PLEASE NOTE THIS ISSUE WILL BE PUBLISHED ON THE 20 DECEMBER 2025 AND AVAILABLE AFTER THAT DATE.

Full article available here.

Novel use of hyperbaric oxygen treatment for treatment-resistant disseminated Saksenaea and Fusarium in a patient on extracorporeal membrane oxygenation (ECMO): a case report

Bridget Devaney^1–3, Joseph Mathew^4,5, Scott Ferris^6,7, Lloyd Roberts^1,3, Christopher Covelli⁸, Judit Orosz^1,3, Vinodh Bhagyalakshmi Nanjayya^1,3,9, Andrew Fuller¹⁰, Ian Millar^1,3

¹ Department of Intensive Care and Hyperbaric Medicine, Alfred Health, Melbourne, Australia
² Emergency and Trauma Centre, Alfred Health, Melbourne, Australia
³ Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia
⁴ Trauma Service, Alfred Health, Melbourne, Australia
⁵ National Trauma Research Institute, School of Translational Medicine, Department of Surgery, Monash University, Melbourne, Australia
⁶ Plastic, Hand and Faciomaxillary Surgery, Alfred Health, Melbourne, Australia
⁷ Victorian Plastic Surgery Unit, St Vincents Private Hospital, East Melbourne, Australia
⁸ Monash University, Melbourne, Australia
⁹ Australian New Zealand Intensive Care Research Centre, Melbourne, Australia
¹⁰ Department of Infectious Diseases, Alfred Health, Melbourne, Australia

Corresponding author: Dr Bridget Devaney, Department of Intensive Care and Hyperbaric Medicine, Alfred Health, 55 Commercial Road, Melbourne, VIC 3004, Australia
ORCiD: 0000-0001-6521-418X
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Case reports; Infection; Mucormycosis; Vaso-invasive fungal disease; Trauma

Abstract

(Devaney B, Mathew J, Ferris S, Roberts L, Covelli C, Orosz J, Nanjayya VB, Fuller A, Millar I. Novel use of hyperbaric oxygen treatment for treatment-resistant disseminated Saksenaea and Fusarium in a patient on extracorporeal membrane oxygenation (ECMO): a case report. Diving and Hyperbaric Medicine. 2025 December 20;55(4):309−314. doi: 10.28920/dhm55.4.309-314. PMID: 41364853.)
Filamentous soil moulds such as Saksenaea and Fusarium are angioinvasive fungi responsible for severe disseminated infections. Saksenaea causes zygomycosis, with disseminated cases having over ninety percent mortality. Fusarium, a hyphomycetes mould, can also cause disseminated infections in immunocompromised individuals, with high mortality. We describe the case of a normally healthy 20-year-old male who survived major traumatic injuries resulting from an aviation incident. He subsequently developed disseminated cutaneous zygomycetes (Saksenaea) and Fusarium infection with associated immunosuppression, multiorgan dysfunction and sepsis. Treatment strategies included repeated and extensive surgical debridement (inferior orbital region to carotid sheath in the neck, to a depth of buccal mucosa and zygomatic bone in the cheek), antifungal agents including intravenous (IV) liposomal amphotericin B and voriconazole, and IV immunoglobulin and granulocyte colony stimulating factor. Despite maximal medical and surgical treatment, disease control was not achieved. After multi-specialty consensus that current management had failed to control the disease process, hyperbaric oxygen treatment (HBOT) was added to standard therapy on an experimental basis based on several case reports, pathophysiological rationale, and institutional experience with angioinvasive Mucor. The patient was on venovenous extracorporeal membrane oxygenation for all HBOT sessions; details are reported separately. Thirteen treatment sessions (243 kPa [2.4 atmospheres absolute], 95 min) were successfully delivered. Local and systemic disease control was achieved within several days of commencing HBOT, and after a prolonged period of rehabilitation and reconstruction, the patient was discharged home. We conclude that HBOT may have an important role in the management of angioinvasive fungal disease.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Full article available here.

