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AbstractBreath-hold divers, also known as freedivers, are at risk of specific injuries that are unique from those of surface swimmers and compressed air divers. Using peer-reviewed scientific research and expert opinion, we created a guide for medical providers managing breath-hold diving injuries in the field. Hypoxia induced by prolonged apnea and increased oxygen uptake can result in an impaired mental state that can manifest as involuntary movements or full loss of consciousness. Negative pressure barotrauma secondary to airspace collapse can lead to edema and/or hemorrhage. Positive pressure barotrauma secondary to overexpansion of airspaces can result in gas embolism or air entry into tissues and organs. Inert gas loading into tissues from prolonged deep dives or repetitive shallow dives with short surface intervals can lead to decompression sickness. Inert gas narcosis at depth is commonly described as an altered state similar to that experienced by compressed air divers. Asymptomatic cardiac arrhythmias are common during apnea, normally reversing shortly after normal ventilation resumes. The methods of glossopharyngeal breathing (insufflation and exsufflation) can add to the risk of pulmonary overinflation barotrauma or loss of consciousness from decreased cardiac preload. This guide also includes information for medical providers who are tasked with providing medical support at an organized breath-hold diving event with a list of suggested equipment to facilitate diagnosis and treatment outside of the hospital setting.

Breath-hold diving is a challenging activity that can lead to serious and dangerous complications, such as the "Taravana" syndrome. This syndrome is characterized by the onset of neurological symptoms after deep or repeated dives. The main clinical manifestations are cerebral, including stroke and cognitive impairment. The pathophysiology of Taravana syndrome is still widely debated, but the most accepted theory is that it is a specific form of decompression sickness. We have reviewed the main theories explaining the onset of Taravana syndrome and, through the description of a particularly illustrative case of a freediver using an underwater scooter, we have formulated a hypothesis according to which micro-bubbles formed directly in cerebral structures would be at the origin of this syndrome. MRI showed diffuse encephalopathy with vasogenic edema. Analysis of the radiological sequences did not suggest an ischemic or embolic mechanism. This finding is likely to be associated with the diagnosis of posterior reversible encephalopathy syndrome. The rapid ascent speeds associated with underwater scooter use could potentially result in the formation of nitrogen micro-bubbles in the capillaries of brain tissue. The emergence of scooters in freediving can be a hazard because of their ability to facilitate very rapid ascents. It is therefore essential to take preventive measures to ensure the safety of users of these devices. [ABSTRACT FROM AUTHOR]

SCUBA diving poses risks due to pressure changes during descent (compression) and ascent (decompression). Decompression sickness (DCS) occurs due to gas bubble formation as the pressure decreases, causing joint pain, numbness, dizziness, or even paralysis and death. Immediate treatment involves 100% oxygen to help eliminate inert gases and hyperbaric oxygen therapy (HBOT), which is essential to reduce gas emboli formation and inflammation, thus improving symptoms. We evaluated oxy-inflammation biomarkers in the saliva and urine of nine subjects pre- and post-technical dive on the Haven wreck (GE, Italy). A case of DCS occurred during the dive. The injured diver was treated immediately with O2 and transported to the hyperbaric center of "ASST Ospedale Ca Granda" in Milan. He was treated following the U.S. Navy Treatment Table 5 at 2.8 ATA and the day after with Table 15 at 2.4 ATA. Venous blood and urine samples were collected before and after each HBO treatment. Our study shows that dive increased oxy-inflammation biomarkers (ROS +126%; lipid peroxidation +23%; interleukins-6 +81%, -1β +19%, and TNFα +84%) and nitric oxide metabolites levels (+36%). HBOT after a DCS episode reduced oxidative stress, lowering the very high marker of lipid peroxidation (8-iso-PGF2α), and inhibited inflammatory interleukins. Overall, HBOT improved physiological responses in the diver affected by DCS. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Susceptibility to decompression sickness (DCS) is characterized by a wide inter-individual variability, the origins of which are still poorly understood. We selectively bred rats with at least a 3-fold greater resistance to DCS than standard rats after 6 generations. In order to better understand DCS mechanisms, we compared the static genome expression of these resistant rats from the 10th generation to their counterparts of the initial non-resistant Wistar strain, by a microarray transcriptomic approach coupled and crossed with a PCR plates miRnome study. Thus, we identified differentially expressed genes on selected males and females, as well as gender differences in those genes, and we crossed these transcripts with the respective targets of the differentially expressed microRNAs. Our results highlight pathways involved in inflammatory responses, circadian clock, cell signaling and motricity, phagocytosis or apoptosis, and they confirm the importance of inflammation in DCS pathophysiology. Static hepatic gene expression of resistant rats crossed with their circulating miRnome highlight the role of inflammatory pathways in the susceptibility and pathophysiology of decompression sickness. [ABSTRACT FROM AUTHOR]

Objectives: To retrospectively evaluate the correlation between intradiscal gas and infection in patients percutaneously biopsied for suspected discitis-osteomyelitis. Materials and methods: We retrospectively reviewed all CT-guided discitis-osteomyelitis biopsies performed between 2002 and 2022. Two independent trained musculoskeletal radiologists evaluated for presence of gas on CT and/or MRI within 1 week of the biopsy. Disagreements were resolved by a third musculoskeletal radiologist. CT was considered the gold standard for the detection of intradiscal gas. Pathology, microbiology, and imaging and clinical follow-up were used as the gold standard for presence of infection. Interrater agreement on CT and MRI, sensitivity, and positive predictive value were calculated, using the presence of gas as an indicator (test positive) for "no infection." Results: There were 284 biopsies in 275 subjects (mean age 58 ± 1.0 (range 4–99) years; 101 (37%) females and 174 (63%) males). Of the biopsies, 12 (4%) were cervical, 80 (28%) were thoracic, 192 (68%) were lumbar, and 200 (70%) were considered true discitis-osteomyelitis based on pathology, imaging, and clinical follow-up. Interrater agreement was excellent for CT (kappa = 0.83) and poor for MRI (kappa = − 0.021). The presence of gas had a 94% specificity and 76% negative predictive value for the absence of infection. Conclusion: CT is the preferred method for detecting intradiscal gas. The presence of gas means that discitis-osteomyelitis is unlikely. If intradiscal gas is present in the setting of discitis-osteomyelitis, the gas bubbles tend to be smaller and fewer in number. [ABSTRACT FROM AUTHOR]

