scientific-2015

Scientific papers 2015

This report can be considered a Key study regarding gas consumption in an emergency and is taken as a reference in the publications CCO Ltd and Diving & ROV specialists regarding the calculation of the range offered by bailouts. This document can be downloaded from our server by clicking on the picture of the cover, or from the UK HSE server by clicking on the text. UK HSE address: hse.gov.uk/research/rr1073

Authors: Jacek Kot & Zdzislaw Sicko Most operational procedures rely on experimentally found parameters describing a continuous slow decompression rate. In Poland, the system for programming continuous decompression after saturation with compressed air and nitrox has been developed based on the Extended Oxygen Window (EOW) concept. EOW mainly depends on the physiology of the metabolic oxygen window, also called inherent unsaturation or partial pressure vacancy, but also on the metabolism of carbon dioxide, the existence of water vapor, as well as tissue tension.

Ultrasonic techniques allow the visualisation of microbubbles in the heart and blood vessels after diving. Techniques to detect bubbles include Continuous Wave Doppler, Transthoracic Echocardiography, Pulsed Doppler Detection, and Transesophageal Echocardiography. Counting and grading the number of bubbles following diving is a powerful tool to validate current dive tables and algorithms, assess the effect of different preconditioning techniques, and therefore increase diving safety. There are different counting and scoring scales to categorize bubble quantities. Although useful for research applications, bubble counting has limitations in clinical application and, therefore doubtable diagnostic value for the individual DCS risk assessment.

Authors: David J. Doolette, Keith A. Gault, wayne A. Gerth Heliox (He-O2 ) enables diving deeper than limits imposed by breathing N2-O2, but heliox has some costs, and several navies have pursued a trimix (He-N2-O2) diving capability as an alternative to heliox. It is widely believed that trimix bounce dives can be conducted with substantially reduced decompression times than corresponding heliox dives. If this were true, trimix would be an attractive alternative to heliox for U. S. Navy MK 16 MOD 1 underwater breathing apparatus (UBA) diving. However, there is no direct evidence of greater decompression efficiency of trimix than of heliox.

Authors Dror Tal, Hofit Shachar-Bener, Dov Hershkovitz, Yehuda Arieli, & Avi Shupak Mass stranding of cetaceans (whales and dolphins), in close association with the activity of naval sonar systems, has been reported on numerous occasions. Necropsy showed associated bubble lesions similar to those described in human decompression sickness (DCS). The authors examined the hypothesis that exposure to underwater sound may potentiate DCS.

Authors: Arve Lie, Marit Skogstad, Håkon A. Johannessen, Tore Tynes, Ingrid Sivesind Mehlum, Karl-Christian Nordby, Bo Engdahl, Kristian Tambs. This document gives a systematic review of the development of noise-induced hearing loss (NIHL) in working life. It can be used as a complement to the papers more specialized on noise harm linked to diving operations.

Authors: Mircea Degeratu, Simona Rus, Ana Ion. The improvement of the efficiency of diving interventions at depths greater than 15m has brought into focus the problem of increasing underwater working time by using over-oxygenated synthetic breathing mixtures to optimize the relation between working time and duration of decompression. The “nitrox” binary mixture best meets diving requirements at depths within the range of 15 to 50 meters.

Authors: Sigrid Theunissen, Costantino Balestra, Antoine Boutros, David De Bels, François Guerrero, and Peter Germonpré The study aimed to observe the effects of dark chocolate on endothelial function after scuba diving.

18 - Bubbles size on detachment from the luminal aspect of ovine large blood vessels after decompression: The effect of mechanical disturbance

Authors: Ran Arieli, Uri Arieli, & Abraham Marmur. Bubbles nucleate and develop after decompression at active spots on the luminal aspect of ovine large blood vessels. A Series of bubbles were shown to detach from the active spot with a mean diameter of 0.7–1.0 mm in calm conditions. The effect of mechanical disturbance (striking the bowl containing the vessel or tangential flow) was studied on ovine blood vessels stretched on microscope slides and photographed after hyperbaric exposure.