The process, logistics and governance behind a high-stakes novel intervention: the use of extracorporeal membrane oxygenation (ECMO) in the hyperbaric chamber

Brandon Adams¹, Adele Templeton¹, Theo Tsouras¹, Jayne Sheldrake¹, Lloyd Roberts^1,2, Zhiliang Caleb Lin^1,2,3, Ian Millar^1,2, Judit Orosz^1,2, Tania Birthisel¹, Bridget Devaney^1,2,3

¹ Department of Intensive Care and Hyperbaric Medicine, Alfred Health, Melbourne, Australia
² Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Australia
³ Emergency and Trauma Centre, Alfred Health, Melbourne, Australia 

Corresponding author: Dr Bridget Devaney, Department of Intensive Care and Hyperbaric Medicine, Alfred Health, 55 Commercial Road, Melbourne, VIC 3004, Australia
ORCiD: 0000-0001-6521-418X
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Hyperbaric oxygen; Intensive care medicine; Perfusion; Risk assessment; Risk management; Workflow

Abstract
(Adams B, Templeton A, Tsouras T, Sheldrake J, Roberts L, Lin ZC, Millar I, Orosz J, Birthisel T, Devaney B. The process, logistics and governance behind a high-stakes novel intervention: the use of extracorporeal membrane oxygenation (ECMO) in the hyperbaric chamber. Diving and Hyperbaric Medicine. 2025 December 20;55(4):315−322. doi: 10.28920/dhm55.4.315-322. PMID: 41364854.)
Introduction: A multi-trauma patient receiving extracorporeal membrane oxygenation (ECMO) developed severe disseminated vaso-invasive fungal disease. In the absence of any remaining treatment escalation options, hyperbaric oxygen treatment (HBOT) was considered as a last effort at gaining disease control. Previously, the use of modern ECMO devices had not been validated for hyperbaric use at our centre or, to the best of our knowledge, at any other centre around the world. We had, however, identified a potentially hyperbaric compatible ECMO device and had commenced a validation process. The aim of this report is to highlight the practical, operational and governance processes undertaken to safely provide HBOT utilising ECMO at short notice.
Methods: A detailed risk assessment, development of risk reduction strategies and workflows, emergency out-of-session ethics review, clinical innovations committee review, legal advice, executive approvals and informed consent were undertaken over a 32-hour period prior to commencing HBOT.
Results: We present the identified risks, governance approvals, workflow, staffing model, chamber layout and safety checklist utilised to successfully deliver thirteen HBOT sessions to a patient on venovenous (VV) ECMO.
Conclusions: Through an extensive and coordinated effort involving multiple specialties and disciplines at our service, we were able to safely deliver HBOT to a patient supported by VV ECMO.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Full article available here.

Validation and clinical use of the Maquet (Getinge) original series Rotaflow extracorporeal membrane oxygenation device in hyperbaric conditions: a technical report

Theo Tsouras¹, Bridget Devaney^1,2,3, Zhiliang Caleb Lin^1,2,3, Christopher Covelli⁴, Lloyd Roberts^1,3, Vinodh Bhagyalakshmi Nanjayya^1,3, Ian Millar^1,3

¹ Department of Intensive Care and Hyperbaric Medicine, Alfred Health, Melbourne, Australia
² Emergency and Trauma Centre, Alfred Health, Melbourne, Australia
³ School of Public Health and Preventative Medicine, Monash University, Melbourne, Australia
⁴ Monash University, Melbourne, Australia

Corresponding author: Dr Bridget Devaney, Department of Intensive Care and Hyperbaric Medicine, Alfred Health, 55 Commercial Road, Melbourne, VIC 3004, Australia
ORCiD: 0000-0001-6521-418X
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
ECMO; Equipment; Hyperbaric oxygen treatment; Intensive care; Life support; Medical devices; Perfusion

Abstract
(Tsouras T, Devaney B, Lin ZC, Covelli C, Roberts L, Nanjayya VB, Millar I. Validation and clinical use of the Maquet (Getinge) original series Rotaflow extracorporeal membrane oxygenation device in hyperbaric conditions: a technical report. Diving and Hyperbaric Medicine. 2025 December 20;55(4):323−329. doi: 10.28920/dhm55.4.323-329. PMID: 41364855.)
Introduction: 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.
Methods: 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 veno-venous ECMO.
Results: 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.
Conclusions: 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.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Full article available here.

