Diving and hyperbaric medicine最新文献

{"title":"Changes in lung ultrasound presentation induced by breath-hold diving in a simulated depth competition at Taiwan.","authors":"Ying-Jen Chi, Hsiu-Yung Pan, Po-Chun Chuang, Chi-Yung Cheng, Han-Yu Li, Meng-Huan Wu","doi":"10.28920/dhm56.1.13-20","DOIUrl":"10.28920/dhm56.1.13-20","url":null,"abstract":"<p><strong>Introduction: </strong>Acute respiratory symptoms after diving are common among competitive breath-hold divers. These symptoms, including shortness of breath, cough, haemoptysis, and chest discomfort, are often linked to immersion pulmonary oedema (IPO) or pulmonary barotrauma. This study aimed to evaluate the incidence, clinical presentation, and risk factors of IPO using portable ultrasound devices in a depth competition for breath-hold divers in Taiwan.</p><p><strong>Methods: </strong>This observational study was conducted during a competition around Liuqiu Island, Taiwan. Twenty-five breath-hold divers participated. Lung ultrasonography was performed pre- and post-diving, along with measurements of basic vital signs. Symptoms and diving history were recorded. The primary outcome measure was B-line score before and after diving.</p><p><strong>Results: </strong>Following the dive, 7/25 (28%) of divers reported acute respiratory symptoms, 10/25 (40%) showed ultrasound evidence of increased extravascular lung fluid, and 2/25 (8%) met the clinical criteria for IPO, presenting with both symptoms and hypoxaemia (SpO₂ ≤ 95%) alongside positive B-lines. B-line scores significantly increased from a median of 4 (range 1-4) to 7 (range 3-13) (P = 0.048). Male sex, higher body mass index, and elevated pre-dive systolic blood pressure were significantly associated with positive ultrasound findings. Among all factors, only diving depth remained statistically significant associated with increased post-dive B-line scores (regression coefficient = 0.046) (P = 0.007).</p><p><strong>Conclusions: </strong>The incidence of post-dive acute respiratory symptoms was 28%, and 8% of participants exhibited clinical features of IPO. Positive lung ultrasound findings were observed in 40% of divers, mostly asymptomatic. Maximum diving depth was significantly associated with increased post-dive B-line scores.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 1","pages":"13-20"},"PeriodicalIF":1.3,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13654611/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147510558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the use of full-face masks for ventilation in dive rescue.","authors":"Elizabeth A Blizzard, Andrew A Grandin, Dalelynn Sims","doi":"10.28920/dhm56.1.2-7","DOIUrl":"10.28920/dhm56.1.2-7","url":null,"abstract":"<p><strong>Introduction: </strong>Early oxygenation is essential in a non-breathing scuba accident victim, but the need to exclude water has thus far prevented underwater ventilation, causing significant delay. The full-face mask (FFM) is a potential solution, but its safety and feasibility in this context has not been established. This is a preliminary study into the utility of FFMs for underwater ventilation.</p><p><strong>Methods: </strong>The tidal volume and peak inspiratory pressure delivered by the OTS Guardian and Neptune III FFMs were measured using a RespiTrainer Advance Airway Management Trainer and an open circuit scuba system. Ventilations were tested with varying lengths of purge valve depression and degrees of tightness of the FFM. A tidal volume of 350-560 mL was considered ideal. Thresholds considered to be high risk were 700 mL for volutrauma and peak inspiratory pressure > 3.4 kPa for barotrauma.</p><p><strong>Results: </strong>In all trials, the delivered pressure remained well below the 3.4 kPa threshold. The delivered volume was consistently less than 700 mL in at least one trial condition per FFM, although this required the fastest possible release of the Guardian purge valve without maximal mask tightening. The Neptune remained below 700 ml regardless of technique but required a one second purge valve depression to deliver sufficient volume (> 350 mL).</p><p><strong>Conclusions: </strong>Recommendations need to be tailored to specific masks styles or brands. However, this form of ventilation could be feasible. Our findings are most directly applicable to ventilation at the surface. Further testing of these and other FFMs in simulation at depth will be necessary to evaluate the masks' use for ventilation. These results merit further investigation.