Stephen R. Thom, Michael Bennett, Neil D. Banham, Walter Chin, Denise F. Blake, Anders Rosen, Neal W. Pollock, Dennis Madden, Otto Barak, Alessandro Marroni, Costantino Balestra, Peter Germonpre, Massimo Pieri, Danilo Cialoni, Phi-Nga Jeannie Le, Christopher Logue, David Lambert, Kevin R. Hardy, 1Douglas Sward, Ming Yang, Veena B. Bhopale, and Zeljko Dujic. The authors hypothesized that the number of blood- borne, Annexin V-positive Circulating microparticles (MPs) and neutrophil activation, assessed as surface MPO staining, would differ between self-contained underwater breathing-apparatus divers suffering from DCS vs. asymptomatic divers.

Authors Ming Yang, Otto F. Barak, Zeljko Dujic, Dennis Madden, Veena M. Bhopale, Jasjeet Bhullar, and Stephen R. Thom Predicated on evidence that diving-related microparticle generation is an oxidative stress response. This study investigated the role that oxygen plays in augmenting the production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid.

35 - A red orange extract modulates the vascular response to a recreational dive: a pilot study on the effect of anthocyanins on the physiological consequences of scuba diving.

Authors C. Balestra, F. Cimino, S. Theunissen, T. Snoeck, S. Provyn, R. Canali, A. Bonina, and F. Virgili Nutritional antioxidants have been proposed as an expedient strategy to counter the potentially deleterious effects of scuba diving on endothelial function, flow- mediated dilation (FMD), and heart function. Sixteen volunteers performing a single standard dive (20 min at 33 m) according to US Navy diving procedures were randomly assigned to two groups: one was administered with two doses of 200 mg of an anthocyanin (AC)-rich extract from red oranges, 12 and 4 h before diving.

Authors: Mircea Degeratu, Simona Rus, & Ana Ion Improving the efficiency of interventions made with divers at depths greater than 15m has brought into focus the problem of increasing underwater working time by using over-oxygenated synthetic breathing mixtures in order to optimize the relation between working time and duration of decompression. The "NITROX" binary mixture best meets the requirements of diving at depths within the range of 15 to 50 meters. NITROX is used for depths in the range of 15 to 50 m. When this mixture is used, the decompression time shortens and the respiratory resistance decreases. Therefore, the use of NITROX leads to an improvement in diving efficiency, by increasing underwater working time, and by reducing the decompression time

Authors: Gonglin Hou, Youlan Zhang, Na Zhao, Ruiyong Chen, Weibing Xiao, Hao Yu, Jiachun Wang, and Ti-Fei Yuan. The present study investigated the cognition and performance efficacy of four divers during a simulated 480 meters helium–oxygen saturation diving. The authors analyzed the spatial memory, 2D/3D mental rotation functioning, grip strength, and hand–eye coordination ability in four divers during the 0–480 m compression and decompression processes of the simulated diving.

Author: Ronald W. Day Pulmonary hypertension is a serious disease associated with constriction, cellular hypertrophy and proliferation, inflammation, and in situ thrombosis of the small vessels of the pulmonary circulation. Patients often respond more favorably to long-term treatment if their pulmonary vascular resistance decreases during acute vasodilator testing during heart catheterization. However, the response to short acting agents may not predict the long-term response to medications that act on different pathways of signal transduction. The acute hemodynamic effects of oxygen with nitric oxide and diltiazem were not similar in a previous study of patients with pulmonary hypertension.

Authors: Sebastian Schulz-Stübner, Petra Zimmer, Peter Leonards Hyperbaric oxygen therapy (HBOT) is a non-invasive treatment that involves breathing pure oxygen in a pressurized room or tube. HBOT can be used for chronic wound-healing problems, soft-tissue infections, gas gangrene, and as an emergency treatment for diving decompression sickness or carbon monoxide poisoning. Multiplace hyperbaric therapeutic chambers can accommodate several patients at once, allowing contact among patients who may be infected or colonized.

Authors: Syeda Rubina Gilani, Madiha Batool, Syed Raza Ali Zaidi, Zaid Mahmood, Amanat Ali Bhatti, and Arjumand Iqbal Durrani This study explains the chronic effect of heavy toxic metals on the nervous system. During experimentation, rabbits used as laboratory animals were given test metals in their diet. The concentration of metals given to them in the diet was less than their tolerable dietary intake. Behavioral changes were observed during experimentation. A periodic increase in the metal concentration was seen in the blood sample of rabbits.

