Scientific papers 2010
Authors: Tom McLellan, Heather Wright, Shan Rhind,
Bruce Cameron, & David Eaton.
This study compared neuroendocrine and psychomotor
responses in divers (d, n=11) and non-divers (Nd, n=9)
following 30-minute hyperbaric and decompression stress
to 180, 300, and 450 kpa. Venous blood was drawn pre-
dive and at 20 and 60 minutes post-dive and analyzed for
norepinephrine (Ne), epinephrine (e), tryptophan (trp),
cortisol (cor), growth hormone (gH),
adrenocorticotrophic hormone (actH), and prolactin (prl).
Reaction time was assessed using a psychomotor
vigilance task.
Authors: Emmanuel Gempp, Jean-Eric Blatteau
Scuba divers are at risk of decompression sickness due to
the excessive formation of gas bubbles in blood and
tissues following ascent, with potentially subsequent
neurological injuries. Since
nonprovocative dive profiles are no guarantor of
protection against this disease, novel means are required
for its prevention including predive procedures that could
induce more resistance to decompression stress. In this
article, the authors review the recent studies describing
the promising preconditioning methods that might
operate on the attenuation of bubble formation believed
to reduce the occurrence of decompression sickness.
Authors: Marko Ljubkovic, Jasna Marinovic, Ante Obad,
Toni Breskovic, Svein E. Gaustad, and Zeljko Dujic.
SCUBA diving is associated with the generation of gas
emboli due to gas release from the supersaturated tissues
during decompression. Gas emboli arise mostly on the
venous side of the circulation, and they are usually
eliminated as they pass through the lung vessels.
Arterialization of venous gas emboli (VGE) is seldom
reported, and it is potentially related to neurological
damage and the development of decompression sickness.
The goal of the present study was to evaluate the
generation of VGE in a group of divers using a mixture of
compressed oxygen, helium, and nitrogen (trimix) and to
probe for their potential appearance in the arterial
circulation.
Authors: Gerardo Bosco, Zhong-jin Yang, Guglielmo Di
Tano, Enrico M. Camporesi, Fabio Faralli, Fabio Savini,
Angelo Landolfi, Christian Doria, and Giorgio Fanò.
The effect of in-water oxygen prebreathing at different
depths on decompression-induced bubble formation and
platelet activation in scuba divers was evaluated. Six
volunteers participated in four diving protocols, with 2 wk
of recovery between dives.
Authors: Jean-Eric Blatteau, E. Gempp, O. Simon, M.
Coulange, B. Delafosse, V. Souday, G. Cochard, J. Arvieux,
A. Henckes, P. Lafere, P. Germonpre, J.-M. Lapoussiere, M.
Hugon, P. Constantin, A. Barthelemy.
This study aims to determine the potential risk factors
associated with the development of severe diving-related
spinal cord decompression sickness (DCS).
Authors: Michael H. Bennett, MD, Fanzca, Jan P. Lehm,
Simon J. Mitchel, Ph.D, Fanzca, Jason Wasiak.
Recompression is the universally accepted standard for
the treatment of decompression illness (DCI). When
recompression is delayed, a number of strategies have
been suggested to improve the outcome. The authors
examined the effectiveness and safety of both
recompression and adjunctive therapies in DCI treatment.
Authors:
Olivier Castagna, Jeanick Brisswalter, Nicolas Vallee, Jean-
Eric Blatteau
Previous studies have observed that a single bout of
exercise can reduce the formation of circulating bubbles
on decompression, but, according to different authors,
several hours of delay were considered necessary
between the end of exercise and the beginning of the
dive.
The objective of this study was to evaluate the effect of a
single bout of exercise taken immediately before a dive on
bubble formation.
Authors: Pierre Lafere, Ciostantino Balestra, Walker
Hemelryck, Nicole Donda, Ahmed Sakr, Adel
Taher, & Peter Germonpre
Many divers report less fatigue following dives breathing
enriched air nitrox than breathing air. A reduction of post
fatigue with nitrox would suggest a pathological origin,
possibly the presence of asymptomatic nitrogen bubbles
in the body after a dive. The authors studied fatigue in
219 healthy divers performing either air or nitrox 32% O2
dives to 21.2 msw for 43.3 min in tropical waters. The
divers were assessed before the dive and 30 to 60
minutes after surfacing.