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 1","pages":"2-7"},"PeriodicalIF":1.3,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13654607/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147510013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual rebreathers in practice: example experiences from the Wetmules and COBRA Divers.","authors":"Daniel Lee, Craig Challen, Gareth Lock","doi":"10.28920/dhm56.1.88-94","DOIUrl":"10.28920/dhm56.1.88-94","url":null,"abstract":"<p><p>Closed-circuit rebreathers have opened new frontiers in technical diving, but rebreathers are not invulnerable and therefore a 'bailout' gas supply is required. For extreme dives, open-circuit bailout is logistically impossible. This has led teams to adopt dual rebreather configurations, where a second rebreather serves as bailout. This article presents operational experiences from the Wetmules and COBRA Divers, who independently developed dual rebreather practices for extended range diving. The teams evolved contrasting approaches through extensive field testing. The Wetmules initially adopted partially integrated configurations, sharing components between rebreathers to reduce complexity for deep dives with straightforward access to dive sites. COBRA Divers used fully independent dual rebreathers, prioritising complete redundancy for remote locations with challenging logistics. Both developed techniques to ensure the operational status of the inactive rebreather including gas content variability, buoyancy control, and fault detection. Real-world experience validated theoretical benefits while revealing additional considerations. Both teams significantly reduced open-circuit bailout requirements, enabling extended penetrations and depths that were previously extremely difficult. Key operational insights included maintaining breathable gas mixtures in inactive loops, regular integrity checks, and managing variable buoyancy. The approach introduced new challenges: increased task loading, maintenance requirements, and novel failure modes specific to inactive rebreathers, showing that equipment redundancy does not automatically enhance safety. Dual rebreathers extend operational envelopes but introduce significant complexity. Benefits include eliminating gas switches during emergencies and maintaining optimal decompression profiles. However, inactive rebreathers remain vulnerable to undetected failures and demand higher operator proficiency. The contrasting approaches - integration versus full independence - reflect different operational priorities and mission parameters. This article contributes operational experience to support informed decision-making within the technical diving community.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 1","pages":"88-94"},"PeriodicalIF":1.3,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13654608/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147510634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cutaneous decompression sickness after an air dive with oxygen breathed during decompression in a commercial diver with a persistent foramen ovale.","authors":"Peter Wilmshurst, Timothy Griffiths, Nigel Stokes, Grant Heatlie","doi":"10.28920/dhm55.4.427-429","DOIUrl":"10.28920/dhm55.4.427-429","url":null,"abstract":"<p><p>A 43-year-old commercial diver had cutaneous decompression sickness after a dive to 17 metres of seawater for 160 minutes breathing air with transfer under pressure and oxygen breathed during decompression in a dry chamber. He had worked as a commercial diver for 16 years without previous problems. A bubble contrast transthoracic echocardiogram showed a large atrial right-to-left shunt. His persistent foramen ovale (PFO) was closed using a transcatheter technique and he has returned to commercial diving. As far as we are aware, shunt-mediated decompression sickness has not been reported previously after a shallow air dive with oxygen breathed during decompression. The findings in this diver adds to the observation of occurrence of three episodes of cutaneous decompression sickness after dry hyperbaric exposure breathing air and decompression whilst breathing oxygen in two individuals with atrial right-to-left shunts.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"427-429"},"PeriodicalIF":1.3,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092555/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperbaric oxygen therapy as salvage treatment for post-traumatic sudden sensorineural hearing loss: a case report.","authors":"Luís André Baptista, Joana Guincho, Mariana Donato, Pedro Araújo, Carla Espiney Amaro, Pedro Alberto Escada","doi":"10.28920/dhm55.4.423-426","DOIUrl":"10.28920/dhm55.4.423-426","url":null,"abstract":"<p><strong>Introduction: </strong>We report the first case of hyperbaric oxygen therapy used to treat sensorineural hearing loss in a child after head trauma.</p><p><strong>Case report: </strong>A 13-year-old boy with no relevant past medical history presented to the emergency department with tinnitus and hypoacusia following head trauma. An ear computed tomography scan showed a right longitudinal temporal fracture sparing the otic capsule, and the audiogram identified a moderate sensorineural hearing loss in the right ear involving frequencies between 2,000 and 8,000 Hz. He was treated with corticosteroids and betahistine for an acute audiovestibular loss with resolution of the vestibular symptoms. At three months post-trauma the sensorineural hearing loss persisted. The patient started treatment with hyperbaric oxygen therapy with complete resolution of the hearing loss after 11 sessions.</p><p><strong>Conclusions: </strong>This case identifies potential benefit from salvage hyperbaric oxygen therapy in the treatment of sudden sensorineural hearing loss of traumatic etiology.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"423-426"},"PeriodicalIF":1.3,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092550/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical flicker fusion frequency measurement through a chamber porthole.","authors":"Jochen D Schipke, Thomas Muth, Anne-Kathrin Brebeck, Sven Dreyer","doi":"10.28920/dhm55.4.419-422","DOIUrl":"10.28920/dhm55.4.419-422","url":null,"abstract":"<p><p>The critical flicker fusion frequency (cFFF) is a non-invasive measure of central nervous system function and cortical arousal, increasingly used in diving and hyperbaric medicine to assess the effects of breathing gases under pressure. This feasibility study aimed to evaluate whether cFFF can be reliably measured through the porthole of a hyperbaric chamber. Forty-five experienced male divers underwent cFFF testing at various pressures (101.3 kPa outside chamber, then 101.3, 608, 132, 101.3 kPa inside [1.0 bar outside then 1.0, 6.0, 1.3, 1.0 bar inside]) using a manually operated LED flicker-device while standing at a fixed distance from the chamber window. Results showed that cFFF values were higher inside the chamber at 101.3 kPa (1.0 bar) compared to outside (45.6 Hz vs. 40.2 Hz), decreased under hyperbaric conditions (608 kPa [6 bar], 43.5 Hz), and declined further during decompression (132 kPa [1.3 bar], 42.1 Hz; 101.3 kPa [1.0 bar], 43.5 Hz). These findings support previous observations of gas-induced central nervous system effects and highlight the sensitivity of cFFF to pressure-related neural changes. The successful external measurement protocol addresses challenges associated with observer narcosis and movement artifacts in underwater settings. While limited by the homogenous participant group and lack of confirmatory measures, this approach may still be a valuable tool for future research into the temporal dynamics of gas narcosis and cortical excitation.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"419-422"},"PeriodicalIF":1.3,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092534/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of fluid loss on the physiology of closed-circuit rebreather divers after 100- and 45-metre dives.","authors":"Laura Tuominen, Richard Lundell, Costantino Balestra, Tomi Wuorimaa, Lauri Koponen, Sofia Sokolowski, Anne Räisänen-Sokolowski","doi":"10.28920/dhm55.4.391-397","DOIUrl":"10.28920/dhm55.4.391-397","url":null,"abstract":"<p><strong>Introduction: </strong>Diving induced immersion diuresis predisposes divers to dehydration. Dehydration is considered a risk factor for decompression sickness (DCS) but there is very little evidence to prove it. Dehydration also potentially modifies venous gas emboli (VGE) formation and impairs endothelial function. The purpose of this study was to report the effects of fluid loss during a dive on the diver's physiology.</p><p><strong>Methods: </strong>Nine divers performed a 45 metre fresh water (mfw) and a 100 mfw dive with predetermined dive profiles. Body weight was measured before and after the dive. Post-dive detection of VGE was performed according to the extended Eftedal-Brubakk scale. We also measured haematocrit and flow mediated dilation before and after the 100 mfw dives.</p><p><strong>Results: </strong>After a 68-minute dive to 45 mfw, median weight loss was -1.1 kg, (IQR -1.2, -1.0; range -2.0, -0.6), P = 0.009 and VGE were detected in all divers. After a 170-minute dive to 100 mfw, median weight loss was -1.5 kg (IQR -1.8, -1.1; range -2.2, -0.8), P = 0.009 and VGE were detected in seven divers. Weight loss after the dive was statistically significant and there was a negative correlation between weight loss and bubbling after the 45 mfw dives. None of the divers suffered any symptoms of DCS.</p><p><strong>Conclusions: </strong>We found significant weight loss after both decompression dives but there were no clinical DCS symptoms in any of the divers. This study does not offer new evidence supporting the notion that dehydration increases decompression stress in divers.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"391-397"},"PeriodicalIF":1.3,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092538/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation and clinical use of the Maquet (Getinge) original series Rotaflow extracorporeal membrane oxygenation device in hyperbaric conditions: a technical report.","authors":"Theo Tsouras, Bridget Devaney, Zhiliang Caleb Lin, Christopher Covelli, Lloyd Roberts, Vinodh Bhagyalakshmi Nanjayya, Ian Millar","doi":"10.28920/dhm55.4.323-329","DOIUrl":"10.28920/dhm55.4.323-329","url":null,"abstract":"<p><strong>Introduction: </strong>Extracorporeal membrane oxygenation (ECMO) has not been previously used clinically in the modern hyperbaric chamber. We describe the modifications, validation and clinical performance of the Maquet (Getinge) original series Rotaflow (Rotaflow 1), Quadrox-i adult microporous membrane oxygenator and permanent life support (PLS) circuit under hyperbaric conditions.