Purpose: To observe the growth and resolution of decompression gas bubbles in the spinal cord of live rats in real time using MRI. Methods: We constructed an MRI‐compatible pressure chamber system to visualize gas bubble dynamics in deep tissues in real time. The system pressurizes and depressurizes rodents inside an MRI scanner and monitors their respiratory rate, heart rate, and body temperature while providing gaseous anesthesia under pressure during the experiments. Results: We observed the formation of decompression gas bubbles in the spinal cord of rats after compression to 7.1 bar absolute and rapid decompression inside the MRI scanner while maintaining continuous gaseous anesthesia and vital monitoring. Conclusion: We have shown the direct observation of decompression gas bubble formation in real time by MRI in live, anesthetized rats. [ABSTRACT FROM AUTHOR]

Freediving (synonyms: breath-hold diving, apnea diving) has become a popular leisure activity and continues to gain popularity and recognition as both a competitive and recreational sport. Formal freediving competitions are sanctioned by the international Confédération Mondiale des Activités Subaquatiques (CMAS) or the Association Internationale pour le Développement de l'Apnée (AIDA). Both organizations have set up rules and guidelines for competitive pool disciplines where athletes compete for maximum submerged breath-hold time or underwater swimming distance with or without fins. › In freshwater disciplines athletes strive for maximum depth using different freediving techniques. These aquatic breath-holding activities carry unique medical risks that are related to environmental factors eliciting extreme physiological challenges. Pool disciplines carry an increased risk of hypoxemia and, consequently, loss of consciousness, particularly in untrained individuals. Hypoxic complications are reported to occur in up to 10% of dives during freediving competitions. Shallow water blackout following hyperventilation to extend breathhold capability is a serious risk applying to all aquatic breath-hold activities, however, is more common during recreational freediving. › Deep freediving poses the athlete to further risks such as barotrauma of ear drums or lungs, immersion pulmonary edema, nitrogen narcosis, and decompression sickness when reaching great depths. While serious complications in competitive freediving are rare, however, the risk clearly rises with increasing depth. Special breathing techniques to increase lung volumes such as glossopharyngeal insufflation carry additional risks. › This article reviews possible complications and injury that may occur in competitive freedivers and discusses strategies for management and prevention of possible injury. [ABSTRACT FROM AUTHOR]

Aims: The primary objective of this investigation is to establish an animal model that accurately represents skeletal muscle injury as a consequence of decompression sickness. Additionally, this study aims to delineate the potential mechanisms underlying the development and progression of skeletal muscle damage associated with decompression sickness. Materials and methods: (1) In this research, rats were utilized as experimental models and subjected to 600 kPa pressure in an air medium for a duration of 60 min, followed by decompression at a consistent rate of 1.5 min to reach atmospheric pressure in order to establish an animal model for decompression injury. Assessment of decompression injury involved the observation of general symptoms and signs, as well as histopathological examination of lung tissue to determine the extent of damage in the pulmonary system of rats. (2) Building on the rat decompression injury model, we conducted pathological and serological examinations to assess the status of rat skeletal muscle. Additionally, we investigated the signaling mechanism of the TLR9-MyD88 pathway in mediating alterations in rat skeletal muscle resulting from decompression injury, and evaluated the effects of decompression injury on apoptosis in rat skeletal muscle. Results: Repeated decompression induces significant damage to skeletal muscle tissue, characterized by edema, fiber rupture, and atrophy. This process also leads to a transient elevation in creatine kinase (CK-MM) levels in rat serum, as well as an upregulation of proteins such as TLR9, MyD88, p38, and ERK in rat skeletal muscle tissue. Furthermore, repeated decompression results in a temporary increase in the transcription levels of Atrogen-1mRNA and MuRF-1mRNA in rat skeletal muscle tissue. Discussion: The decompression protocol applied in this study successfully induced decompression sickness in a rat model, leading to skeletal muscle damage that was consistent with the expected pathology of decompression injury. Despite the initial injury, the rats showed evidence of adaptation following prolonged exposure to decompression conditions. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Barotrauma is a frequent complication in patients with severe respiratory failure and is associated with poor outcomes. Extracorporeal membrane oxygenation (ECMO) implantation allows to introduce lung‐protective ventilation strategies that limit barotrauma development or progression, but available data are scarce. We performed a scoping review to summarize current knowledge on this therapeutic approach.We systematically searched PubMed/MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for studies investigating ECMO as a strategy to prevent/limit barotrauma progression in patients with respiratory failure. Pediatric studies, studies on perioperative implantation of ECMO, and studies not reporting original data were excluded. The primary outcome was the rate of barotrauma development/progression.We identified 21 manuscripts presenting data on a total of 45 ECMO patients. All patients underwent veno‐venous ECMO. Of these, 21 (46.7%) received ECMO before invasive mechanical ventilation. In most cases, ECMO implantation allowed to modify the respiratory support strategy (e.g., introduction of ultraprotective/low pressure ventilation in 12 patients, extubation while on ECMO in one case, and avoidance of invasive ventilation in 15 cases). Barotrauma development/progression occurred in <10% of patients. Overall mortality was 8/45 (17.8%).ECMO implantation to prevent barotrauma development/progression is a feasible strategy and may be a promising support option. [ABSTRACT FROM AUTHOR]

Background: The mechanism involved in HBO2 preconditioning in preventing inflammation in diving is still unclear. Syndecan-1, which is an important part of glycocalyx, has never been studied for its involvement in HBO2 preconditioning to prevent inflammation in decompression diving. This study aims to determine how HBO2 preconditioning impacts inflammation through Syndecan-1, MDA, and IL-1a markers. Method: This study is a true experimental post-test design. Forty male 12- to 14-year-old Sprague Dawley rats were divided into four groups. HBO2 and decompression diving were carried out in an animal hyperbaric chamber. All data were collected 12 and 24 hours after the decompression diving. Result: The incidence of decompression sickness was less frequent in the HBO2 preconditioning treatment group as opposed to the control group (4 vs 9) but did not reach a significant level (p > 0.05). All parameters showed no difference between the control and treatment groups 12 hours after the dive (p > 0.05). Twenty-four hours after diving, the treatment group demonstrated substantially elevated IL-1a levels in comparison to the control group (p = 0.030), and the increase of IL-1a in the treatment group is significant (p = 0.001). Although MDA levels did not reach significant, the treatment group's increase in MDA levels 24 hours after diving was greater than that of the control group. Meanwhile, The treatment group had a smaller reduction in Syndecan-1 levels in comparison to the control group following diving 24 hours later. Conclusion: HBO2 preconditioning prolongs the inflammation, as evidenced by increased levels of MDA, Syndecan-1, and IL-1a, even though it can prevent decompression sickness. Further research is needed to find the right time and dose of HBO2 preconditioning to shorten the inflammation time. [ABSTRACT FROM AUTHOR]

