Introduction: The popularity of SCUBA diving is steadily increasing together with the number of dives and correlateci decompression sickness (DCS) cases per year. DAN Europe continues to collect in-field data from divers building the largest database of dive parameters, post-dive gas bubble load, persona I risk factors and occurrence of DCS. An initially developed database (DAN DB) including specific questionnaires for data collection allowed in 2017 the statistica I analysis of 39,099 electronically record ed open circuit dives made by 2,629 European divers (2,189 mal es 83.3%, 440 females 16. 7%) over 5 years [1]. This report includes the update of the database. Methods: An originally developed database (DAN DB) now including specific questionnaires for data collection provided 137,421 electronically recorded recreational dives made by 5,907 divers (males 86.7%, females 13.2%) over 9 years and between 2.2 and 192 msw depth, using both open circuit scuba and rebreathers, up to an altitude of 2,400 m above sea level. There were 628 DCS cases reported, sometimes as a single event fora diver, and sometimes repeatedly occurring in the same diver (up to seven incidents per single diver). Results: Dives which finished with DCS were different than those without DCS, by several factors including number of dives in series, surface interval, maximum depth and run-time, as well as DSSG factor (DAN Surface Supersaturation Gradient), but most of them could be described as acceptably safe, according to the current decompression algorithms. Preliminary analysis of persona! factors confirms that age and BMI play a role in DCS. lnterestingly, in our materiai, DCS was observed more in females (1.25%) than in males (0.375%). Multifactorial analysis will help in identifying additional risks relateci with diving conditions, underwater stress, and well-being condition before diving. Conclusion: The DAN DB analysis shows that most dives were made in a "safe zone," but our data also clearly show a "gray area" and fai Iure in the current algorithms ability to "mathematically" predict DCS. Other risk factors, both individuai and environment relateci also seem to influence the possibility to develop DCS, irrespective of bubble formation, showing the importance of non-strictly decompression relateci risk factors, but rather individuai susceptibility and/or environment relateci variables, influencing the dive's outcome or possibly enhancing the effects of bubbles. The Data coming for our DB Analysis are now being used to develop a novel experimental model aimed at a statistica!, epidemiologica I and probabilistic approach to individualized safe decompression.

Background: The present study was designed to observe if different decompression profiles, calculated as a function of tissue supersaturation during ascent, would result in significantly different outcomes, measured through different physiological stress indicators, even in the absence of symptoms of decompression sickness. Aim: The aim of this study was to evaluate if simulated decompression profiles would affect the immune system, oxidative stress indicators, and heart rate variability. Methods: A total of 23 volunteers participated in two different experimental protocols in a dry hyperbaric chamber. These simulated dives comprised two different compression–decompression arrangements with the same maximum pressure and duration but different decompression profiles. Results: The shallow decompression profile with shorter deeper stops and longer shallow stops presented an increase in the standard deviation of the normal-to-normal R-R interval (a wide indicator of overall variability); the deep decompression profile with longer deeper stops and shorter shallow stops did not exhibit such increase. The shallow decompression profile resulted in an increase in neutrophil count and its microparticles (MPs), but no changes were observed for platelet count and its MPs, as well as for endothelial-derived MPs. In contrast, the deep decompression profile resulted in no changes in neutrophil count and its MPs, but a decrease in platelet count along with an increase in MPs from both platelets and endothelial cells. The observed difference might be related to different levels of decompression-related activation of immune system responses and oxidative processes triggered by different levels of inert gas supersaturation upon surfacing. Conclusion: From previous results and literature data, we present a tentative schematic of how the velocity of ascent would trigger (or not) pro-inflammatory and immune system responses that could ultimately lead to the development of decompression sickness. Relevance for patients: Increasing safety in exposure to hyperbaric environments and subsequent decompression by evaluating individual physiological responses to the proces.

Introduction: Preterm birth may significantly impair the functional and anatomical development of the respiratory system and could be a background for various life-long medical sequelae.

Hypoxia, centralization of blood in pulmonary vessels, and increased cardiac output during physical exertion are the pathogenetic pathways of acute pulmonary edema observed during exposure to extraordinary environments.

The brain’s unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms.