RESUMEN
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.
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Enfermedad de Descompresión , Buceo , Foramen Oval Permeable , Humanos , Enfermedad de Descompresión/complicaciones , Enfermedad de Descompresión/diagnóstico por imagen , Buceo/efectos adversos , Foramen Oval Permeable/complicaciones , Foramen Oval Permeable/diagnóstico por imagen , Masculino , Adulto , Personal Militar , Tamizaje Masivo/métodos , Tamizaje Masivo/normasRESUMEN
The foramen ovale plays a vital role in sustaining life in-utero; however, a patent foramen ovale (PFO) after birth has been associated with pathologic sequelae in the systemic circulation including stroke/transient ischemic attack (TIA), migraine, high altitude pulmonary edema, decompression illness, platypnea-orthodeoxia syndrome (POS) and worsened severity of obstructive sleep apnea. Importantly, each of these conditions is most commonly observed among specific age groups: migraine in the 20 to 40s, stroke/TIA in the 30-50s and POS in patients >50 years of age. The common and central pathophysiologic mechanism in each of these conditions is PFO-mediated shunting of blood and its contents from the right to the left atrium. PFO-associated pathologies can therefore be divided into (1) paradoxical systemic embolization and (2) right to left shunting (RLS) of blood through the PFO. Missing in the extensive literature on these clinical syndromes are mechanistic explanations for the occurrence of RLS, including timing and the volume of blood shunted, the impact of age on RLS, and the specific anatomical pathway that blood takes from the venous system to the left atrium. Visualization of the flow pattern graphically illustrates the underlying RLS and provides a greater understanding of the critical flow dynamics that determine the frequency, volume, and pathway of flow. In the present review, we describe the important role of foramen ovale in in-utero physiology, flow visualization in patients with PFO, as well as contributing factors that work in concert with PFO to result in the diverse pathophysiological sequelae.
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Foramen Oval Permeable , Humanos , Foramen Oval Permeable/fisiopatología , Foramen Oval Permeable/complicaciones , Trastornos Migrañosos/fisiopatología , Trastornos Migrañosos/etiología , Ataque Isquémico Transitorio/fisiopatología , Ataque Isquémico Transitorio/etiología , Apnea Obstructiva del Sueño/fisiopatología , Apnea Obstructiva del Sueño/complicaciones , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/fisiopatología , Enfermedad de Descompresión/fisiopatología , Enfermedad de Descompresión/complicaciones , Edema Pulmonar/etiología , Edema Pulmonar/fisiopatología , Embolia Paradójica/fisiopatología , Embolia Paradójica/etiologíaRESUMEN
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.Breen ID, Stepanek J, Marks L, Yale K, Mesinkovska N, Swanson D. Clinical significance of mottling rashes in diving decompression sickness. Aerosp Med Hum Perform. 2024; 95(9):695-702.
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Enfermedad de Descompresión , Buceo , Enfermedad de Descompresión/fisiopatología , Humanos , Buceo/efectos adversos , Exantema/etiología , Exantema/fisiopatología , Embolia Paradójica/etiología , Embolia Paradójica/fisiopatología , Relevancia ClínicaRESUMEN
INTRODUCTION: Biomarker responses to intensive decompression indicate systemic proinflammatory responses and possible neurological stress. To further investigate responses, 12 additional brain and lung biomarkers were assayed.METHODS: A total of 15 healthy men (20 to 50 yr) undertook consecutive same-day ascents to 25,000 ft (7620 m), following denitrogenation, breathing 100% oxygen. Venous blood was sampled at baseline (T0), after the second ascent (T8), and next morning (T24). Soluble protein markers of brain and lung insult were analyzed by enzyme-linked immunosorbent assay with plasma microparticles quantified using flow cytometry.RESULTS: Levels of monocyte chemoattractant protein-1 and high mobility group box protein 1 were elevated at T8, by 36% and 16%, respectively, before returning to baseline. Levels of soluble receptor for advanced glycation end products fell by 8%, recovering by T24. Brain-derived neurotrophic factor rose by 80% over baseline at T24. Monocyte microparticle levels rose by factors of 3.7 at T8 and 2.7 at T24 due to early and late responses in different subjects. Other biomarkers were unaffected or not detected consistently.DISCUSSION: The elevated biomarkers at T8 suggest a neuroinflammatory response, with later elevation of brain-derived neurotrophic factor at T24 indicating an ongoing neurotrophic response and incomplete recovery. A substantial increase at T8 in the ratio of high mobility group box protein 1 to soluble receptor for advanced glycation end products suggests this axis may mediate the systemic inflammatory response to decompression. The mechanism of neuroinflammation is unclear but elevation of monocyte microparticles and monocyte chemoattractant protein-1 imply a key role for activated monocytes and/or macrophages.Connolly DM, Madden LA, Edwards VC, Lee VM. Brain and lung biomarker responses to hyperoxic hypobaric decompression. Aerosp Med Hum Perform. 2024; 95(9):667-674.