Eccentric upper‐body exercise performed 24 h prior to high‐altitude decompression has previously been shown to aggravate venous gas emboli (VGE) load. Yet, it is unclear whether increasing the muscle mass recruited (i.e., upper vs. whole‐body) during eccentric exercise would exacerbate the decompression strain. Accordingly, this study aimed to investigate whether the total muscle mass recruited during eccentric exercise influences the decompression strain. Eleven male participants were exposed to a simulated altitude of 24,000 ft for 90 min on three separate occasions. Twenty‐four hours before each exposure, participants performed one of the following protocols: (i) eccentric whole‐body exercise (ECCw; squats and arm‐cycling exercise), (ii) eccentric upper‐body exercise (ECCu; arm‐cycling), or (iii) no exercise (control). Delayed onset muscle soreness (DOMS) and isometric strength were evaluated before and after each exercise intervention. VGE load was evaluated at rest and after knee‐ and arm‐flex provocations using the 6‐graded Eftedal–Brubakk scale. Knee extensor (−20 ± 14%, P = 0.001) but not elbow flexor (−12 ± 18%, P = 0.152) isometric strength was reduced 24 h after ECCw. ECCu reduced elbow flexor isometric strength at 24 h post‐exercise (−18 ± 10%, P < 0.001). Elbow flexor DOMS was higher in the ECCu (median 6) compared with ECCw (5, P = 0.035). VGE scores were higher following arm‐flex provocations in the ECCu (median (range), 3 (0–4)) compared with ECCw (2 (0–3), P = 0.039) and control (0 (0–2), P = 0.011), and in ECCw compared with control (P = 0.023). VGE were detected earlier in ECCu (13 ± 20 min) compared with control (60 ± 38 min, P = 0.021), while no differences were noted between ECCw (18 ± 30 min) and control or ECCu. Eccentric exercise increased the decompression strain compared with control. The VGE load varied depending on the body region but not the total muscle mass recruited. Highlights: What is the central question of this study?Does exercise‐induced muscle damage (EIMD) resulting from eccentric exercise influence the presence of venous gas emboli (VGE) during a 90 min continuous exposure at 24,000 ft?What is the main finding and its importance?EIMD led to an earlier manifestation and greater VGE load compared with control. However, the decompression strain was dependent on the body region but not the total muscle mass recruited. [ABSTRACT FROM AUTHOR]

Diving accidents result from a variety of causes including human error, inadequate health and fitness, environmental hazards and equipment problems. They usually involve a cascade of events resulting in the diver being injured or deceased. The accuracy and usefulness of a diving accident investigation relies on well-targeted interviews, good field investigation, evidence collection and preservation, and appropriate equipment assessment. In the event of a fatality, a thorough and targeted autopsy is indicated. Investigators should have the appropriate knowledge, training, skills and support systems to perform the required tasks. Relevant investigations include the victim's medical and diving history, the dive circumstances and likely accident scenario, management of the accident including rescue and first aid, equipment inspection and testing and a thorough postmortem examination conducted by a forensic pathologist with an awareness of the special requirements of a diving autopsy and the knowledge to correctly interpret the findings. A chain of events analysis can determine the likely accident scenario, identify shortcomings and inform countermeasures. [ABSTRACT FROM AUTHOR]

This retrospective study analysed a series of investigations on lung function in military divers and the importance of computed tomography (CT) scans concerning fitness to dive. We examined the incidence of blebs and bullae in a population of military divers with large lungs prompted by six cases of pulmonary barotrauma. All of these divers' medicals were normal apart from having large lungs (FVC > 120% predicted). A subsequent survey of the database of all divers and submariners of the Royal Netherlands Navy (RNLN) found another 72 divers/submariners with large lungs who were then evaluated by a CT scan. This resulted in the identification of three further individuals with blebs and/or bullae, who were then declared unfit to dive. In total, the incidence of these lung abnormalities in this cohort was 11.5%. We discuss the possible consequences for fitness to dive with regard to the current literature on the subject, and also consider the most recent standards of reference values for pulmonary function indices. Based on our results and additional insights from other studies, we advise using the Global Lung Initiative reference values for pulmonary function, while performing high resolution CT scans only in divers with clinical indications. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Decompression sickness (DCS) is a medical condition caused by outgassing of dissolved nitrogen following rapid ascent by divers and aviators. Cutaneous DCS, historically termed cutis marmorata (CM), presents as a predominantly truncal reticular violaceous-to-dusky eruption. The prevailing theories for its pathogenesis include: localized cutaneous outgassing, paradoxical embolism across a right-to-left shunt (RLS), and brainstem emboli disrupting autonomic control of cutaneous microcirculation. METHODS: We conducted a systematic review of reports of cutaneous DCS to investigate relationships among CM, RLS, and neurological sequelae to better elucidate the mechanism of CM. A literature search examining reports of cutaneous DCS yielded 31 eligible studies, comprising a pooled total of 128 patients. RESULTS: Of the patients with documented workup, 84% showed evidence of RLS with CM. Subsequently 18 patients underwent percutaneous closure of intracardiac RLS with no recurrence of DCS. Of the patients with documented neurological evaluations, 57% experienced both CM and neurological DCS manifestations. The coexistence of RLS and neurological symptoms with CM was noted in numerous cases; exact percentages of overlap cannot be stated due to data unavailability. DISCUSSION: Our results indicating the striking coexistence of RLS and neurological sequelae in CM patients is supportive of the paradoxical embolism theory of pathogenesis. The frequent coincidence of CM with RLS and neurological symptoms raises concern that CM may signify vulnerability to devastating systemic gas emboli. CM has historically been considered trivial and self-limiting; however, our results support reappraisal of its clinical significance and potential reclassification to the more severe subtype. [ABSTRACT FROM AUTHOR]

Abstract Eccentric upper‐body exercise performed 24 h prior to high‐altitude decompression has previously been shown to aggravate venous gas emboli (VGE) load. Yet, it is unclear whether increasing the muscle mass recruited (i.e., upper vs. whole‐body) during eccentric exercise would exacerbate the decompression strain. Accordingly, this study aimed to investigate whether the total muscle mass recruited during eccentric exercise influences the decompression strain. Eleven male participants were exposed to a simulated altitude of 24,000 ft for 90 min on three separate occasions. Twenty‐four hours before each exposure, participants performed one of the following protocols: (i) eccentric whole‐body exercise (ECCw; squats and arm‐cycling exercise), (ii) eccentric upper‐body exercise (ECCu; arm‐cycling), or (iii) no exercise (control). Delayed onset muscle soreness (DOMS) and isometric strength were evaluated before and after each exercise intervention. VGE load was evaluated at rest and after knee‐ and arm‐flex provocations using the 6‐graded Eftedal–Brubakk scale. Knee extensor (−20 ± 14%, P = 0.001) but not elbow flexor (−12 ± 18%, P = 0.152) isometric strength was reduced 24 h after ECCw. ECCu reduced elbow flexor isometric strength at 24 h post‐exercise (−18 ± 10%, P