Author: Tuomo T. Tompuri Physical activity refers to any bodily movements produced by skeletal muscles that expends energy. Hence the amount and the intensity of physical activity can be assessed by energy expenditure. Metabolic equivalents of task (MET) are multiplies of the resting metabolism reflecting metabolic rate during exercise. The standard MET is defined as 3.5 ml/min/kg. However, the expression of energy expenditure by body weight to normalize the size differences between subjects causes analytical hazards: scaling by body weight does not have a physiological, mathematical, or physical rationale. This review demonstrates that a false methodology may cause paradoxical observations.

Authors: Barbara E. Shykoff A two-part residual oxygen time model predicts the probability of detectible pulmonary oxygen toxicity P(P[O 2 tox]) after dives with oxygen partial pressure (PO2) of approximately 130 kPa and provides a tool to plan dive series with selected risk of P[O2 tox]. Data suggest that pulmonary oxygen injury at this PO2 is additive between dives. Recovery begins after a delay and continues during any following dive.

Authors: Claire Masterson, Gail Otulakowski, and Brian P. Kavanagh Multiple clinical and laboratory studies have been conducted to illustrate the effects of hypercapnia in a range of injuries, and to understand the mechanisms underlying these effects. The aim of this review is to highlight and interpret information obtained from these recent reports and discuss how they may inform the clinical context.

Authors: Martyna Krukowska, Katarzyna Janczuk, Anna Slifirczyk, Marta Kowalenko Pulmonary barotrauma consists in the damage of pulmonary tissues resulting from pressure differences in the body and the surroundings. Barotrauma may occur during diver's ascent with a held breath. Objective: Presentation of symptoms in divers performing dives at shallow depths. A detailed description of pulmonary barotrauma as a direct hazard to life. Rescue procedure in the case of an occurrence of pulmonary barotrauma, methods of prevention.

Authors: Denise F. Blake, Derelle A. Young, and Lawrence H. Brown Hyperbaric nursing has become a specialty requiring high skill and knowledge. Nitrogen narcosis is a perceived risk for all inside hyperbaric chamber nurses. The actual degree of impairment at pressure has not been quantified. Twenty eight subjects participated in the study. Sixteen hyperbaric nurse candidates and five experienced hyperbaric nurses completed Trail Making Test A (TMTA) pre and post compression and at 180 kPa and 300 kPa.

Authors: Guillaume Costalat, Aurélien Pichon, Fabrice Joulia, Frédéric Lemaître Although it has been demonstrated that the exponential decay model fits the heart rate kinetics in short static breath holding, this model might be inaccurate when breath is maintained for several minutes. The aim of this study was to build a new meaningful model to quantify heart rate kinetics during prolonged static breath holding.

Authors: Jacek Kot, Zdzislaw Sicko, Tadeusz Doboszynski Saturation decompression is a physiological process of transition from one steady state, full saturation with inert gas at pressure, to another one: standard conditions at surface. It is a delicate and long lasting process during which single milliliters of inert gas are eliminated every minute, and any disturbance can lead to the creation of gas bubbles leading to decompression sickness (DCS). In Poland, the system for programming of continuous decompression after saturation with compressed air and nitrox has been developed as based on the concept of the Extended Oxygen Window (EOW).

Authors: Simon J Mitchell, & David J Doolette A large right-to-left shunt (usually a persistent foramen ovale) is found in a disproportionate number of DCS cases, suggesting that shunted venous gas emboli (VGE) cause injury to the inner ear. However, this seems an incomplete explanation for the relationship between inner-ear DCS and right-to-left shunt. The brain must concomitantly be exposed to larger numbers of VGE, yet inner ear DCS frequently occurs in the absence of cerebral symptoms. This may be explained by slower inert gas washout in the inner ear than in the brain. Thus, there is a window after surfacing within which VGE arriving in the inner ear (but not the brain) would grow due to inward diffusion of supersaturated inert gas.

Authors: Nico AM Schellart and Jean-Claude Le Péchon The authors aimed to develop a simple but precise method for calculating the instantaneous gas consumption during a dive. With gas thermodynamics and water/gas heat transfer, the instantaneously released gas mass was modeled. In addition, five subjects made an open-water, air, open- circuit scuba dive to 32 metres of seawater. Depth, cylinder pressure, and water temperature were recorded using a dive computer, and gas consumption was calculated and compared using different methods.