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Biomarcadores , Quimiocina CCL2 , Receptor para Productos Finales de Glicación Avanzada , Humanos , Masculino , Biomarcadores/sangre , Biomarcadores/metabolismo , Adulto , Persona de Mediana Edad , Quimiocina CCL2/sangre , Receptor para Productos Finales de Glicación Avanzada/sangre , Factor Neurotrófico Derivado del Encéfalo/sangre , Descompresión/métodos , Adulto Joven , Encéfalo/metabolismo , Pulmón , Enfermedad de Descompresión/sangre , Hiperoxia/sangreRESUMEN
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.
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Enfermedad de Descompresión , Hígado , Polimorfismo de Nucleótido Simple , Prealbúmina , Animales , Femenino , Masculino , Ratas , Enfermedad de Descompresión/genética , Enfermedad de Descompresión/metabolismo , Resistencia a la Enfermedad/genética , Hígado/metabolismo , Proyectos Piloto , Prealbúmina/genética , Prealbúmina/metabolismo , Ratas Wistar , ARN Mensajero/metabolismo , ARN Mensajero/genéticaRESUMEN
BACKGROUND: Saturation diving is a standard method of intervention for commercial diving during offshore operations. Current saturation procedures achieve a high level of safety with regards to decompression sickness but still put the divers under multiple stressors: 1) Environmental stress (long confinement, heat/cold, dense gases, high oxygen levels), 2) Work stress (muscular fatigue, psychological pressure, breathing equipment, etc.), 3) venous gas emboli associated with decompression, 4) Inflammation related to oxidative stress and microparticles. We present the results of a saturation divers monitoring campaign performed in the North Sea Danish sector, on the Tyra field, during 2022. The study was supported by TotalEnergies, the field operator, and performed by Boskalis Subsea Services, the diving contractor, onboard the diving support vessel Boka Atlantis. The objective was twofold: document the level of diving stress during saturation operations in the Danish sector, and compare the performances of two saturation procedures, the Boskalis and the NORSOK procedures. MATERIALS AND METHODS: Fourteen divers volunteered for the study. The monitoring package include weight and temperature measurements, psychomotor tests (objective evaluation) and questionnaires (subjective evaluation), Doppler bubble detection and bioimpedance. The results were presented in a radar diagram that provides a general view of the situation. RESULTS: The data were analysed along 3 dimensions: work and environmental, desaturation bubbles, oxidative stress and inflammation. The results showed little or no variations from the reference values. No bubbles were detected after excursion dives and the final decompression, except for two divers with a grade 1 after arriving at surface. No statistical difference could be found between the Boskalis and the NORSOK saturation procedures. CONCLUSIONS: At a depth of 40-50 msw corresponding to the Danish sector, the two saturation procedures monitored induce no or little stress to the divers. The divers know how to manage their diet, equilibrate their hydration and pace their effort. Data available on divers' post saturation period show a recovery over the 24-48 hours following the end of the decompression. Further research should focus on diving deeper than 100 msw where a greater stress can be anticipated.
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Enfermedad de Descompresión , Buceo , Humanos , Buceo/efectos adversos , Buceo/fisiología , Mar del Norte , Adulto , Masculino , Saturación de Oxígeno/fisiología , Persona de Mediana Edad , Estrés Fisiológico , Dinamarca , Monitoreo Fisiológico/métodosRESUMEN
Inner ear decompression sickness (IEDCS) is an uncommon diving-related injury affecting the vestibulocochlear system, with symptoms typically including vertigo, tinnitus, and hearing loss, either in isolation or combination. Classically associated with deep, mixed-gas diving, more recent case series have shown that IEDCS is indeed possible after seemingly innocuous recreational dives, and there has been one previous report of IEDCS following routine hyperbaric chamber operations. The presence of right-to-left shunt (RLS), dehydration, and increases in intrathoracic pressure have been identified as risk factors for IEDCS, and previous studies have shown a predominance of vestibular rather than cochlear symptoms, with a preference for lateralization to the right side. Most importantly, rapid identification and initiation of recompression treatment are critical to preventing long-term or permanent inner ear deficits. This case of a U.S. Navy (USN) diver with previously unidentified RLS reemphasizes the potential for IEDCS following uncomplicated diving and recompression chamber operations - only the second reported instance of the latter.