Author: Saul Goldman
Thermodynamic expressions are derived for the system
relative Gibbs free energy and the relative Gibbs free
energy per bubble for all possible equilibrium bubble
states that can form in a soft, slightly rigid material, initially
supersaturated with a dissolved inert gas N2 . While the
thermodynamic manipulations are exact, the final
expressions are approximate due to an approximation
made in deriving the expression for the elastic free energy
of a soft material containing more than a single bubble.
Authors: Stephen R. Thom, Ming Yang, Veena M. Bhopale,
Shaohui Huang, and Tatyana N. Milovanova.
Progressive elevations in circulating annexin V-coated
microparticles
(MPs) derived from leukocytes, erythrocytes, platelets, and
endothelial cells are found in mice subjected to increasing
decompression stresses. Individual MPs exhibit surface
markers from multiple cells.
MPs expressing platelet surface markers, in particular,
interact with circulating neutrophils, causing them to
degranulate and leading to further MP production.
Authors: V. Lobo, A. Patil, A. Phatak, N. Chandra
Last research about decompresion illness and the use of
oxygen highlight the role of free radicals.
The body generates free radicals, reactive oxygen species,
and reactive nitrogen species by various endogenous
systems, exposure to different physiochemical conditions,
or pathological states. A balance between free radicals
and antioxidants is necessary for proper physiological
function. Suppose free radicals overwhelm the body’s
ability to regulate them, and a condition known as
oxidative stress ensues. Free radicals thus adversely alter
lipids, proteins, and DNA and trigger many human
diseases.
Authors:
Dionne F. Peacher, Shelly R. H. Pecorella, John J.
Freiberger, Michael J. Natoli, Eric A. Schinazi, P. Owen
Doar, Albert E. Boso, Aaron J. Walker, Matthew Gill,
Dawn Kernagis, Donna Uguccioni, and Richard E. Moon
Based on the fact that previous studies revealed a
progressive increase in ventilation during prolonged
immersed exercise, the authors hypothesized that this
increase occurs because of the development of
metabolic acidosis with a concomitant rise in mean
pulmonary artery pressure and that hyperoxia
attenuates this increase.
Authors: Wayne A. Gerth
The Thalmann Decompression Algorithm (EL-DCA) was
developed using VVal-18 and HVal-21. The original EL-
DCA was extensively modified to develop MK 16 MOD 1
N2 -O2 and He-O2 decompression tables and
Submarine Rescue and Diving Recompression System
Operator/Tender decompression tables. The EL-DCA was
further modified and used with a modified VVal-18
parameter set, designated VVal-18M, to produce an
integrated set of air diving decompression tables for
Revision 6 of the U.S. Navy Diving Manual.
Authors: Le Feng, Christian R. Gutvik, Tor A. Johansen,
Dan Sui
This paper is based on a comprehensive dynamic
mathematical model of vascular bubble formation and
growth during and after decompression from a dive. The
model describes the underlying relationship between
Venous Gas Emboli (VGE) and severe Decompression
Sickness (DCS) risk. Using the Copernicus model, the
diving decompression problem can be formulated as a
nonlinear optimal control problem, where the objective is
to minimize the total ascend time subject to constraints on
the maximum number of bubbles in the pulmonary artery
(also referred to as the decompression stress).
Authors:
Harold Rea, Sue McAuley, Lata Jayaram, Jeffrey Garrett,
Hans Hockey, Louanne Storey, Glenis O’Donnell, Lynne
Haru, Matthew Payton, Kevin O’Donnell
Persistent airway inflammation with mucus retention in
patients with chronic airway disorders such as COPD and
bronchiectasis may lead to frequent exacerbations,
reduced lung function, and poor quality of life. This study
investigates whether long-term humidification therapy
with high-flow, fully humidified air at 37 °C through nasal
cannulae can improve these clinical outcomes in this
group of patients. On the diving side, this study is to be
linked to the quality of breathing gases and conditions
resulting from airway inflammation.
