ingrid Eftedal, Arve Jørgensen, Ragnhild Røsbjørgen, Arnar Flatberg, and Alf O. Brubakk The aim of this study was to analyze genetic reactions that may be involved in acute changes in vascular function in divers. Rats were exposed to 709 kPa of hyperbaric air (149 kPa PO2 ) for 50 minutes, followed by post-dive monitoring of vascular bubble formation and full genome microarray analysis of the aorta from diving rats and unexposed controls.

19 - Lower risk of decompression sickness after recommendation of conservative decompression practices in divers with and without vascular right-to-left shunt

Authors: Christoph Klingmann, Nils Rathmann, Daniel Hausmann, Thomas Bruckner and Rolf Kern Divers with a history of decompression sickness (DCS) who adopted more conservative diving profiles (CDP) showed a significant reduction in the recurrence of DCS, regardless of the presence or size of a right-to-left shunt. This study involved 27 divers who, after experiencing DCS, changed their diving practices upon recommendation. They performed a total of 9,236 dives post- recommendation with only four instances of DCS, compared to 34 instances during 17,851 pre- recommendation dives. This suggests that conservative diving effectively lowers the risk of subsequent DCS.

20 - The Use of Deep Tables in the Treatment of Decompression Illness: The Hyperbaric Technicians and Nurses Association 2011 Workshop

Authors: Michael H Bennett, Simon J Mitchell, Derelle Young and David King In August 2011, the South Pacific Underwater Medicine Society and the Hyperbaric Technicians and Nurses Association held a one-day workshop to discuss the use of deep recompression treatment tables for decompression illness in Australia and New Zealand. The goal was to create consensus statements to guide regional practices, focusing on 405 kPa (30 msw) depth tables with helium- oxygen mixes, covering indications, staffing, and technical requirements. This report summarizes the evidence and consensus statements from the workshop.

Authors: Mayuree Sampanthavivat, Wararat Singkhwa, Thanasawat Chaiyakul, Sangdaw Karoonyawanich and Haruthai Ajpru This study evaluated the effectiveness of hyperbaric oxygen therapy (HBOT) on 60 Thai children with autism aged three to nine years. Participants underwent 20 one- hour sessions of either HBOT at 153 kPa or sham air at 116 kPa. The results indicated significant behavioral improvements in both groups, but no significant differences were found between the HBOT and sham groups. Overall, no definitive clinical benefit from HBOT was observed, although both treatments were safe and well-tolerated.

Authors: Nada Bilopavlovic, Jasna Marinovic, Marko Ljubkovic, Ante Obad , Jaksa Zanchi, Neal W. Pollock, Petar Denoble, Zeljko Dujic The study investigated changes in markers of endothelial and brain damage after repetitive SCUBA diving, while also assessing venous gas bubble production and arterialization. Despite significant bubble production and occasional arterialization, no changes were observed in the levels of endothelin-1 and neuron-specific enolase. However, the levels of the S100 calcium-binding protein B (S100B) were significantly elevated after the 18-meter and control dives, suggesting its release from skeletal muscles rather than indicating brain or endothelial damage.

Authors: Marianne B. Havnes, Catrine Ahlen, Alf O. Brubakk, and Ole-Jan Iversen. This document discusses the findings of a scientific study that investigated the production of autoantibodies against Heat Shock Protein 60 (HSP60) in rats immunized with Pseudomonas aeruginosa and the influence of diving on the levels of these autoantibodies. The study aims to understand the relationship between P. aeruginosa infections, common in saturation divers and cystic fibrosis patients, and the immune response involving HSP60. The results indicate that immunization with P. aeruginosa increases autoantibodies against HSP60, but this increase is not observed in rats that were both immunized and subjected to simulated diving conditions.

Authors: Lisette B. Soegaard, Marie N. Hansen, Cornelis van Elk, Jesper Brahm, and Frank B. Jensen. The study of sea mammals is a path to better understanding physiological phenomena linked to diving. This document explains a scientific investigation into the physiological traits of harbor porpoises that are adaptive for their diving behavior. The study focuses on various aspects such as blood oxygen-transporting properties, buffer characteristics, chloride transport via the erythrocyte anion exchanger (AE1), circulating nitric oxide metabolites, and hemoglobin nitrite reduction.

Authors: Helene N. David, Benoıt Haelewyn, Mickael Degoulet, Denis G. Colomb, , Jean-Jacques Risso, Jacques H. Abraini Argon is known for its high Narcosis properties and is not used in diving breathing mixes for these reasons. However, it can have other applications. This study investigates whether this gas can provide neuroprotection after excitotoxic or ischemic events. The results indicate that while argon has beneficial effects at the cortical level, it may increase subcortical brain damage if administered post-ischemia. The authors suggest that argon should be administered during ischemia, before reperfusion, to maximize its neuroprotective benefits and minimize potential harm.

Authors: Sara R. Zwart, J. Milburn Jessup, Jiuping Ji, Scott M. Smith This study investigated the effects of an oxygen-rich environment on oxidative damage, iron stores, and vitamin status, particularly folate, in humans. It involved participants undergoing a saturation dive in a hyperoxic environment, and it aimed to assess the biochemical markers of iron status, oxidative damage, and vitamin status before, during, and after the dive. The results indicated that increased body iron stores and oxidative stress were associated with decreased folate status and an elevated DNA damage repair response. The study suggests that folate requirements may be higher in such environments.