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Enfermedad de Descompresión , Buceo , Oxigenoterapia Hiperbárica , Enfermedad de Descompresión/etiología , Humanos , Buceo/efectos adversos , Masculino , Oído Interno/lesiones , Personal Militar , Adulto , Vértigo/etiología , Acúfeno/etiología , Cámaras de Exposición AtmosféricaRESUMEN
A 60-year-old man with hypertension and dyslipidemia complained of chest pain upon ascending from a maximum depth of 27 meters while diving. After reaching the shore, his chest pain persisted, and he called an ambulance. When a physician checked him on the doctor's helicopter, his electrocardiogram (ECG) was normal, and there were no bubbles in his inferior vena cava or heart on a portable ultrasound examination. The physician still suspected that he had acute coronary syndrome instead of decompression illness; therefore, he was transported to our hospital. After arrival at the hospital, standard cardiac echography showed a flap in the ascending aorta. Immediate enhanced computed tomography revealed Stanford type A aortic dissection. The patient obtained a survival outcome after emergency surgery. To our knowledge, this is the first reported case of aortic dissection potentially associated with scuba diving. It highlights the importance of considering aortic dissection in patients with sudden-onset chest pain during physical activity. In addition, this serves as a reminder that symptoms during scuba diving are not always related to decompression. This report also suggests the usefulness of on-site ultrasound for the differential diagnosis of decompression sickness from endogenous diseases that induce chest pain. Further clinical studies of this management approach are warranted.
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Disección Aórtica , Dolor en el Pecho , Enfermedad de Descompresión , Buceo , Humanos , Buceo/efectos adversos , Masculino , Persona de Mediana Edad , Disección Aórtica/etiología , Disección Aórtica/diagnóstico por imagen , Disección Aórtica/complicaciones , Disección Aórtica/cirugía , Dolor en el Pecho/etiología , Enfermedad de Descompresión/etiología , Enfermedad de Descompresión/terapia , Enfermedad de Descompresión/complicaciones , Enfermedad de Descompresión/diagnóstico por imagen , Enfermedad de Descompresión/diagnóstico , Enfermedad Aguda , Aneurisma de la Aorta/diagnóstico por imagen , Aneurisma de la Aorta/etiología , Aneurisma de la Aorta/complicaciones , Aneurisma de la Aorta/cirugía , Diagnóstico DiferencialRESUMEN
A widely accepted belief is that Nathaniel Henshaw was the first practitioner of hyperbaric medicine. He is said to have constructed the first hyperbaric chamber where he treated several disorders and provided opportunities to prevent disease and optimize well-being. While there is little doubt Henshaw was the first to conceptualize this unique medical technology, careful analysis of his treatise has convinced this writer that his was nothing more than a proposal. Henshaw's air chamber was never built. He would have failed to appreciate how its structural integrity could be maintained in the presence of enormous forces generated by envisioned changes in its internal pressure and, likewise, how its door could effectively seal the chamber during hypo-and hyperbaric use. Henshaw would have also failed to appreciate the limitations of his two proposed measuring devices and the toxic nature of one. Neither of these would have provided any quantitative information. The impracticality of his proposed method of compressing and decompressing the chamber is readily apparent. So, too, the likely toxic accumulation of carbon dioxide within the unventilated chamber during lengthy laborious periods required to operate it. Henshaw recommended pressures up to three times atmospheric pressure and durations for acute conditions until their resolution. Such exposures would likely result in fatal decompression sickness upon eventual chamber ascent, a condition of which nothing was known at the time. It would be another 170 years before a functional air chamber would finally become a reality. Henshaw's legacy, then, is limited to the concept of hyperbaric medicine rather than being its first practitioner.
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Oxigenoterapia Hiperbárica , Oxigenoterapia Hiperbárica/historia , Historia del Siglo XIX , Historia del Siglo XX , Cámaras de Exposición Atmosférica/historia , Enfermedad de Descompresión/terapia , Enfermedad de Descompresión/historiaRESUMEN
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.
