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Isolated, confined, and extreme environments hold the opportunity to collect unique biomedical data. These often-remote places present specific medical challenges for deployed expeditioners. Here we report a case of acute severe high altitude pulmonary oedema (HAPE) and its management at a remote research station in Antarctica. At the beginning of the 2023 summer campaign at Concordia Station (3200 m AMSL), a technician presented with shortness of breath and compromised circulation three days after arrival on site. Immediate diagnostics and medical treatments with high-flow oxygen and the use of a mobile hyperbaric chamber after initial resuscitation were administered. Within a time window of 24 h, evacuation to sea level was organised via aircraft (flight duration 4 h, non-pressurised cabin) inside the mobile hyperbaric chamber. The patient was discharged from medical treatment 48 h later in Christchurch (NZ). We conclude that despite rigorous pre-deployment screening, even experienced expeditioners can develop critical medical conditions that require prompt reaction and rescue. Structured assessment tools can aid in their recognition and management.

Taking S32101 duplex stainless steel as the research object, underwater laser wire filling welding technology was used for U-groove filling welding. The influence of different shielding gas compositions on the ferrite content, microstructure, mechanical properties and pitting corrosion resistance was studied by simulating a water depth of 15 m in the hyperbaric chamber. The results show that, under the same process parameters, the size and proportion of austenite in the weld when using pure nitrogen as the shielding gas are larger than those protected by other shielding gases. In a mixed shielding gas, the increase in nitrogen content has little effect on the strength and toughness of the weld. Regardless of the shielding gas used, the base metal was the weakest part of the weld. At the same time, intermetallic inclusions have an adverse effect on the impact toughness of the weld. The pitting corrosion resistance of the welds depends on the Cr2N content in the heat-affected zone. The precipitation and enrichment of Cr2N causes local chromium deficiency, which is the main factor for the weak pitting corrosion ability of the heat-affected zone. Pure nitrogen protection has a better corrosion resistance than other gas protection.

Plateau hypoxia represents a type of hypobaric hypoxia caused by reduced atmospheric pressure at high altitudes. Pressurization therapy is one of the most effective methods for alleviating acute high-altitude sickness. This study focuses on the development of an advanced control system for a vehicle-mounted mild hyperbaric chamber (MHBC) designed for the prevention and treatment of plateau hypoxia. Conventional control methods struggle to cope with the high complexity and inherent uncertainties associated with MHBC control tasks, thereby motivating the exploration of sequential decision-making approaches such as reinforcement learning. Nevertheless, the application of sequential decision-making in MHBC control encounters several challenges, including data inefficiency and non-stationary dynamics. The system’s low tolerance for trial-and-error may lead to component damage or unsafe operating conditions, and anomalies such as valve failure can emerge during long-term operation, compromising system stability. To address these challenges, this study proposes a decision-time learning and planning integrated framework for MHBC control. Specifically, an innovative latent model embedding decision-time learning is designed for system identification, separately managing system uncertainties to fine-tune the model output. Furthermore, a decision-time planning algorithm is developed and the planning process is further guided by incorporating a value network and an enhanced online policy. Experimental results demonstrate that the proposed decision-time learning and planning integrated approaches achieve notable performance in MHBC control.

Introduction: The authors of the article reviewed the available scientific literature, library resource bases and media reports in order to present the topic of safety in the hyperbaric environment and fire accidents in hyperbaric chambers. Since the topic of the safety of the use of the chambers in the context of the threat to the life and health of both patients, staff and safe personnel is an important medical issue, an attempt was made to present the topic, description of accidents and numerous observations were made. Material and methods: Review of scientific literature and multimedia materials from the library collections. Results: A fire in a hyperbaric chamber, which exposes patients, staff and technical staff to the risk of loss of health and life, is the lack of compliance with procedures and the use of adequate algorithms based on them.

This article presents a description of the water cooling system in the pool of the \"Kobuz\" decompression chamber constituting a part of the DGKN-120 hyperbaric simulator used at the Department of Underwater Works Technologies of the Naval Academy in Gdynia.

This work describes an innovative simulator for clinical hyperbaric chambers that addresses critical training gaps in hyperbaric medicine. The system provides medical and technical personnel with a risk-free environment to develop essential operational skills without endangering patients or costly equipment. The simulator employs a dual-module architecture with web-based accessibility, intuitive controls for realistic chamber operation, and robust administrative capabilities. To evaluate the effectiveness of the simulator in the training process, we conducted a pilot study with clinical professionals. This study demonstrated significant improvements in procedural proficiency and emergency response capabilities, with participants showing measurable skill enhancement after simulator-based training sessions. The preliminary quantitative assessments revealed high educational value of proposed simulation software. This technological advancement represents a substantial contribution to hyperbaric medicine education, supporting both initial training and ongoing competency maintenance for clinical and technical operators in this specialized medical field.