Authors: Stephen R. Thom, Tatyana N. Milovanova, Marina Bogush, Veena M. Bhopale, Ming Yang, Kim Bushmann, Neal W. Pollock, Marko Ljubkovic, Petar Denoble, and Zeljko Dujic This study evaluated the presence of annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving. It was hypothesized that these changes are related to intravascular bubble formation. The document details the methodology, including the profile of the dives, the timing of blood sample collection, and the techniques used to quantify intravascular bubbles and assess neutrophil activation. It also summarizes the key findings, such as the increase in MPs, neutrophil activation, and the interactions between platelets and neutrophils.

Authors: Ivan. T. Demchenko, Alexander N. Moskvin, Alexander I. Krivchenko, Claude A. Piantadosi, & Barry W. Allen This study evaluated the presence of annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving. It was hypothesized that these changes are related to intravascular bubble formation. The document details the methodology, including the profile of the dives, the timing of blood sample collection, and the techniques used to quantify intravascular bubbles and assess neutrophil activation. It also summarizes the key findings, such as the increase in MPs, neutrophil activation, and the interactions between platelets and neutrophil.

12 - Application of Multifrequency bioelectrical Impedance analysis Method for the Detection of Dehydration status in professional Divers

Authors: Sermin Sengun, Atilla Uslu, Salih Aydin This study investigates the level and source of dehydration in divers who use heliox. Using multifrequency bioelectrical impedance analysis (MF-BIA), it aims to determine whether the dehydration is intracellular, extracellular, or both. The text outlines the study's background, objective, methodology, results, and conclusions.

Authors: Assim A. Alfadda, and Reem M. Sallam This document provides an overview and summary of the roles of reactive oxygen species (ROS) in health and disease. It aims to highlight the biological effects of ROS, their production, and metabolism in cellular organelles like the endoplasmic reticulum and mitochondria, as well as recent research findings that have advanced the understanding of ROS in redox regulation. It also offers a brief perspective on research to enhance the knowledge of ROS actions in various health and disease conditions.

Authors: Yara Bernaldo de Quirós, Oscar González-Diaz, Manuel Arbelo, Eva Sierra, Simona Sacchini, Antonio Fernández As previously mentioned, studies on sea mammals help to understand phenomena linked to diving. This document presents the findings from a survey of gas embolic lesions in stranded cetaceans, particularly in relation to military sonar. It aims to analyze the prevalence, amount, distribution, and composition of gas bubbles in marine mammal tissues, taking into account species-specific variability and the impact of decomposition. It also provides recommendations for necropsy procedures to minimize the masking effects of putrefaction gases and highlights the significance of gas bubble amounts in pathological assessments.

Authors: Manav V Vyas, Amit X Garg, Arthur V Iansavichus, John Costella, Allan Donner, Lars E Laugsand, Imre Janszky, Marko Mrkobrada, Grace Parraga, Daniel G Hackam This study is a systematic review and meta-analysis of observational studies to determine the association between shift work and major vascular events, such as myocardial infarction, ischemic stroke, and coronary events. It outlines the methodology used for data collection and analysis, the results of the studies reviewed, and the implications of these findings for public policy and occupational medicine.

Authors: Mikulas Chavko, Usmah Kawoos, Saleena Adeeb, Jason Lankasky, Charles R. Auker, Richard M. McCarron The authors of this study investigate the protective effects of intermittent hyperbaric oxygen (HBO2) exposure against the central nervous system (CNS) and pulmonary toxicity. The study aims to optimize the duration of HBO2 cycles to enhance protective outcomes. It describes the methods used, including the exposure of rats to different HBO2 cycles and the assessment of lung inflammation and respiratory changes. The results indicate that intermittent HBO2 exposure is more effective in reducing lung inflammation and respiratory changes compared to continuous exposure.

Authors: Christopher J. Morris; Jessica N. Yang; and Frank A. J. L. Scheer This paper intends to convey scientific findings regarding the relationship between the circadian timing system, shift work, and the increased risk of cardiovascular and metabolic diseases. The research explains how the body's internal clock influences cardiovascular risk markers and how misalignment between the circadian rhythm and external factors, such as shift work, can lead to adverse health outcomes.

Authors: Earl S Ford, & Carl J Caspersen This study summarizes research on the relationship between sedentary behavior, specifically screen time and sitting time, and the risk of cardiovascular disease (CVD). Based on prospective studies that primarily used self- reported data, it highlights the association between increased sedentary time and higher risks of both fatal and non-fatal CVD. Additionally, it suggests that future research using more objective measures of sedentary behavior could provide more accurate risk assessments and inform public health guidelines and interventions to reduce sedentary behavior.

Authors: C. Balestra, P. Lafere, P. Germonpre This study investigated the effects of inert gas narcosis (IGN) on divers. The report provides insights into the mechanisms of IGN by measuring critical flicker fusion frequency (CFFF) at various stages of a dive and indicates that IGN may involve gas-protein interactions and that its effects on cerebral function can persist for at least 30 minutes after surfacing. It also highlights the importance of understanding these effects, especially in situations requiring precise judgment or actions.

Authors: Wenbing Xu, Wenwu Liu, Guoyang Huang, ZiJiao Zou, Zhiyu Cai, Weigang Xu This study aims to provide a detailed report on the occurrence, treatment, and outcomes of decompression illness (DCI) cases in a fishery area in northern China. It aims to share findings from a study conducted over a decade, highlighting the effectiveness of recompression treatment schedules and emphasizing the importance of timely intervention.

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