Hydration status refers to the balance between the intake and discharge of water in the body. When the ingested and discharged water are roughly equal and the body is in water balance, it is the normal hydration status, and when the water intake is too little or too much, it is the "dehydration" or "overhydration status". The hydration status of the body not only affects metabolism, but also affects the functions of the urinary system, cardiovascular system, nervous system, etc. In order to further clarify the relationship between body hydration status and decompression sickness (DCS), this paper reviewed relevant studies and analyzed the interaction between hydration and decompression safety during diving. The primary causes of dehydration in diving are "hyperbaric diuresis", "immersion diuresis", breathing dry gas, heat, and cold. Dehydration not only promotes the occurrence of DCS but also reduces the aerobic work efficiency and athletic performance of divers, as well as affects cognition and mood. A study found that appropriate rehydration before and during diving can reduce the risk of DCS, which possibly associates with the increase of blood volume, plasma surface tension, and vasoconstriction. Fluid therapy is also important for those who already have DCS. This paper analyzed the amount, nature, timing, and effect of rehydration involved in the above links, comprehensively sorted out the relationship between hydration and diving safety, summarized the existing problems, and provided reference for practical application and future research.

Abstract Background Extracorporeal membrane oxygenation (ECMO) is increasingly being used for critically ill patients with cardiopulmonary failure. Air in the ECMO circuit is an emergency, a rare but fatal complication. Case presentation We introduce a case of a 76-year-old female who suffered from cardiac arrest complicated with severe trauma and was administered veno-arterial extracorporeal membrane oxygenation. In managing the patient with ECMO, air entered the ECMO circuit, which had not come out nor was folded or broken. Although the ECMO flow was quickly re-established, the patient died 6 h after initiating ECMO therapy. Conclusions In this case report, the reason for the complication is drainage insufficiency. This phenomenon is similar to decompression sickness. Understanding this complication is very helpful for educating the ECMO team for preventing this rare but devastating complication of fatal decompression sickness in patients on ECMO.

We report a case of an active-duty diver who developed severe decompression sickness with concomitant patent foramen ovale that was successfully closed contrary to standard guideline recommendations. This case should prompt evaluation of the role of cardiac screening in occupational divers, including tactical athletes, relative to recreational divers. [ABSTRACT FROM AUTHOR]

Objective: To discuss the link between inner ear decompression sickness and patent foramen ovale. Materials and methods: Monocentric and retrospective study on decompression sickness of the inner ear requiring hyperbaric chamber treatment, from 2014 to 2021. Results: Sixty-one patients of inner ear decompression sickness were included in this study. Twenty-four patients had vestibular injuries, 28 cochlear injuries and 9 cochleo-vestibular injuries. Compression chamber treatment was given, using an oxygen–helium mixture with oxygen partial pressure (PIO2) limited to 2.8 atmosphere absolute (ATA). All vestibular accidents completely recovered without clinical sequelae. For cochlear accident only 10 out of 37 patients (27%) recovered completely. A right–left shunt (patent foramen oval or intra-pulmonary shunt) was found in 31.1% of patients with inner ear decompression sickness (p > 0.05). Conclusion: The presence of patent foramen oval in patients with inner ear decompression was not statistically significant in our study. Understanding of the pathophysiology of decompression illness and the physiology and anatomy of the labyrinth would suggest a mechanism of supersaturation with degassing in intra-labyrinthine liquids. [ABSTRACT FROM AUTHOR]

Nanoparticle-mediated histotripsy (NMH) is a novel ablation method that combines nanoparticles as artificial cavitation nuclei with focused ultrasound pulsing to achieve targeted, non-invasive, and cell-selective tumor ablation. The study described here examined the effect of dual-frequency histotripsy pulsing on the cavitation threshold, bubble cloud characteristics, and ablative efficiency in NMH. High-speed optical imaging was used to analyze bubble cloud characteristics and to measure ablation efficiency for NMH inside agarose tissue phantoms containing perfluorohexane-filled nanocone clusters, which were previously developed to reduce the histotripsy cavitation threshold for NMH. Dual-frequency histotripsy pulsing was applied at a 1:1 pressure ratio using a modular 500 kHz and 3 MHz dual-frequency array transducer. Optical imaging results revealed predictable, well-defined bubble clouds generated for all tested cases with similar reductions in the cavitation thresholds observed for single-frequency and dual-frequency pulsing. Dual-frequency pulsing was seen to nucleate small, dense clouds in agarose phantoms, intermediate in size of their component frequencies but closer in area to that of the higher component frequency. Red blood cell experiments revealed complete ablations were generated by dual-frequency NMH in all phantoms in <1500 pulses. This result was a significant increase in ablation efficiency compared with the ∼4000 pulses required in prior single-frequency NMH studies. Overall, this study indicates the potential for using dual-frequency histotripsy methods to increase the ablation efficacy of NMH. [ABSTRACT FROM AUTHOR]

Objective: Evaluation of tumor microvascular morphology is of great significance in tumor diagnosis, therapeutic effect prediction, and surgical planning. Recently, two-dimensional ultrasound localization microscopy (2DULM) has demonstrated its superiority in the field of microvascular imaging. However, it suffers from planar dependence and is unintuitive. We propose a novel three-dimensional ultrasound localization microscopy (3DULM) to avoid these limitations. Methods: We investigated 3DULM based on a 2D array for tumor microvascular imaging. After intravenous injection of contrast agents, all elements of the 2D array transmit and receive signals to ensure a high and stable frame rate. Microbubble signal extraction, filtering, positioning, tracking, and other processing were used to obtain a 3D vascular map, flow velocity, and flow direction. To verify the effectiveness of 3DULM, it was validated on double helix tubes and rabbit VX2 tumors. Cisplatin was used to verify the ability of 3DULM to detect microvascular changes during tumor treatment. Results: In vitro, the sizes measured by 3DULM at 3 mm and 13 mm were 178 μ m and 182 μ m , respectively. In the rabbit tumors, we acquired 9000 volumes to reveal vessels about 30 μ m in diameter, which surpasses the diffraction limit of ultrasound in traditional ultrasound imaging, and the results matched with micro-angiography. In addition, there were significant changes in vascular density and curvature between the treatment and control groups. Conclusions: The effectiveness of 3DULM was verified in vitro and in vivo. Hence, 3DULM may have potential applications in tumor diagnosis, tumor treatment evaluation, surgical protocol guidance, and cardiovascular disease. Clinical relevance statement: 3D ultrasound localization microscopy is highly sensitive to microvascular changes; thus, it has clinical potential for tumor diagnosis and treatment evaluation. Key Points: • 3D ultrasound localization microscopy is demonstrated on double helix tubes and rabbit VX2 tumors. • 3D ultrasound localization microscopy can reveal vessels about 30 μ m in diameter—far smaller than traditional ultrasound. • This form of imaging has potential applications in tumor diagnosis, tumor treatment evaluation, surgical protocol guidance, and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Copyright of Anatolian Journal of General Medical Research is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background Decompression sickness (DCS) is a well-known risk associated with scuba diving, particularly in people with right-to-left shunt, such as patent foramen oval (PFO). Herein, we present a unique case of late PFO permeabilization after closure. Case summary A 26-year-old male diver was diagnosed with DCS following a dive at 36 m. He underwent PFO closure with a STARFLEX® prosthesis. Ten years later, the patient was presented with recurrent manifestations suggestive of DCS. The performed diagnostic work-up detects a permeabilization of the implanted prosthesis, and he was treated with a conservative approach. Discussion This case highlights the challenges in the management of PFO in divers and raises concerns about the long-term efficiency of PFO closure and the impact of diving-related factors on prosthesis patency. [ABSTRACT FROM AUTHOR]