Authors: Mario Alaimo, Giuseppe Aiello, Eduardo Marino,
Leila Zummo, Francesco Cappello
The authors report a case of a 41-year-old expert diver
who, after a series of brath hold dives (60 to 80s/dive at
20 to 24m of depth for 5 consecutive hours), experienced
vertigo, ringing in the left ear, and confusion, followed by
right arm paresthesia trailed by right hemi-paresis after a
few minutes. After <60 minutes from the emergence of
these symptoms, he was admitted to the emergency unit
of our hospital with less severe clinical features, presenting
only confusion and paresthesia of the right hand.
Authors: Venkata M. lla, Nagendra Natarajan, Manu
Kaushik, Rugmini Warrier, Chandra K. Nair
Effort thrombosis, or Paget-Schroetter Syndrome, refers to
axillary-subclavian vein thrombosis associated with
strenuous and repetitive activity of the upper extremities.
Anatomical abnormalities at the thoracic outlet and
repetitive trauma to the endothelium of the subclavian
vein are key factors in its initiation and progression. The
role of hereditary and acquired thrombophilias is unclear.
The pathogenesis of effort thrombosis is thus distinct from
other venous thromboembolic disorders.
Doppler ultrasonography is the preferred initial test, while
contrast venography remains the gold standard for
diagnosis.
Authors: Vanessa Carli Bones Silla, Elaine Cristina de
Oliveira Sans and Carla Forte Maiolino Molento
Animal use in research is an issue of increasing ethical
concern. The objective of this work was to investigate
animal usage in research described in the papers
appearing in 18 journals published in the State of Paraná
in 2006. The fields used in the bibliographic sampling
were agrarian science, biological science, biological and
health science, environmental science, food technology,
and health science. Of the 865 papers analyzed, 41%
involved the use of animals, totaling a total of 3,497,653
animals, of which 216,223 were vertebrates.
Author: Gezina T.M.L. Oei, Nina C. Weber, Markus W.
Hollmann, Benedikt Preckel
This review covers the cellular effects of helium, which
research in cardiac and neuronal tissue has shown that,
besides volatile anesthetics and xenon, the non-anesthetic
noble gas helium also reduces ischemic pre-perfusion
damage. It shows that using this gas may lead to new
clinical strategies for tissue salvage in ischemia-reperfusion
situations, both within and outside the perioperative
setting. This should be considered when designing
decompression tables.
Authors: Chong Si Jack, Liang Weihao, Kim Soo Joang
and Kang Wee Lee
The growing popularity of recreational diving has led to
an increase in diving-related injuries and a higher
demand for specialized medical treatment. In response,
Singapore General Hospital (SGH) has established the
new Hyperbaric and Diving Medicine Centre,
strengthening collaboration with the Singapore Navy
Medical Service (NMS). This partnership, cemented by a
recent Memorandum of Understanding, utilizes NMS's
expertise and SGH's resources to advance research,
training, and the formal recognition of diving and
hyperbaric medicine as a medical subspecialty.
Authors: Rohit Verma
This study discusses a case of musculoskeletal DCI post-
saturation diving, underscoring the unpredictable nature
of DCI and its impact on an individual's fitness for diving.
Authors: Marko Ljubkovic, Zeljko Dujic, Andreas
Mollerlokken, Darija Bakovic, Ante Obad, Toni
Brekovic, and Alf O. Brubakk
The study examined the occurrence and frequency of
venous gas emboli (VGE) after no-stop air dives. Twelve
divers performed six dives each under standard no-
decompression procedures and were monitored for VGE
via ultrasound for 120 minutes post-dive. The results
showed a high production of gas bubbles, primarily
grade 4, with VGE detected in the systemic circulation of
41.7% of divers, particularly when significant bubble
presence was noted in the heart's right valve. Despite the
frequent detection of VGE, no decompression-related
health issues were observed.
Authors: Jan Krog, Else K. Tønnesen, Claus F. Jepsen, Erik
Parner, Kåre Segadal, Arvid Hope, Rune J. Ulvik,
and Marianne E. Hokland
This text presents a scientific study that investigates the
effects of hyperbaric exposure on the human immune
system, specifically focusing on the distribution and activity
of natural killer (NK) cells. The study aims to determine
whether monitoring specific lymphocyte subsets,
including T- and NK-cell subsets, can serve as biomarkers
for hyperbaric stress. The text details the methods used,
including the isolation of peripheral blood mononuclear
cells and the use of 4-color flow cytometry to delineate
lymphocyte subpopulations.