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Enfermedad de Descompresión , Oxigenación por Membrana Extracorpórea , Paro Cardíaco , Humanos , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Anciano , Resultado Fatal , Paro Cardíaco/terapia , Paro Cardíaco/etiología , Enfermedad de Descompresión/terapiaRESUMEN
BACKGROUND: Accurate identification of vascular lumen region founded the base of bubble detection and bubble grading, which played a significant role in the detection of vascular gas emboli for the diagnosis of decompression sickness. OBJECTIVES: To assist in the detection of vascular bubbles, it is crucial to develop an automatic algorithm that could identify vascular lumen areas in ultrasound videos with the interference of bubble presence. METHODS: This article proposed an automated vascular lumen region recognition (VLRR) algorithm that could sketch the accurate boundary between vessel lumen and tissues from dynamic 2D ultrasound videos. It adopts 2D ultrasound videos of the lumen area as input and outputs the frames with circled vascular lumen boundary of the videos. Normalized cross-correlation method, distance transform technique, and region growing technique were adopted in this algorithm. Results A double-blind test was carried out to test the recognition accuracy of the algorithm on 180 samples in the images of 6 different grades of bubble videos, during which, intersection over union and pixel accuracy were adopted as evaluation metrics. The average IOU on the images of different bubble grades reached 0.76. The mean PA on 6 of the images of bubble grades reached 0.82. CONCLUSION: It is concluded that the proposed method could identify the vascular lumen with high accuracy, potentially applicable to assist clinicians in the measurement of the severity of vascular gas emboli in clinics.
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Algoritmos , Embolia Aérea , Humanos , Embolia Aérea/diagnóstico por imagen , Ultrasonografía/métodos , Enfermedad de Descompresión/diagnóstico por imagenRESUMEN
Introduction: Tasmania is a small island state off the southern edge of Australia where a comparatively high proportion of the 558,000 population partake in recreational or occupational diving. While diving is a relatively safe sport and occupation, Tasmania has a significantly higher diving death rate per head of population than other States in Australia (four times the national diving mortality rate). Methods: Three compressed gas diving deaths occurred in seven months between 2021-2022 prompting a review of the statewide approach for the immediate response of personnel to diving-related deaths. The review engaged first responders including the Police Marine and Rescue Service, hospital-based departments including the Department of Hyperbaric and Diving Medicine, and the mortuary and coroner's office. Results: An aide-mémoire for all craft groups, digitalised checklists for first responders (irrespective of diving knowledge), and a single-paged algorithm to highlight inter-agency communication pathways in the event of a diving death were designed to enhance current practices and collaboration. Conclusions: If used, these aids for managing diving related deaths should ensure that time-critical information is appropriately captured and stored to optimise information provided for the coronial investigation.
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Buceo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Algoritmos , Lista de Verificación , Enfermedad de Descompresión/mortalidad , Enfermedad de Descompresión/terapia , Buceo/estadística & datos numéricos , Socorristas/estadística & datos numéricos , Tasmania/epidemiologíaRESUMEN
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.
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Ejercicio Físico , Músculo Esquelético , Humanos , Masculino , Músculo Esquelético/fisiopatología , Ejercicio Físico/fisiología , Adulto , Adulto Joven , Altitud , Mialgia/fisiopatología , Descompresión/métodos , Fuerza Muscular/fisiología , Embolia Aérea/fisiopatología , Enfermedad de Descompresión/fisiopatologíaRESUMEN
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 shunt-mediated 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.
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Enfermedad de Descompresión , Defectos del Tabique Interatrial , Enfermedades Profesionales , Humanos , Enfermedad de Descompresión/etiología , Enfermedad de Descompresión/terapia , Masculino , Defectos del Tabique Interatrial/cirugía , Enfermedades Profesionales/etiología , Aire Comprimido/efectos adversos , Adulto , Oxigenoterapia Hiperbárica/métodos , Maniobra de Valsalva , Persona de Mediana Edad , Buceo/efectos adversosRESUMEN
Introduction: Inhalation of high concentrations of carbon dioxide (CO2) at atmospheric pressure can be toxic with dose-dependent 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.
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Dióxido de Carbono , Enfermedad de Descompresión , Animales , Humanos , Presión Atmosférica , Buceo/efectos adversos , Buceo/fisiologíaRESUMEN
ABSTRACT: Breath-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.
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Barotrauma , Contencion de la Respiración , Enfermedad de Descompresión , Buceo , Humanos , Buceo/lesiones , Buceo/efectos adversos , Barotrauma/etiología , Barotrauma/diagnóstico , Enfermedad de Descompresión/terapia , Enfermedad de Descompresión/etiología , Enfermedad de Descompresión/diagnóstico , Hipoxia/etiología , Narcosis por Gas Inerte/etiología , Narcosis por Gas Inerte/diagnósticoRESUMEN
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.