Authors: Trientje B Santema, Robert M Stoekenbroek, Koen C van Steekelenburg, Rob A van Hulst, Mark JW Koelemay and Dirk T Ubbink The authors searched multiple electronic databases in March 2015 for cohort studies and randomised clinical trials (RCTs) that reported on the clinical eff ectiveness andtreatment costsof HBOT in the treatmentof acuteor chronic wounds.

Authors: Simin Berenji Ardestani, Peter Buzzacott and Ingrid Eftedal The aim of this study is to elucidate the possible outcomes of the interplay between exogenous and endogenous stress factors on endothelial function and to question potential implications for cardiovascular health in the aging diver.

Authors: Pashtun Shahim, Per Arnell, Andreas Kvarnström, Anders Rosén, Daniel Bremell, Lars Hagberg, Ka Blennow and Henrik Zetterberg Decompressionsickness(DCS) may cause a wide variety of symptoms, including central nervous system (CNS) manifestations. The main objective of this study was to examine whether DCS is associated with neuronal injury, andwhether DCScould result in altered amyloid metabolism.

48 - Comparison of Australian and New Zealand referral rates for hyperbaric oxygen in oro-facial osteoradionecrosis: evidence-based , funding constraint or clinician whim?

Authors: Christopher Sames, Desmond F Gorman, Peter Sandiford and Lifeng Zhou To compare Australian and New Zealand (NZ) rates of referral to hyperbaric units for patients with, or at risk of developing mandibular or maxillary osteoradionecrosis (ORN) due to ahistory of radiotherapy for oropharyngeal cancer. Relevant patient treatment data from all hyperbaric units in Australia and NZ were collated and analysed.

Authors: Kasper Hansen, Esben SS Hansen, Lars P Tolbod, Martin C Kristensen, Steffen Ringgaard, Alf O Brubakk and Michael Pedersen The authors describe the development of a novel preclinical rodent-sized pressure chamber system compatible with computed tomography (CT), positron emission tomography (PET) and magnetic resonance imaging (MRI) that allows continuous, uncompromised, and minimally invasived at a acquisition throughout hyperbaric exposures.The effect of various pressures on the acquired image intensity obtained with different CT, PET and MRI phantoms are characterised.

Authors: Andrew Ng, and Carl Edmonds A 67-year-old female scuba diver developed a typical immersion pulmonary edema (IPE), but investigations strongly indicated Takotsubo cardiomyopathy (TC). The cardiac abnormalities included increased cardiac enzymes, electrocardiographic anomalies, and echocardiographic changes,all reverting to normal within days. This casedemonstratesa similarity and association between IPE and TC, and the importance of prompt cardiac investigations both in the investigation of IPE and in making the diagnosis of Takotsubo cardiomyopathy (TC).

Authors: Lars Eichhorn, & Dieter Leyk The authors reviewed literature from PubMed, a well- known scientific database, on various aspects of diving, including free and scuba diving, medical evaluations, barotrauma, decompression sickness, and diving with medical risks. In conclusion, physicians who certify diving fitness must have a thorough understanding of the physical and physiological impacts of diving, as well as how to evaluate divers medically.

Author: Nick Bushell Currently, no decompression algorithm can guarantee safe decompression in all diving scenarios. Typically, experienced divers or organizations make empirical adjustments to decompression profiles based on the specific dive conditions. Decompression sickness primarily results from bubble formation in the body, suggesting that improved modeling of these processes could enhance the algorithm design. The Study Group aimed to refine the Haldane model by incorporating bubble dynamics, hoping to better understand the physical basis for existing parameter modifications.

Authors: Dariusz Jozwiak, Piotr Siermontowski, Zbigniew DabrowieckiI, Romuald Olszanski Based on data analysis of diving accidents, this study raises the critical question of why recreational diving experiences more accidents than military diving. It evaluates factors such as diving frequency, adaptation to pressure, and overestimation of skills that contribute to higher incident rates in recreational divers compared to military divers.