Author: Naoshi Kakitsuba
This study reviews and provides information on thermal
problems and thermal comfort zones in hyperbaric
environments, mainly focusing on the challenges faced by
divers in hyperbaric helium-oxygen atmospheres. The
paper discusses the effects of helium's high thermal
conductivity and increased pressure on heat exchange
between divers and their environment and presents
findings from studies on clothing insulation and
permeability under different pressures. The ultimate goal is
to demonstrate the comfort range of ambient
temperatures at increased barometric pressures.
Author: John W. Castellani, Michael N. Sawka, David W.
DeGroot, Andrew J. Young
The purpose of this document is to inform readers about
the condition known as "thermoregulatory fatigue," which
affects individuals engaged in prolonged, physically
demanding cold-weather activities. The text explains the
physiological responses to cold exposure, such as
shivering and peripheral vasoconstriction, and discusses
how these responses can be impaired by prolonged or
repeated cold exposure and sustained physical exertion.
The text also highlights the potential mechanisms behind
this impairment and the increased risk of hypothermia
associated with thermoregulatory fatigue.
Authors: Mayumi Kajimura, Ryo Fukuda, Ryon M. Bateman,
Takehiro Yamamoto, and Makoto Suematsu
This document reviews and discusses the physiological
roles and interactions of the body's biological gases (O2,
CO, NO, and H2S). It highlights the significance of these
gases as signaling molecules, their interactions with heme-
based proteins, and their effects on mitochondrial
functions such as respiration, biogenesis, and suspended
animation. The review addresses key issues in "gas
biology," including effective tissue concentrations and the
proximity between gas-producing and gas-
receptor/sensor sites.
Authors: Ivan T. Demchenko, Yu Zhilyaev, A. N. Moskvin,
Claude A. Piantadosi, and Barry W. Allen
This text intends to present scientific research findings on
the effects of hyperbaric oxygen (HBO2) exposure at high
pressures on the pulmonary and cardiovascular systems.
The text aims to explain the mechanisms behind acute
pulmonary injury caused by HBO2, mainly focusing on
the role of autonomic nervous system activation and its
impact on pulmonary vascular pressure and heart
function. The research involves experiments on rats to
measure various physiological parameters and to test the
hypothesis that HBO2 exposure leads to significant
sympathetic outflow, resulting in pulmonary and
cardiovascular complications.
Authors: Jon O. Lundberg, Mattias Carlstrom, Filip J.
Larsen, and Eddie Weitzberg
This document informs and highlights the emerging
understanding of the health benefits of inorganic nitrate,
particularly from dietary sources such as vegetables. It
discusses the potential mechanisms through which nitrate
exerts its effects, including the generation of nitric oxide
and other reactive nitrogen oxides, and its impact on
cardiovascular health, exercise performance, and oxidative
stress. The text aims to convey the significance of nitrate in
reducing blood pressure, protecting against
cardiovascular disorders, and potentially contributing to
the beneficial health effects of a vegetable-rich diet.
Authors: Ivan T. Demchenko, S. Yu Zhilyaev, A.N. Moskvin,
Claude A. Piantadosi, and Barry W. Allen
This study aims to elucidate the mechanisms behind acute
pulmonary injury caused by HBO2, particularly focusing
on the role of autonomic nervous system activity and
hemodynamic changes. The research involves
experiments on rats to measure various physiological
parameters and test the hypothesis that extreme HBO2
exposure leads to significant pulmonary vascular pressure
increases and subsequent barotrauma. The findings
suggest that these effects are due to central sympathetic
excitation and catecholamine release, which disrupt the
balance in the autonomic nervous system.
Authors:
Marc M. Berger, Ragnar Huhn, Gezina T. Oei, Andre´
Heinen, Andreas Winzer, Inge Bauer, Benedikt Preckel,
Nina C. Weber, Wolfgang Schlack, Markus W. Hollmann
This scientific study investigates the cardioprotective effects
of hypoxic late preconditioning (LPC) in vivo, specifically in
rat hearts. The study aims to determine whether hypoxic
LPC can reduce ischemia-reperfusion injury and compares
its effectiveness to sevoflurane preconditioning. The text
details the methods used, the results obtained, and the
conclusion that hypoxic LPC significantly reduces infarct
size, with protein kinase C (PKC) playing a key role in this
protective effect.