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Enfermedad de Descompresión , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Enfermedades Neuroinflamatorias , Animales , Enfermedad de Descompresión/fisiopatología , Enfermedad de Descompresión/metabolismo , Ratones , Masculino , Enfermedades Neuroinflamatorias/fisiopatología , Enfermedades Neuroinflamatorias/metabolismo , Micropartículas Derivadas de Células/metabolismo , Sistema Glinfático/fisiopatología , Sistema Glinfático/metabolismo , Corteza Cerebral/metabolismo , Corteza Cerebral/fisiopatología , Hipocampo/metabolismo , Hipocampo/fisiopatología , Inflamación/fisiopatología , Inflamación/metabolismo , Activación NeutrófilaRESUMEN
Decompression sickness (DCS) is caused by abrupt changes in extracorporeal pressure with varying severity. Symptoms range from mild musculoskeletal pain to severe organ dysfunction and death, especially among patients with chronic underlying disease. Here, we report an unusual case of a 49-year-old man who experienced DCS after a dive to a depth of 38 meters. The patient's symptoms progressed, starting with mild physical discomfort that progressed to disturbance of consciousness on the second morning. During hospitalization, we identified that in addition to DCS, he had also developed diabetic ketoacidosis, septic shock, and rhabdomyolysis. After carefully balancing the benefits and risks, we decided to provide supportive treatment to sustain vital signs, including ventilation support, sugar-reducing therapy, fluid replacement, and anti-infection medications. We then administered delayed hyperbaric oxygen (HBO2) when his condition was stable. Ultimately, the patient recovered without any sequelae. This is the first case report of a diver suffering from DCS followed by diabetic ketoacidosis and septic shock. We have learned that when DCS and other critical illnesses are highly suspected, it is essential to assess the condition comprehensively and focus on the principal contradiction.
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Enfermedad de Descompresión , Diabetes Mellitus , Cetoacidosis Diabética , Buceo , Choque Séptico , Masculino , Humanos , Persona de Mediana Edad , Cetoacidosis Diabética/complicaciones , Cetoacidosis Diabética/terapia , Enfermedad de Descompresión/complicaciones , Enfermedad de Descompresión/diagnóstico , Choque Séptico/complicaciones , Choque Séptico/terapia , Progresión de la EnfermedadRESUMEN
Introduction: This is a review of commercial heliox saturation decompression procedures. The scope does not include compression, storage depth or bell excursion dive procedures. The objectives are to: identify the sources of the procedures; trace their evolution; describe the current practice; and detect relevant trends. Methods: Eleven international commercial diving companies provided their diving manuals for review under a confidentiality agreement. Results: Modern commercial diving saturation procedures are derived from a small number of original procedures (United States Navy, Comex, and NORSOK). In the absence of relevant scientific studies since the late 80's, the companies have empirically adapted these procedures according to their needs and experience. Such adaptation has caused differences in decompression rates shallower than 60 msw, decompression rest stops and the decision to decompress linearly or stepwise. Nevertheless, the decompression procedures present a remarkable homogeneity in chamber PO2 and daily decompression rates when deeper than 60 msw. The companies have also developed common rules of good practice; no final decompression should start with an initial ascending excursion; a minimum hold is required before starting a final decompression after an excursion dive. Recommendation is made for the divers to exercise during decompression. Conclusions: We observed a trend towards harmonisation within the companies that enforce international procedures, and, between companies through cooperation inside the committees of the industry associations.
Asunto(s)
Enfermedad de Descompresión , Buceo , Humanos , Descompresión/efectos adversos , Oxígeno , Helio , Enfermedad de Descompresión/etiologíaRESUMEN
Introduction: Diving injuries are influenced by a multitude of factors. Literature analysing the full chain of events in diving accidents influencing the occurrence of diving injuries is limited. A previously published 'chain of events analysis' (CEA) framework consists of five steps that may sequentially lead to a diving fatality. This study applied four of these steps to predominately non-lethal diving injuries and aims to determine the causes of diving injuries sustained by divers treated by the Diving Medical Centre of the Royal Netherlands Navy. Methods: This retrospective cohort study was performed on diving injuries treated by the Diving Medical Centre between 1966 and 2023. Baseline characteristics and information pertinent to all four steps of the reduced CEA model were extracted and recorded in a database. Results: A total of 288 cases met the inclusion criteria. In 111 cases, all four steps of the CEA model could be applied. Predisposing factors were identified in 261 (90%) cases, triggers in 142 (49%), disabling agents in 195 (68%), and 228 (79%) contained a (possible-) disabling condition. The sustained diving injury led to a fatality in seven cases (2%). The most frequent predisposing factor was health conditions (58%). Exertion (19%), primary diver errors (18%), and faulty equipment (17%) were the most frequently identified triggers. The ascent was the most frequent disabling agent (52%). Conclusions: The CEA framework was found to be a valuable tool in this analysis. Health factors present before diving were identified as the most frequent predisposing factors. Arterial gas emboli were the most lethal injury mechanism.