par Balestra, Costantino 
Référence Diving and Hyperbaric Medicine, 44, 3, page (122-123)
Publication Publié, 2014-09
Référence Diving and Hyperbaric Medicine, 44, 3, page (122-123)
Publication Publié, 2014-09
Article révisé par les pairs
| Résumé : | Decompression illness (DCI)/dysbaric disorders represent a complex spectrum of pathophysiological conditions with a wide variety of signs and symptoms related to dissolved gas and its subsequent phase change. Any significant organic or functional decrement in individuals who have recently been exposed to a reduction in environmental pressure (i.e., decompression) must be considered as evidence of DCI until proven otherwise. However, apart from the more obvious acute manifestations, individuals who have experienced repetitive exposures (e.g., commercial or professional divers and active recreational divers) may also develop sub-acute or chronic manifestations sub-clinically - insidious, even if subtle, and almost symptomless. It is, in fact, generally accepted that sub-clinical forms of DCI exist, with little or no reported symptoms, and that these may cause changes in the bones, the central nervous system and the lungs. All this has led us to analysing 'decompression stress', the actual way of understanding decompression. Current research into decompression sickness (DCS) is focused on biological markers that can be detected in the blood. Investigators are exploring the potential association between decompression stress and the presence of membrane microparticles (membrane-bound vesicles shed from a variety of cell types) in the blood. Microparticle levels increase in association with many physiological disease states as well as with the shearing stress caused by bubbles in the blood. The working hypothesis is that certain microparticles (possibly induced by inert gas bubbles) may initiate, be a marker of or contribute to the inflammatory response that leads to DCS. This investigation goes beyond the pure bubble model. While bubbles in the blood certainly play a key role in the development of DCS, their presence or absence does not reliably predict DCS symptom onset. Investigating this process at the molecular level may teach us a great deal more about DCS, providing insights that we hope will improve the effectiveness of both prevention and treatment. Approaches to evaluating decompression stress have considered a wide range of 'markers': different physiological changes after the dive (flow mediated dilatation reduction, blood pressure); personal susceptibility (VO2max, age); environmental factors (altitude, temperature); various physiological states (dehydration, increased vascular resistance as well as bubble counts, predictive decompression models, etc., etc. All this shows how far today's approach to decompression is removed from 'traditional' understanding. It reflects both the need to consider the phenomenon of decompression in a different way than previously and the advances in knowledge over the past 20 years of diving science research. The 14 researchers who have been working for three years under the PHYPODE European Project reached a point where they felt the need to publish a new book in English to allow divers to learn more about the modern approaches to understanding decompression and its problems. Almost every young scientist participating in the PHYPODE project had the responsibility of writing a chapter. This was by no means a simple job considering the different linguistic origins of this group of young researchers, many of whom had their own doctoral theses or research programmes to complete in parallel. Authors also include renowned and established scientists and diving medicine specialists. The intended readership is divers, as well as medically or scientifically educated individuals, interested in increasing their knowledge of the science behind diving and decompression. One may question this project considering the huge amount of information available on the internet on such a topic. Let us illustrate our motivation by means of a story from Japan where one of the major cosmetic companies received a customer complaint because he received an empty soap box. They launched a huge investigation and discovered that the defect arose in the packaging department. The plan was to develop a robust and reliable system ensuring zero defects in the process of product packaging and the company invested heavily in the design and implementation of a solution. A few weeks later, a similar problem occurred in a small soap-manufacturing company in India. This time the approach was very different. The manufacturer bought a big industrial fan and placed it facing the soap box chain. Boxes that were empty simply blew off the chain and the rest moved ahead to the storage house! Our aim was to keep the concepts as clear as possible but maintain the scientific integrity of the subject. References are limited and proposed as further reading. As many of those conceiving some of the new approaches are authors, this is our opportunity to be the "fan that blows empty boxes". As the PHYPODE Project has no means to receive profits from book sales or rights, the book will be published under the name of EUBS/PHYPODE, with EUBS being the beneficiary. The tentative title could be "Diving science for divers - What your diving instructor never told you". The final editor has to be decided during the Excom meeting in Wiesbaden and the book will then be published shortly after. |