</p><p><strong>Methods: </strong>A Rotaflow 1 and Quadrox oxygenator underwent power supply modifications and rigorous safety testing in the hyperbaric environment using a PLS circuit primed with normal saline. Clinical validation was subsequently undertaken during a 'last resort' course of 13 hyperbaric oxygen treatment (HBOT) sessions for a patient suffering a life threatening vaso-invasive fungal infection requiring support with venovenous ECMO.</p><p><strong>Results: </strong>Preliminary testing and subsequent clinical application in the hyperbaric chamber demonstrated steady flow through the circuit based on pump revolutions per minute, with up to 180 mL (10%) variability demonstrated between the console display compared to the independent flow meter. No significant changes to flow variability were noted during pressurisation and decompression phases. Device temperature remained within safe limits. No bubbles were visually or sonographically detected. There were no performance or integrity issues detected through compression, maintenance and decompression phases. During clinical use, the patient remained stable and hyperoxygenation targets were achieved. Membrane oxygenator oxygen inflow set at up to 8 L·min-1 maintained CO2 clearance.</p><p><strong>Conclusions: </strong>After safety related modifications to the console's power supply, the Rotaflow 1 console, Quadrox oxygenator and PLS circuit performed satisfactorily up to 243 kPa during repeated clinical use.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"323-329"},"PeriodicalIF":1.1,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12831603/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Commentary on the article by Stevens G, Smart DR. The influence of wetsuit thickness (≥ 7 mm) on lung volumes in scuba divers.","authors":"Jacques Regnard, Olivier Castagna","doi":"10.28920/dhm55.4.436-437","DOIUrl":"10.28920/dhm55.4.436-437","url":null,"abstract":"","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"436-437"},"PeriodicalIF":1.3,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13092551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of in-water recompression for decompression illness after deep freediving: a case series.","authors":"Nicole Lin, Elaine Yu, Anna Lussier, Emmanuel Gouin, Peter Lindholm","doi":"10.28920/dhm55.4.376-383","DOIUrl":"10.28920/dhm55.4.376-383","url":null,"abstract":"<p><strong>Introduction: </strong>There are increasing anecdotal reports of in-water recompression in freedivers who surface with neurological symptoms, likely suffering from decompression illness (DCI). Given the remote locations where many cases occurred, divers often struggled to access medical care, including the gold-standard hyperbaric oxygen treatment (HBOT), thus resorting to in-water recompression (IWR). Currently, IWR guidelines have only been discussed for scuba and surface supplied divers in specific scenarios, with protocols prescribing oxygen breathing at depths ≤ 9 metres maximum for around 1-3 hours.</p><p><strong>Methods: </strong>We conducted detailed interviews with six competitive freedivers on signs, symptoms, management, and resolution of 13 cases of DCI. We additionally requested records of medical evaluation and treatment, with their consent.</p><p><strong>Results: </strong>Three cases were suggestive of decompression sickness, six were consistent with arterial gas embolism, and four were ambiguous. Six cases were treated with IWR for 20-90 min at 5-25 metres with partial to complete resolution of symptoms. Four of these cases received HBOT afterwards. One diver reported significant permanent disability. Divers made several regimen changes after these incidents, including staying well-hydrated, reducing lung-packing, slowing their ascent rate, and/or employing prophylactic IWR when diving beyond a specified depth.</p><p><strong>Conclusions: </strong>Given the remote locations of many incidents, freedivers often faced challenges in accessing HBOT. Self-treatment with IWR was widely used, either as a bridge to HBOT or as a standalone remedy. IWR poses potential risks, especially at the deeper depths reported in this study. This treatment modality is being utilised sometimes without medical oversight and recommended guidelines for IWR for freedivers should be developed.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"55 4","pages":"376-383"},"PeriodicalIF":1.1,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12831604/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145713750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}