Decompression sickness (DCS) is a systemic syndrome that can occur after an environmental pressure reduction. Previously, we showed that the plasmatic tetrameric form of transthyretin (TTR) nearly disappeared in rats suffering DCS but not in asymptomatic ones. In this pilot study, we assessed whether the resistance to DCS could be associated with polymorphism of the gene of TTR. For this study, Sanger sequencing was performed on purified PCR products from the liver of 14‐week‐old male and female standard and DCS‐resistant rats (n = 5 per group). Hepatic TTR mRNA expression was assessed by RT‐qPCR in 18–19 week‐old male and female standard and resistant rats (n = 6 per group). There is a synonymous single nucleotide polymorphism (SNP) on the third base of codon 46 (c.138 C > T). The thymine allele was present in 90% and 100% of males and females standard, respectively. However, this allele is present in only 30% of DCS‐resistant males and females (p = 0.0002301). In the liver, there is a significant effect of the resistance to DCS (p = 0.043) and sex (p = 0.047) on TTR expression. Levels of TTR mRNA were lower in DCS‐resistant animals. To conclude, DCS resistance might be associated with a SNP and a lower expression of TTR. [ABSTRACT FROM AUTHOR]

Background: Respiratory failure following COVID-19 can lead to the death of COVID patients. Monitoring these patients during their ventilation is essential. The present study investigated the effect of measuring esophageal pressure in preventing barotrauma while receiving Noninvasive Positive Pressure Ventilation (NIPPV) in patients with COVID-19. Methods: The present study is a single-blind clinical trial conducted on patients with COVID-19 hospitalized in the Intensive Care Unit (ICU). The patients were divided into two groups; one group had their esophageal pressure measured while receiving NIPPV, their ventilation was adjusted based on this pressure, and the second group was only ventilated according to anesthesia protocols. Finally, the data was entered into SPSS V.23 software and analyzed according to the study's objectives. Results: The results of the present study showed that the incidence of subcutaneous emphysema-type barotrauma in the Esophageal Pressure (EP) monitoring group was lower than in the non-Esophageal Pressure (nEP) monitoring group. Also, the IPAP level in the EP group was lower than in NEP. The incidence of complications such as abdominal bloating and gavage intolerance was lower in EP than in NEP. The blood oxygen level in NEP was higher than in EP, but there was no significant difference between them. Conclusion: Esophageal pressure measurement in patients with COVID-19 receiving NIPPV can reduce barotrauma in the patients. [ABSTRACT FROM AUTHOR]

Objective: To understand the role of a single laryngologist, Andrew Heermance Smith, in elucidating the mechanisms of Caisson Disease and controlling it effects on bridge workers. Data Sources: Scientific and lay publications, letters and records of the Roebling family, obituaries and internet sources. Review Methods: Historical review. Results: AH Smith combined physiological observations and experiments in the Brooklyn Bridge caissons with a review of the existing engineering and medical literature to describe the Caisson Disease and to devise strategies to ameliorate its effects. Conclusion: Despite an incorrect conclusion about the pathophysiology of decompression sickness, Smith's stringent standards and timely interventions allow completion of the masonry towers of the Brooklyn Bridge. Level of Evidence: NA Laryngoscope, 134:3044–3048, 2024 [ABSTRACT FROM AUTHOR]

We hypothesized that early intra-central nervous system (CNS) responses in a murine model of decompression sickness (DCS) would be reflected by changes in the microparticles (MPs) that exit the brain via the glymphatic system, and due to systemic responses the MPs would cause inflammatory changes lasting for many days leading to functional neurological deficits. Elevations on the order of threefold of blood-borne inflammatory MPs, neutrophil activation, glymphatic flow, and neuroinflammation in cerebral cortex and hippocampus were found in mice at 12 days after exposure to 760 kPa of air for 2 h. Mice also exhibited a significant decline in memory and locomotor activity, as assessed by novel object recognition and rotarod testing. Similar inflammatory changes in blood, neuroinflammation, and functional impairments were initiated in naïve mice by injection of filamentous (F-) actin-positive MPs, but not F-actin-negative MPs, obtained from decompressed mice. We conclude that high pressure/decompression stress establishes a systemic inflammatory process that results in prolonged neuroinflammation and functional impairments in the mouse decompression model. NEW & NOTEWORTHY: Elevated glymphatic flow due to astrocyte and microglial activation from high-pressure exposure triggers release of microparticles (MPs) to the circulation where neutrophil activation and production of filamentous (F)-actin expressing MPs result in a persistent feed-forward neuroinflammatory cycle and functional deficits lasting for at least 12 days. [ABSTRACT FROM AUTHOR]

This document provides summaries of various studies and initiatives related to Hyperbaric Oxygen Therapy (HBO2). One study found that adjunctive treatments with NBP or DXM were more effective than HBO2 alone for treating DNS from CO poisoning. Another study examined the prevention of middle ear barotrauma during HBO2 and found diverse practices among facilities. A physiological model for decompression sickness (DCS) presentations was also proposed. Additionally, the text discusses the use of HBO2 for soft tissue radiation injury and the potential benefits for treating sexual dysfunction. Lastly, a care process model and text alert system were implemented to increase the consultation rate for HBO2 treatment of carbon monoxide poisoning. [Extracted from the article]

The document titled "Diving Operations" provides summaries of four research studies related to diving decompression sickness. The studies cover a range of topics, including the use of wearable ultrasound technology to detect decompression bubbles in real-time, genomic expression patterns in divers with decompression sickness, the effectiveness of different decompression stops, and the physiological effects of deep closed-circuit rebreather mixed gas diving. The studies explore various aspects of decompression sickness, such as inflammatory processes, gas bubble formation, venous gas emboli, and immune responses. These findings contribute to our understanding of decompression sickness and potential ways to mitigate its risks. [Extracted from the article]