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Authors: Ran Arieli, Elran Boaron, Yehuda Arieli, Amir
Abramovich, Ksenya Katsenelson
This study investigated the effectiveness of different
hyperbaric oxygen (HBO) pretreatment protocols in
reducing the incidence of decompression sickness (DCS) in
a rat model to determine the optimal oxygen pressure and
exposure duration for pretreatment, as well as how long
the pretreatment remains effective. Its authors also discuss
the results of various pretreatment conditions and their
impact on the occurrence of DCS, highlighting the
potential mechanisms involved, such as the activation of
dormant micronuclei and the rejuvenation of micronuclei
over time.
1 - Decompression Illness Medically Reported by Hyperbaric
Treatment Facilities: Cluster Analysis of 1929 Cases
- Published by Aviation Space and Environmental Medicine
Authors: Tamer Ozyigit, Salih Murat Egi, Petar Denoble,
Costantino Balestra, Salih Aydin, Richard Vann,
and Alessandro Marroni
This study aimed to create an objective DCI classification
using multivariate statistics and evaluate its mapping onto
other classifications. The authors analyzed 1929 DCI cases
reported from 1999 to 2003, confirming internal reliability.
The clusters did not align well with traditional DCI
categories but matched the Perceived Severity Index. All
classification methods predicted relief of symptoms equally
well, showing that cluster analysis is a reliable way to
classify DCI independently of clinical judgment.
13 - Successive deep dives impair endothelial function and enhance
oxidative stress in man
- Published by the Scandinavian Society of Clinical Physiology and Nuclear Medicine
Authors: Ante Obad, Jasna Marinovic, Marko Ljubkovic,
Toni Breskovic, Darko Modun, Mladen Boban,
and Zeljko Dujic
This study aimed to classify DCI using multivariate statistics
and evaluated its relation to treatment outcomes. The
study analyzed 1929 DCI cases from 1999 to 2003,
identifying clusters using statistical methods. The clusters
did not align well with traditional DCI types but matched
the Perceived Severity Index. All classification methods
predicted relief from symptoms equally well, concluding
that cluster analysis offers an objective classification
approach for DCI manifestations.
22 - Hyperbaric pressure effects on voltage-dependent Ca+2
channels: Relevance to HPNS
- Published by the Undersea & Hyperbaric Medical society
Authors: Ben Aviner, Yehudit Gnatek, Gideron
Gradwohl, Yoram Grossman
The review of hyperbaric pressure (HP) effects on
voltage dependent-Ca 2+ channels (VDCCs) aims to
understand their role in high-pressure neurological
syndrome (HPNS). Previous studies rely on indirect
findings, but recent experiments have directly measured
Ca 2+ currents under high pressure conditions. HP's
selective effect on different types of VDCCs determines
their function and influences neuronal network
behavior. Further research is needed to fully understand
HPNS etiology.
25 - The Heat Shock Response: Life on the Verge of Death
- Published by Molecular Cell - Science direct
Authors: Klaus Richter, Martin Haslbeck, and Johannes
Buchner
Organisms survive heat stress by activating a signaling
pathway, triggering the transient expression of heat shock
proteins (Hsps). These proteins, particularly conserved
Hsps, protect proteins from nonspecific aggregates and
assist in acquiring native structures.
35 - Case report: Hyperbaric oxygen in the treatment of puff adder
(Bitis arietans) bite
- Published by The Undersea & Hyperbaric Medical Society (author-released)
Author: Peter p. Rainer, Petr Kaufmann, Freyja M. Smalle-
Juettner, Guenter J. Krejs
A 2.6-year-old Austrian man was bitten by a puff adder, a
dangerous snake found in sub-Saharan Africa. The man
showed signs of local and systemic toxicity, and was
stabilized with antivenom, intravenous fluids,
catecholarnines, and packed platelets. Hyperbaric
oxygenation was used to help him recover. The venom
of Bitis crrietans can cause serious systemic and local
complications, and it is recommended to consider
hyperbaric oxygenation as adjunct treatment in snake
bites.