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01 - Decompression Sickness in Breath-hold diving, and its probable connection to the growth and dissolution of small arterial gas emboli

Authors: Saul Goldman, J.M. Solano-Altamirano This study investigates the behavior of arterial gas embolisms (AGEs) during and after breath-hold diving. It uses a diffusion model to analyze AGE growth and dissolution in different types of breath-hold dives, including single deep competitive dives and repetitive shallower dives, to explain the occurrence of cerebral and inner ear decompression sickness in these diving scenarios and highlight the importance of surface intervals in preventing such conditions in repetitive dives.

Authors: Anahita Fathi-Azarbayjani, Abolghasem Jouyban This paper discusses the significance of surface tension measurements of human biological fluids in understanding and diagnosing various diseases. It outlines how changes in surface tension are linked to pathological states and suggests that these measurements, combined with routine lab tests, could become a valuable non- invasive diagnostic tool. The text also emphasizes the potential of surface tension studies to provide additional information for medical practice and to monitor treatment efficacy.

Author: James E Clark This text informs and educates readers about the challenges and risks associated with exposure to the underwater environment. It particularly focuses on the effects of breathing pressurized gases, such as inert gas narcosis, on divers. It highlights the physiological impacts, symptoms, and potential dangers of nitrogen narcosis and the importance of understanding these effects to promote safe diving practices.

Authors: Bennett MH, Weibel S, Wasiak J, Schnabel A, French C, Kranke P This paper provides an update on a Cochrane Review that assesses the effectiveness and safety of adjunctive hyperbaric oxygen therapy (HBOT) in the treatment of individuals with acute ischemic stroke. It outlines the objectives, search methods, selection criteria, data collection and analysis, and main results of the review, and determines whether HBOT can improve outcomes for stroke patients by reducing brain cell death and swelling. It also summarizes the findings from various randomized controlled trials (RCTs) on this topic.

Authors: A. Sureda, J. M. Batle, J. A. Tur, A. Pons This study evaluated the effects of repetitive hypoxia and reoxygenation episodes during a 5-day apnea diving period on various physiological parameters. Specifically, the study focused on antioxidant defenses, oxidative damage, and plasma xanthine oxidase activity in peripheral blood mononuclear cells (PBMCs) of professional apnea divers. It details the methodology, including the timing of blood sample collection, and summarizes the significant changes observed in glucose levels, triglycerides, enzyme activities, and oxidative markers.

Authors: Peter Germonpré This document provides an overview of diving medicine, emphasizing its interdisciplinary nature and the importance of prevention in maintaining diver health. It also highlights the relevance of research from non-diving medical fields, particularly in relation to Patent Foramen Ovale (PFO), and discusses the complexities and ongoing debates surrounding the treatment and prevention of diving-related and non-diving-related illnesses associated with PFO..

Authors: John W. Castellani, & Michael J. Tipton) The text intends to comprehensively review the physiological responses and external factors that impact cold tolerance and physical performance, define cold tolerance, discuss the effects of short-term and long-term cold exposure, and examine various factors such as habituation, anthropometry, sex, race, and fitness that influence cold tolerance. Additionally, it seeks to explore the impact of cold exposure on aerobic performance, strength, and power and to discuss potential physiological mechanisms and the concept of thermoregulatory fatigue.

Authors: Otto F. Barak, Dennis Madden, Andrew T. Lovering, Kate Lambrechts, Marko Ljubkovic, and Zeljko Dujic This study investigated the occurrence of arterial gas emboli (AGE) in intracranial vessels of SCUBA divers to understand how venous gas emboli (VGE) can become AGE through intrapulmonary arterial-venous anastomoses that open during exercise. The authors detail the methodology, including the use of echocardiography and Doppler techniques, and present the results, which indicate that while some emboli of venous origin can reach the brain, the risk of cerebral embolization is not high in the studied population.

10 - Theoretical tissue compartment inert gas pressures during a deep dive with and without deep decompression stops: a case analysis

Authors: Peter Buzzacott, Virginie Papadopoulou, Adrian Baddeley, Nadan M. Petri, Folke Lind This paper discusses and analyzes the effects and risks associated with deep decompression stops in recreational technical diving. It examines the inert gas pressures in different tissue compartments during a dive with deep stops, using various decompression models, highlighting potential risk factors for decompression sickness, and emphasizing the need for further research to validate the safety of deep decompression stops in diving profiles.

Author: S.F. Storti, E. Formaggio, M. Melucci, F. Faralli, L. Ricciardi, G. Menegaz, L. Pastena This study investigates the effects of oxygen on brain activity in professional divers using new wireless technologies, specifically a Bluetooth system, to measure electroencephalographic (EEG) activity in a hyperbaric chamber to understand how oxygen affects brain activity by analyzing EEG rhythms under different conditions and to provide a reference point for future research on oxygen-sensitive subjects.

Author: F. Jay Haran, Amelia Lovelace This paper evaluates the effects of inspired CO2 and breathing resistance on neurocognitive performance and postural stability during endurance exercise. It outlines the methods used, including the conditions of the dives, the assessments conducted, and the statistical analyses performed. It concludes with the results, which indicate no significant differences were found, and suggests directions for future research.

Authors: Ran Arieli and Abraham Marmur This paper discusses scientific research findings related to the behavior and growth of gas bubbles in ovine large blood vessels following decompression. It describes the experimental setup, observations, and measurements of bubble nucleation and expansion at hydrophobic spots on blood vessels, as well as the factors influencing bubble growth, such as gas tension and flow regime. It also suggests considerations for bubble-based decompression models, emphasizing the importance of accounting for both phases of bubble development.

Authors: Erkan Sukuroglu, Güliz N. Güncü, Kamer Kilinc, and Feriha Caglayan This study investigates the potential use of nitric oxide (NO) levels in biological fluids as biomarkers for evaluating the risk of drug-induced gingival overgrowth to determine whether NO levels in plasma, saliva, and gingival crevicular fluid can serve as indicators for this condition, particularly focusing on patients receiving specific medications. It provides details on the methodology, results, and conclusions of the study, highlighting the potential diagnostic value of salivary nitrite and nitrate levels in cases of phenytoin-induced gingival overgrowth.

16 - Decompression induced bubble dynamics on ex-vivo fat and muscle tissue surfaces with a new experimental set up

Authors: Virginie Papadopoulou, Sotiris Evgenidis, Robert J. Eckersley, Thodoris Mesimeris, Costantino Balestra, Margaritis Kostoglou, Meng-Xing Tang, Thodoris D. Karapantsios Vascular gas bubbles are often seen after scuba dives using ultrasound, but how they form and grow during decompression is unclear. An experiment was set up to capture bubble growth on tissue during decompression. Muscle and fat tissues were tested, and factors like bubble density and growth rates were analyzed. Results showed differences between tissue types and demonstrated how bubbles nucleate and compete for gas.

20 - Cutis marmorata in decompression illness may be cerebrally mediated: a novel hypothesis on the aetiology of cutis marmorata

Author: James Bell, Paul A. Thombs, William J. Davison, Lindell K. Weaver Cutaneous decompression sickness (DCS) is often seen as mild, caused by bubbles in skin blood vessels or tissue saturation during decompression. A 30-year-old female diver had skin DCS three times after low-stress dives. Her skin lesions resembled those in pigs with cerebral air embolism, suggesting a shared cause. This leads to the hypothesis that cutaneous lesions are linked to the brain, indicating that cutaneous DCS may be more severe than previously thought. Further research is needed on the mechanisms behind cutaneous DCS.

44 - Residual oxygen time model for oxygen partial pressure near 130 kPa (1.3 atm)

Author: Barbara shykoff A two-part model predicts pulmonary oxygen toxicity risk after dives with oxygen pressure around 130 kPa. It helps plan dives with controlled risk. Data show injury is accumulative between dives, with recovery starting after delays. The probability formula relates dive duration to toxicity risk. For multiple dives, it calculates an equivalent dive duration. A recovery model was developed based on residual time. The model was validated with 1,352 dives, showing specific standard deviations for resting and exercising divers.

51 - Development of a pulmonary oxygen toxicity risk calculator for repeated dives with PO2 = 1.3 atm.

Author: Barbara shykoff A two-part model predicts the likelihood of pulmonary oxygen toxicity after dives with oxygen pressure around 130 kPa. It shows that lung injury from oxygen accumulates across dives, with recovery starting after a delay. The model includes a logistic equation connecting dive duration to pulmonary oxygen toxicity. For multiple dives, it relates symptoms to equivalent dive duration. A recovery model calculates residual time based on dive factors. The model was validated with 1352 dives, showing acceptable accuracy for specific oxygen pressures and durations.