Studies suggest that COVID-19 infections may have longer-term and more significant complications, even with mild or absent symptoms. This may predispose divers to pulmonary barotrauma, arterial gas embolisms, and reduced exercise tolerance, and impact physical and cognitive performance during diving. Military diving is physically, physiologically, and psychologically taxing on the individual. This study aims to assess the incidence of complications after COVID-19 infections in a cohort of active military divers and the incidence of diving-related injuries such as decompression sickness and barotrauma following recovery from acute COVID-19 infections. A single-center, retrospective cohort study of complications after COVID-19 infections was done in a cohort of the Republic of Singapore Navy (RSN) Naval Diving Unit (NDU) Divers and involved the collection of retrospective data for 329 military divers who were diagnosed with COVID-19 infection from 25 Mar 2020 and 13 Feb 2023. We found no clinical or subclinical complications after COVID-19 infection in our fully vaccinated, low-risk population of NDU divers after asymptomatic or mild COVID-19 infection. There were also no incidences of diving-related injuries related to COVID-19 after recovery from the acute illness. Based on the study results, it is recommended that all military divers with asymptomatic or mild COVID-19 infections return to military diving activities immediately after recovery from acute COVID-19 infection with resolution of symptoms. As existing guidelines recommend, divers with moderate to critical COVID-19 infection should be reviewed by a diving physician and undergo necessary investigations before returning to military diving. [ABSTRACT FROM AUTHOR]

A blood component analysis is an early step for evaluating inflammatory disorders, but it can be unfeasible in some settings. This pilot study assessed whether extracellular vesicle (EV) changes in perspiration are parallel to those occurring in blood as an alternative or complementary option to diagnose an inflammatory response. In parallel studies, EVs were analyzed in perspiration and blood obtained before and after five self-contained underwater breathing apparatus (SCUBA) divers at the National Aquarium in Baltimore performed a dive to 3.98 m of sea water for 40 min, and five non-divers performed an exercise routine at ambient atmospheric pressure. The results demonstrated that microparticles (MPs) are present in perspiration, their numbers increase in the blood in response to SCUBA diving, and the interleukin (IL)-1β content increases. In contrast, while blood-borne MPs became elevated in response to terrestrial exercise, no statistically significant increases occurred in perspiration, and there were no changes in IL-1β. There were no statistically significant elevations in the exosomes in perspiration or blood in response to SCUBA diving and few changes following terrestrial exercise. These findings suggest that an MP perspiration analysis could be a non-invasive method for detecting inflammatory responses that can occur due to the oxidative stress associated with SCUBA diving. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal membrane oxygenation (ECMO) is increasingly being used for critically ill patients with cardiopulmonary failure. Air in the ECMO circuit is an emergency, a rare but fatal complication. Case presentation: We introduce a case of a 76-year-old female who suffered from cardiac arrest complicated with severe trauma and was administered veno-arterial extracorporeal membrane oxygenation. In managing the patient with ECMO, air entered the ECMO circuit, which had not come out nor was folded or broken. Although the ECMO flow was quickly re-established, the patient died 6 h after initiating ECMO therapy. Conclusions: In this case report, the reason for the complication is drainage insufficiency. This phenomenon is similar to decompression sickness. Understanding this complication is very helpful for educating the ECMO team for preventing this rare but devastating complication of fatal decompression sickness in patients on ECMO. [ABSTRACT FROM AUTHOR]

Background: Temporomandibular disease (TMD) is commonly seen, and divers also experience pain in the temporomandibular joint (TMJ) or masticatory muscles. This article aims to provide a tool for diving physicians or medical professionals involved in diving medicine since jaw pain among divers is a pertinent subject and can be challenging to evaluate without some background in dentistry or maxillofacial surgery. Method: A basic algorithm was developed to provide a tool to differentiate jaw pains experienced by divers. Three brief case studies were developed, and five diving physicians were tasked with diagnosing the cases using the algorithm. Additionally, simple exercises and massage techniques that can benefit patients with TMD, particularly immediately after diving, are outlined. Results: All five diving physicians successfully diagnosed the cases using the algorithm. However, three of them were unable to diagnose the first case (disc luxation) without consulting the algorithm. Nevertheless, all physicians acknowledged the utility of the algorithm. Conclusions: Jaw pain in divers can stem from diverse causes, but effective treatment options exist. Our study findings provide valuable insights to assist diving physicians in making accurate diagnoses and guiding appropriate patient management, which may include referrals to specialists such as dentists, maxillofacial surgeons, or orthodontists. [ABSTRACT FROM AUTHOR]

Patent foramen ovale (PFO) is a remnant of the foetal circulation resulting from incomplete occlusion of the septum primum and septum secundum. Although prevalent in about 25% of the population, it mainly remains asymptomatic. However, its clinical significance in situations such as cryptogenic stroke, migraine, and decompression illness (DCI) has been well described. Recent randomised clinical trials (RCTs) have demonstrated the efficacy of percutaneous PFO closure over pharmacological therapy alone for secondary stroke prevention in carefully selected patients. Notably, these trials have excluded older patients or those with concurrent thrombophilia. Furthermore, the role of closure in other clinical conditions associated with PFO, like decompression sickness (DCS) and migraines, remains under investigation. Our review aims to summarise the existing literature regarding epidemiology, pathophysiological mechanisms, optimal management, and closure indications for these special patient groups. [ABSTRACT FROM AUTHOR]

We report a compressed air worker who had diffuse cutaneous decompression sickness with pain in his left shoulder and visual disturbance characteristic of migraine aura after only his third hyperbaric exposure. The maximum pressure was 253 kPa gauge with oxygen decompression using the Swanscombe Oxygen Decompression Table. He was found to have a very large right-to-left shunt across a 9 mm atrial septal defect. He had transcatheter closure of the defect but had some residual shunting with release of a Valsalva manoeuvre. Thirty-two other tunnel workers undertook the same pressure profile and activities in the same working conditions during the maintenance of a tunnel boring machine for a total of 233 similar exposures and were unaffected. As far as we are aware this is the first report of shunt-mediated decompression sickness in a hyperbaric tunnel worker in the United Kingdom and the second case reported worldwide. These cases suggest that shuntmediated decompression sickness should be considered to be an occupational risk in modern compressed air working. A right-to-left shunt in a compressed air worker should be managed in accordance with established clinical guidance for divers. [ABSTRACT FROM AUTHOR]

Introduction: Inhalation of high concentrations of carbon dioxide (CO2) at atmospheric pressure can be toxic with dosedependent effects on the cardiorespiratory system or the central nervous system. Exposure to both hyperbaric and hypobaric environments can result in decompression sickness (DCS). The effects of CO2 on DCS are not well documented with conflicting results. The objective was to review the literature to clarify the effects of CO2 inhalation on DCS in the context of hypobaric or hyperbaric exposure. Methods: The systematic review included experimental animal and human studies in hyper- and hypobaric conditions evaluating the effects of CO2 on bubble formation, denitrogenation or the occurrence of DCS. The search was based on MEDLINE and PubMed articles with no language or date restrictions and also included articles from the underwater and aviation medicine literature. Results: Out of 43 articles, only 11 articles were retained and classified according to the criteria of hypo- or hyperbaric exposure, taking into account the duration of CO2 inhalation in relation to exposure and distinguishing experimental work from studies conducted in humans. Conclusions: Before or during a stay in hypobaric conditions, exposure to high concentrations of CO2 favors bubble formation and the occurrence of DCS. In hyperbaric conditions, high CO2 concentrations increase the occurrence of DCS when exposure occurs during the bottom phase at maximum pressure, whereas beneficial effects are observed when exposure occurs during decompression. These opposite effects depending on the timing of exposure could be related to 1) the physical properties of CO2, a highly diffusible gas that can influence bubble formation, 2) vasomotor effects (vasodilation), and 3) anti-inflammatory effects (kinase-nuclear factor and heme oxygenase-1 pathways). The use of O2-CO2 breathing mixtures on the surface after diving may be an avenue worth exploring to prevent DCS. [ABSTRACT FROM AUTHOR]

Breath-hold diving is a challenging activity that can lead to serious and dangerous complications, such as the “Taravana” syndrome. This syndrome is characterized by the onset of neurological symptoms after deep or repeated dives. The main clinical manifestations are cerebral, including stroke and cognitive impairment. The pathophysiology of Taravana syndrome is still widely debated, but the most accepted theory is that it is a specific form of decompression sickness. We have reviewed the main theories explaining the onset of Taravana syndrome and, through the description of a particularly illustrative case of a freediver using an underwater scooter, we have formulated a hypothesis according to which micro-bubbles formed directly in cerebral structures would be at the origin of this syndrome. MRI showed diffuse encephalopathy with vasogenic edema. Analysis of the radiological sequences did not suggest an ischemic or embolic mechanism. This finding is likely to be associated with the diagnosis of posterior reversible encephalopathy syndrome. The rapid ascent speeds associated with underwater scooter use could potentially result in the formation of nitrogen micro-bubbles in the capillaries of brain tissue. The emergence of scooters in freediving can be a hazard because of their ability to facilitate very rapid ascents. It is therefore essential to take preventive measures to ensure the safety of users of these devices.

Apnea testing is a standard method when diagnosing brain or more specifically brainstem death; however, it is imperative to acknowledge the potential for lung injury during this procedure and follow clinical practice guideline recommendations that may reduce the risk of complications. Two cases of barotrauma leading to pneumothorax occurred during apnea tests that used higher‐than‐recommended oxygen flow rates. Additional data are necessary to clarify the mechanism and incidence of this life‐threatening complication. [ABSTRACT FROM AUTHOR]

Abstract Background Cetaceans, having experienced prolonged adaptation to aquatic environments, have undergone evolutionary changes in their respiratory systems. This process of evolution has resulted in the emergence of distinctive phenotypic traits, notably the abundance of elastic fibers and thickened alveolar walls in their lungs, which may facilitate alveolar collapse during diving. This structure helps selective exchange of oxygen and carbon dioxide, while minimizing nitrogen exchange, thereby reducing the risk of DCS. Nevertheless, the scientific inquiry into the mechanisms through which these unique phenotypic characteristics govern the diving behavior of marine mammals, including cetaceans, remains unresolved. Results This study entails an evolutionary analysis of 42 genes associated with pulmonary fibrosis across 45 mammalian species. Twenty-one genes in cetaceans exhibited accelerated evolution, featuring specific amino acid substitutions in 14 of them. Primarily linked to the development of the respiratory system and lung morphological construction, these genes play a crucial role. Moreover, among marine mammals, we identified eight genes undergoing positive selection, and the evolutionary rates of three genes significantly correlated with diving depth. Specifically, the SFTPC gene exhibited convergent amino acid substitutions. Through in vitro cellular experiments, we illustrated that convergent amino acid site mutations in SFTPC contribute positively to pulmonary fibrosis in marine mammals, and the presence of this phenotype can induce deep alveolar collapse during diving, thereby reducing the risk of DCS during diving. Conclusions The study unveils pivotal genetic signals in cetaceans and other marine mammals, arising through evolution. These genetic signals may influence lung characteristics in marine mammals and have been linked to a reduced risk of developing DCS. Moreover, the research serves as a valuable reference for delving deeper into human diving physiology.

Background: Preclinical studies have demonstrated that tumour cell death can be enhanced 10- to 40-fold when radiotherapy is combined with focussed ultrasound-stimulated microbubble (FUS-MB) treatment. The acoustic exposure of microbubbles (intravascular gas microspheres) within the target volume causes bubble cavitation, which induces perturbation of tumour vasculature and activates endothelial cell apoptotic pathways responsible for the ablative effect of stereotactic body radiotherapy. Subsequent irradiation of a microbubble-sensitised tumour causes rapid increased tumour death. The study here presents the mature safety and efficacy outcomes of magnetic resonance (MR)-guided FUS-MB (MRgFUS-MB) treatment, a radioenhancement therapy for breast cancer. Methods and findings: This prospective, single-center, single-arm Phase 1 clinical trial included patients with stages I–IV breast cancer with in situ tumours for whom breast or chest wall radiotherapy was deemed adequate by a multidisciplinary team (clinicaltrials.gov identifier: NCT04431674). Patients were excluded if they had contraindications for contrast-enhanced MR or microbubble administration. Patients underwent 2 to 3 MRgFUS-MB treatments throughout radiotherapy. An MR-coupled focussed ultrasound device operating at 800 kHz and 570 kPa peak negative pressure was used to sonicate intravenously administrated microbubbles within the MR-guided target volume. The primary outcome was acute toxicity per Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Secondary outcomes were tumour response at 3 months and local control (LC). A total of 21 female patients presenting with 23 primary breast tumours were enrolled and allocated to intervention between August/2020 and November/2022. Three patients subsequently withdrew consent and, therefore, 18 patients with 20 tumours were included in the safety and LC analyses. Two patients died due to progressive metastatic disease before 3 months following treatment completion and were excluded from the tumour response analysis. The prescribed radiation doses were 20 Gy/5 fractions (40%, n = 8/20), 30 to 35 Gy/5 fractions (35%, n = 7/20), 30 to 40 Gy/10 fractions (15%, n = 3/20), and 66 Gy/33 fractions (10%, n = 2/20). The median follow-up was 9 months (range, 0.3 to 29). Radiation dermatitis was the most common acute toxicity (Grade 1 in 16/20, Grade 2 in 1/20, and Grade 3 in 2/20). One patient developed grade 1 allergic reaction possibly related to microbubbles administration. At 3 months, 18 tumours were evaluated for response: 9 exhibited complete response (50%, n = 9/18), 6 partial response (33%, n = 6/18), 2 stable disease (11%, n = 2/18), and 1 progressive disease (6%, n = 1/18). Further follow-up of responses indicated that the 6-, 12-, and 24-month LC rates were 94% (95% confidence interval [CI] [84%, 100%]), 88% (95% CI [75%, 100%]), and 76% (95% CI [54%, 100%]), respectively. The study's limitations include variable tumour sizes and dose fractionation regimens and the anticipated small sample size typical for a Phase 1 clinical trial. Conclusions: MRgFUS-MB is an innovative radioenhancement therapy associated with a safe profile, potentially promising responses, and durable LC. These results warrant validation in Phase 2 clinical trials. Trial registration: clinicaltrials.gov, identifier NCT04431674. Daniel Moore-Palhares and team present the mature safety and efficacy outcomes of magnetic resonance-guided focussed ultrasound-stimulated microbubble (MRgFUS-MB) treatment, a radioenhancement therapy for breast cancer. Author summary: Why was this study done?: Preclinical studies demonstrated combining radiotherapy with focused ultrasound-stimulated microbubble treatment (FUS-MB) enhances tumour cell death by 10 to 40 times, suggesting a promising radioenhancement therapy. Explanation: The exposure of microbubbles (intravascular gas microspheres) to acoustic waves leads to bubble cavitation, disrupting tumour vasculature and triggering endothelial cell apoptotic pathways. Subsequent irradiation of a microbubble-sensitised tumour significantly increases tumour death. What did the researchers do and find?: This Phase 1 clinical trial analysed 18 patients with stages I–IV breast cancer with in situ tumours for whom breast or chest wall radiotherapy was conducted per standard-of-care. Patients underwent 2 to 3 sessions of magnetic resonance (MR)-guided FUS-MB treatment during their radiotherapy regimen. The MR-guided FUS-MB treatment demonstrated safety and achieved high rates of objective response and sustained long-term local control. What do these findings mean?: This is, to our knowledge, the first in-human clinical trial to demonstrate the effectiveness and safety of this radioenhancement therapy. This study opens new avenues for improving treatment outcomes in breast cancer and the possibility of replication in other primary malignancies. The safety and efficacy findings observed in this trial warrant validation in Phase 2 clinical trials. [ABSTRACT FROM AUTHOR]

Boerhaave's syndrome, also known as spontaneous esophageal rupture, is a rare but life-threatening condition characterized by a tear in the esophagus. It is most commonly caused by a sudden increase in intraesophageal pressure, often due to severe vomiting or retching. Early diagnosis of Boerhaave's syndrome is crucial for improving patient outcomes. The classic triad of symptoms includes severe chest pain, vomiting, and subcutaneous emphysema (air under the skin). However, not all patients present with this triad, and the diagnosis can be challenging, especially in patients without the typical symptoms. In this case report, we present the clinical details of a 52-year-old male patient who presented to the emergency department (ED) with severe abdominal pain and vomiting for several days. The patient had a history of chronic alcohol abuse and a recent episode of vigorous vomiting. [ABSTRACT FROM AUTHOR]

Simple Summary: Fishery interactions are the most serious conservation risk for sea turtles. The protection of threatened species such as sea turtles is necessary to maintain an ecosystem's resilience. With a record number of loggerhead sea turtle nests in 2023 in Spain and other Mediterranean countries, the Mediterranean basin is playing an important role in all stages of the loggerhead sea turtle's life-cycle. Apart from the main cause of admission for rehabilitation of sea turtles, it is necessary to consider the possibility of late-stage affections causing any alteration in the normal physiology or behavior of marine turtles. Osteolytic lesions are a frequent finding during the rehabilitation of sea turtles, and the causes and consequences of them must be studied. Osteolytic lesions in loggerhead sea turtles (Caretta caretta) during rehabilitation are attributed to multiple causes, including gas embolism, hypothermia, and osteomyelitis due to bacterial or fungal infection. This study reports the appearance of osteolytic lesions in a sub-adult loggerhead sea turtle with involvement of the right fore and hind flippers, visible swelling of the elbow and knee joints, and accompanied by lameness after 45 days of rehabilitation. Radiographs and computed tomography revealed multiple lytic bone lesions. This was the fourth rehabilitation admission of the turtle after being accidentally captured by trawler ships (bycatch) in 2019, 2020, 2022, and 2023. Potential causes were dysbaric osteonecrosis due to a past decompression sickness event and hypothermia with osteomyelitis from bacterial infection. Blood cultures and antibiotic susceptibility testing led to the isolation of Ewingella americana responsive to enrofloxacin. This study investigates extensive fore and hind flipper involvement in a sub-adult loggerhead turtle, aiming to determine causes and risk factors. The pathogenesis and significance of these lesions is discussed. [ABSTRACT FROM AUTHOR]

Background: Cetaceans, having experienced prolonged adaptation to aquatic environments, have undergone evolutionary changes in their respiratory systems. This process of evolution has resulted in the emergence of distinctive phenotypic traits, notably the abundance of elastic fibers and thickened alveolar walls in their lungs, which may facilitate alveolar collapse during diving. This structure helps selective exchange of oxygen and carbon dioxide, while minimizing nitrogen exchange, thereby reducing the risk of DCS. Nevertheless, the scientific inquiry into the mechanisms through which these unique phenotypic characteristics govern the diving behavior of marine mammals, including cetaceans, remains unresolved. Results: This study entails an evolutionary analysis of 42 genes associated with pulmonary fibrosis across 45 mammalian species. Twenty-one genes in cetaceans exhibited accelerated evolution, featuring specific amino acid substitutions in 14 of them. Primarily linked to the development of the respiratory system and lung morphological construction, these genes play a crucial role. Moreover, among marine mammals, we identified eight genes undergoing positive selection, and the evolutionary rates of three genes significantly correlated with diving depth. Specifically, the SFTPC gene exhibited convergent amino acid substitutions. Through in vitro cellular experiments, we illustrated that convergent amino acid site mutations in SFTPC contribute positively to pulmonary fibrosis in marine mammals, and the presence of this phenotype can induce deep alveolar collapse during diving, thereby reducing the risk of DCS during diving. Conclusions: The study unveils pivotal genetic signals in cetaceans and other marine mammals, arising through evolution. These genetic signals may influence lung characteristics in marine mammals and have been linked to a reduced risk of developing DCS. Moreover, the research serves as a valuable reference for delving deeper into human diving physiology. [ABSTRACT FROM AUTHOR]