Most cases of decompression sickness (DCS) occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48 h after surfacing for DCS and second, to evaluate the different treatment protocols. From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48 h) for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48 h after surfacing at the same hyperbaric institute. There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07) compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation. Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6.

Wild strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested in an experimental hyperbaric chamber to determine the possible effect of hyperbaric oxygen on the susceptibility of these strains to the antibiotics ampicillin, ampicillin + sulbactam, cefazolin, cefuroxime, cefoxitin, gentamicin, sulfamethoxazole + trimethoprim, colistin, oxolinic acid, ofloxacin, tetracycline, and aztreonam during their cultivation at 23 °C and 36.5 °C. Ninety-six-well inoculated microplates with tested antibiotics in Mueller–Hinton broth were cultured under standard incubator conditions (normobaric normoxia) for 24 h or in an experimental hyperbaric chamber (HAUX, Germany) for 24 h at 2.8 ATA of 100% oxygen (hyperbaric hyperoxia). The hyperbaric chamber was pressurised with pure oxygen (100%). Both cultures (normoxic and hyperoxic) were carried out at 23 °C and 36.5 °C to study the possible effect of the cultivation temperature. No significant differences were observed between 23 and 36.5 °C cultivation with or without the 2-h lag phase in Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Cultivation in a hyperbaric chamber at 23 °C and 36.5 °C with or without a 2-h lag phase did not produce significant changes in the minimum inhibitory concentration (MIC) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. For the tested strains of Pseudomonas aeruginosa, the possible effect of hyperbaric oxygen on their antibiotic sensitivity could not be detected because the growth of these bacteria was completely inhibited by 100% hyperbaric oxygen at 2.8 ATA under all hyperbaric conditions tested at 23 °C and 36.5 °C. Subsequent tests with wild strains of pseudomonads, burkholderias, and stenotrophomonads not only confirmed the fact that these bacteria stop growing under hyperbaric conditions at a pressure of 2.8 ATA of 100% oxygen but also indicated that inhibition of growth of these bacteria under hyperbaric conditions is reversible.

Decompression sickness is a fatal disease worldwide. Therefore, to find a prophylactic modality for decompression sickness is urgently required. Bone marrow derived mesenchymal stem cells exhibit effectiveness in antioxidant, anti-inflammation, and decrease cell death; while its effects on decompression sickness remains unclear. This study aimed to further investigate the mechanisms of decompression sickness induced lung injury, as well as effects of bone marrow derived mesenchymal stem cells on decompression sickness induced lung injury and explore the role of oxidative stress, inflammation and cell death play in this disease. The study involved Sprague-Dawley rats age at 8−10 weeks weighting 350 ± 10g. Acute lung injury was induced by decompression hyperbaric chamber. A dose of bone marrow derived mesenchymal stem cells (2 × 10 6 cells) was given to rats one day prior to the start of decompression. Lung injury severity was estimated by determining lung damage scores, pulmonary oxidative, inflammatory factors and cell death. In bone marrow derived mesenchymal stem cells treated rats, the morbidity and mortality of decompression markedly decreased. The increases of protein IL-1 and IL-6 in BALF and lung wet/dry ratio and lung injury score were alleviated. The ROS, CAT, SOD, and MDA activities and GSH levels were significant attenuated (P < 0.05). The pyroptosis and nerroptosis were significant mitigate (P < 0.05). Based on the results, bone marrow derived mesenchymal stem cells is an potential efficient and safe prophylactic modality protect rats from decompression induced acute lung injury.

In order to provide a better understanding of the phenomena that define the weld bead penetration and melting rate of consumables in underwater welding, welds were developed with a rutile electrode in air welding conditions and at the simulated depths of 5 and 10 m with the use of a hyperbaric chamber and a gravity feeding system. In this way, voltage and current signals were acquired. Data processing involved the welding voltage, determination of the sum of the anodic and cathodic drops, calculation of the short-circuit factor, and determination of the melting rate. Cross-sectional samples were also taken from the weld bead to assess bead geometry. As a result, the collected data show that the generation of energy in the arc–electrode connection in direct polarity (direct current electrode negative-DCEN) is affected by the hydrostatic pressure, causing a loss of fusion efficiency, a drop of operating voltage, decreased arc length, and increased number of short-circuit events. The combination of these characteristics kept the weld bead geometry unchanged, compared to dry weld conditions. With the positive electrode (direct current electrode positive-DCEP), radial losses were derived from greater arc lengths resulting from increasing hydrostatic pressure, which led to a decrease in weld penetration.