Functional outcome and quality of life after iatrogenic cerebral air embolism treated with hyperbaric oxygen: a prospective cohort study

Raoul A Fakkert^1,2,3*, Lisa van Beers^1,2,3,*, Nina C Weber³, Benedikt Preckel¹, Robert A van Hulst^1,2, Robert P Weenink^1,2

¹ Department of Anesthesiology, Amsterdam UMC, Amsterdam, The Netherlands
² Department of Hyperbaric medicine, Amsterdam UMC, Amsterdam, The Netherlands
³ Laboratory of Experimental Intensive Care and Anesthesiology, Amsterdam UMC, Amsterdam, The Netherlands
^* Dr Fakkert and Dr van Beers contributed equally to the manuscript

Corresponding author: Dr Robert P Weenink, Department of Anesthesiology, Amsterdam UMC, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
ORCiD: 0000-0003-3079-4115
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Arterial gas embolism; Health surveys; Hyperbaric medicine; Treatment sequelae

Abstract
(Fakkert RA, van Beers L, Weber NC, Preckel B, van Hulst RA, Weenink RP. Functional outcome and quality of life after iatrogenic cerebral air embolism treated with hyperbaric oxygen: a prospective cohort study. Diving and Hyperbaric Medicine. 2025 December 20;55(4):330−337. doi: 10.28920/dhm55.4.330-337. PMID: 41364856.)
Introduction: Iatrogenic cerebral air embolism (CAE) is an uncommon, potentially fatal condition characterised by accidental introduction of air into the circulation during invasive procedures. Prompt recognition and treatment with hyperbaric oxygen therapy (HBOT) are required. Data on long-term functional outcome and specifically quality of life (QoL) in patients experiencing CAE are limited.
Methods: This prospective, single-centre, observational cohort study examined patients with iatrogenic CAE who were treated with HBOT. Patient characteristics, clinical severity scores and treatment details were recorded. The primary outcomes of the study were the Glasgow Outcome Scale (GOS) score at discharge and six months, and QoL measured by the World Health Organization quality of life brief version at six months.
Results: A total of 22 patients were included, with 14 patients (64%) having arterial CAE, five (23%) retrograde venous CAE, and the remaining three having either both (n = 1) or unknown (n = 2) forms of CAE. Median time-to-HBOT was seven hours [IQR 5–10]. The overall mortality rate was 23% (n = 5), 8 of 22 patients achieving full recovery (GOS 5) at six months, and another six patients having moderate disability (GOS 4) at six months. Nine of 17 survivors (53%) reported a decline in QoL compared to their pre-incident status. Outcome in patients with retrograde venous CAE seemed to be better, and outcome in patients with CAE following neuroangiographic procedures for stroke or subarachnoid haemorrhage seemed to be worse, compared to the remainder of patients.
Conclusions: Iatrogenic CAE is associated with substantial morbidity and mortality, with only a third of patients in our cohort achieving good functional recovery. Over half of survivors in this cohort self-reported reduced QoL as compared to their situation before the CAE incident.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

The incidence of cardiac arrest requiring defibrillation and defibrillation protocols in Australasian hyperbaric units

Anja G Beilharz¹, Neil Banham¹, Ian Gawthrope¹

¹ Department of Hyperbaric Medicine, Fiona Stanley Hospital, Murdoch, Australia

Corresponding author: Dr Neil Banham, Department of Hyperbaric Medicine, Fiona Stanley Hospital, 11 Robin Warren Drive, Murdoch WA 6150, Australia
ORCID: 0000-0002-1737-5859
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Cardiovascular; Diving medicine; Fire or explosion; Hyperbaric medicine; Hyperbaric facilities; Pressure chambers; Safety

Abstract
(Beilharz AG, Banham N, Gawthrope I. The incidence of cardiac arrest requiring defibrillation and defibrillation protocols in Australasian hyperbaric units. Diving and Hyperbaric Medicine. 2025 December 20;55(4):338−342. doi: 10.28920/dhm55.4.338-342. PMID: 41364857.)
Introduction: Cardiac arrest (CA) during hyperbaric oxygen treatment (HBOT) is exceedingly rare with only a few cases reported. It is unknown if in-chamber defibrillation of a patient has been performed in Australasia. In-chamber defibrillation is potentially dangerous with the risk of fire in an oxygen-rich environment. Australasian Standards prohibit the use of currently available defibrillators licensed for in-chamber use, as they contain lithium batteries. This study aimed to investigate how CA is managed in Australasian hyperbaric medicine units (HMUs) and to establish if there is a need to develop standardised protocols.
Methods: A 10-part SurveyMonkey® questionnaire sent to all 15 Australasian HMUs. Questions aimed to ascertain if there were cases where defibrillation during HBOT was indicated and if it was performed. We asked about emergency treatment protocols, defibrillation capabilities and if regular training drills were conducted. We asked if colleagues felt the need to have a uniform treatment protocol across Australasia and invited them to share their emergency protocols.
Results: Fourteen responses (93.3%) were received. No clinical cases of in-chamber CA or defibrillation were reported. Examples of emergency treatment protocols were provided by two respondents. Six respondents (43%) stated that regular emergency training drills for CA are performed in their HMU. Eleven respondents (79%) favoured standardised treatment protocols; however, comments suggested that this might be unachievable.
Conclusions: CA requiring defibrillation in the hyperbaric medicine context is rare and has not been performed in Australasia. Most HMUs have protocols in place, but they are not universally practiced regularly.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Hyperbaric oxygen treatment and pulmonary air-containing lesions

Osman Türkmen1, Recep Özkan2, Kübra Özgök Kangal3, Merve Dur İnce4, Yakup Arslan5

¹ Department of Undersea and Hyperbaric Medicine, Samsun Training and Research Hospital, Samsun, Türkiye
² Department of Undersea and Hyperbaric Medicine, Van Training and Research Hospital, Van, Türkiye
³ Department of Undersea and Hyperbaric Medicine, Health Sciences University, Gülhane Training and Research Hospital, Ankara, Türkiye
⁴ Department of Radiology, Health Science University, Gülhane Training and Research Hospital, Ankara, Türkiye
⁵ Department of Pulmonology, Health Sciences University, Gülhane Training and Research Hospital, Ankara, Türkiye

Corresponding author: Dr Osman Türkmen, Department of Undersea and Hyperbaric Medicine, Samsun Training and Research Hospital, Kadıköy Neighborhood, Barış Boulevard, No:199, 55090 İlkadım/Samsun, Türkiye
ORCiD: 0000-0001-6819-4356
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Bullae; Lungs; Hyperbaric oxygen treatment; Pulmonary barotrauma

Abstract
(Türkmen O, Özkan R, Özgök Kangal K, Dur İnce M, ArslanY. Hyperbaric oxygen treatment and pulmonary air-containing lesions. Diving and Hyperbaric Medicine. 2025 December 20;55(4):343−351. doi: 10.28920/dhm55.4.343-351. PMID: 41364858.)
Introduction: Pulmonary barotrauma is a rare but serious complication of hyperbaric oxygen treatment. Pulmonary air-containing lesions may predispose pulmonary barotrauma by causing air trapping during changes in environmental pressure. This study aimed to investigate whether pulmonary air-containing lesions cause pulmonary barotrauma during hyperbaric oxygen treatment.
Methods: This study retrospectively analysed data from individuals who presented to the Undersea and Hyperbaric Medicine Clinic at Gülhane Training and Research Hospital, Health Sciences University, between 2017 and 2022. The relationship between presence of pulmonary air-containing lesions on computed tomography and pulmonary barotrauma was evaluated.
Results: Gas containing lesions were not associated with an increased risk of pulmonary barotrauma. The incidence of pneumothorax during hyperbaric oxygen was extremely low (0.0059% per session, 0.15% per patient).
Conclusions: Pulmonary air-containing lesions, including bullae, were not associated with an increased risk under standard hyperbaric oxygen treatment protocols. Routine chest computed tomogaphy screening is not warranted due to the low complication rate. Nevertheless, clinical evaluation and informed consent are essential, particularly for patients with underlying lung disease. Further studies are needed to improve risk assessment.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Quality of reporting in hyperbaric medicine clinical trials: a cross-sectional study

Yeonjung Yoo¹, Angélique Cléroux², Neal W Pollock^3,4, Sylvain Boet^1,5,6,7

¹ Ottawa Hospital Research Institute, Acute Care Research Program, Ottawa, ON, Canada
² Department of Medicine, University of Ottawa, Ottawa, ON, Canada
³ Hyperbaric Medicine Unit, CISSS Chaudière-Appalaches (CHAU-Hôtel-Dieu de Lévis), Lévis, QC, Canada
⁴ Department of Kinesiology, Université Laval, Quebec, QC, Canada
⁵ Department of Anesthesiology and Pain Medicine, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada
⁶ Subaquatic and Hyperbaric Medicine Unit (UMSH), Division of Emergency Medicine, Department of Acute Care Medicine, Geneva University Hospitals, Switzerland
⁷ Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine, Faculty of Medicine, University of Geneva, Switzerland

Corresponding author: Dr Sylvain Boet, Unité de médecine subaquatique et hyperbare, Service des urgences des Hôpitaux Universitaires de Genève, Rue Gabrielle Perret-Gentil 2, CH-1201 Genève, Switzerland
ORCiD: 0000-0002-1679-818X
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
CONSORT; EQUATOR; Evidence-based medicine; Hyperbaric oxygenation; Reporting quality; STROBE

Abstract
(Yoo Y, Cléroux A, Pollock NW, Boet S. Quality of reporting in hyperbaric medicine clinical trials: a cross-sectional study. Diving and Hyperbaric Medicine. 2025 December 20;55(4):352−368. doi: 10.28920/dhm55.4.352-368. PMID: 41364859.)
Introduction: Research in hyperbaric oxygen (HBO) medicine is growing, but the quality of HBO studies is variable. Low study quality may compromise evidence-based decision-making and clinical translation.
Methods: This cross-sectional study examined the adherence of 50 randomly selected HBO clinical trials (25 randomised controlled trials [RCTs] and 25 observational studies) to relevant core reporting guidelines: consolidated standards of reporting trials (CONSORT), non-pharmacologic treatments (NPT), and strengthening the reporting of observational studies in epidemiology (STROBE). Studies published in peer-reviewed journals between January 2018 and May 2023 and indexed on PubMed were analysed. Reporting quality was classified as ‘excellent’ (> 85% of guideline items adequately reported), ‘good’ (50–85%), or ‘poor’ (< 50%).
Results: The sample represented 29% of RCTs and 16% of observational studies for the timeframe assessed. No study was rated as ‘excellent’ for completeness, 28 (56%) were rated as ‘good’, and 22 (44%) as ‘poor’. In RCTs, only one study (4%) adequately reported protocol adherence and eight studies (32%) reported blinding procedures. The NPT checklist showed that key items, including care provider adherence (0 studies) and participant adherence (one study; 4%), were frequently not reported. For observational studies, basic design elements were adequately reported, but with significant gaps in bias management (nine studies; 36%) and missing data handling (13 studies; 52%). Only six studies (12%) mentioned the use of reporting guidelines.
Conclusions: Our results showed that quality of reporting of HBO studies is suboptimal. These findings highlight the need for increased awareness and implementation of reporting guidelines, as well as the potential development of HBO-specific guidelines.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Full article available here.

Perceptions of airway protection tools: an international survey on the use of mouthpiece retaining straps in closed-circuit rebreather diving

Emmanuel Gouin^1,2,3,*, Emmanuel Dugrenot^1,2,4,5,*, Rachel M Lance⁶, Thierry Michot⁷, Laura Marroni⁶, Frauke Tillmans^1,4 

¹ Divers Alert Network, Durham, NC, United States
² University Brest, Laboratory ORPHY, IBSAM, Brest, France
³ CHRU La Cavale Blanche. Anesthesiology, Perioperative and Intensive Care Units, Brest, France
⁴ Lampe Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, United States
⁵ Subaquatic Operational Research Team (ERRSO), Military Institute of Biomedical Research (IRBA), 83000 Toulon, France 
⁶ Divers Alert Network Europe (DAN Europe), Roseto, Italy
⁷ University Brest, Laboratory LABERS UR 3149, Brest, France
^* Drs Gouin and Dugrenot contributed equally to this work

Corresponding author: Dr Emmanuel Dugrenot, Divers Alert Network. 6 W Colony Place, Durham, NC, 27705, USA
ORCiD: 0000-0002-6863-7919
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Accidents; Drowning; Gas toxicity; Risk management; Safety; Technical diving

Abstract
(Gouin E, Dugrenot E, Lance RM, Michot T, Marroni L, Tillmans F. Perceptions of airway protection tools: an international survey on the use of mouthpiece retaining straps in closed-circuit rebreather diving. Diving and Hyperbaric Medicine. 2025 December 20;55(4):369−375. doi: 10.28920/dhm55.4.369-375. PMID: 41364860.)
Introduction: Rebreather diving carries a high fatality rate (estimated 1.8–3.8 deaths per 100,000 dives), yet its popularity is growing. Among 54 French military divers who lost consciousness underwater, none died when using a mouthpiece retaining strap (MRS) in a team diving setup. Despite this, MRS use remains limited among recreational divers for whom drowning is a major cause of death. This study assessed knowledge, perceptions, and training regarding MRS use within the rebreather diving community.
Methods: An international online survey targeting certified rebreather divers was disseminated via social media. The survey gathered demographic information, diving experience, MRS usage, and details on related training.
Results: A total of 563 responses were collected. Of these, 133 (23.6%) were instructors, and 210 (37.3%) had received MRS training. On a 0 to 100 scale, divers trained on MRS use rated MRS importance higher (median score: 74 [IQR 33–90]) than divers with no MRS training (median: 49 [IQR 16–67]). Barriers to MRS adoption included negative past experiences, poor training, misuse, and concerns about complications during bailout procedures.
Conclusions: While not widely adopted among recreational divers, the MRS is supported by strong safety data. Formal training significantly improves its perceived value and acceptance. Greater involvement from manufacturers, training agencies, and instructors is essential to promote education and encourage MRS adoption as a key safety measure in rebreather diving.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

Full article available here.

Use of in-water recompression for decompression illness after deep freediving: a case series

Nicole Lin¹, Elaine Yu², Anna Lussier², Emmanuel Gouin^3,4, Peter Lindholm^2,5

¹ Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University, School of Medicine, California, USA
² Department of Emergency Medicine, University of California San Diego, San Diego, USA
³ Univ Brest, Laboratory ORPHY EA 4324, Brest, France
⁴ Department of Anesthesiology and Intensive Care, Brest University Hospital, La Cavale Blanche, Brest, France
⁵ Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden

Corresponding author: Dr Nicole Lin, Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University, School of Medicine, California, USA
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Arterial gas embolism; Breath-hold diving; Decompression sickness; Hyperbaric chamber; Treatment

Abstract
(Lin N, Yu E, Lussier A, Gouin E, Lindholm P. Use of in-water recompression for decompression illness after deep freediving: a case series. Diving and Hyperbaric Medicine. 2025 December 20;55(4):376−383. doi: 10.28920/dhm55.4.376-383. PMID: 41364861.)
Introduction: 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.
Methods: 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.
Results: 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.
Conclusions: 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.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Decompression illness in breath-hold divers: insights from an online survey

Elaine Yu¹, Nicole Lin², Peter Lindholm^1,3

¹ Department of Emergency Medicine, University of California San Diego, San Diego, USA
² Division of Thoracic Surgery, Department of Cardiothoracic Surgery, Stanford University, School of Medicine, California, USA
³ Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden

Corresponding author: Dr Elaine Yu, Department of Emergency Medicine, University of California San Diego, San Diego, USA
ORCiD: 0000-0002-4900-4913
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Arterial gas embolism; Decompression sickness; Freediving; Hyperbaric oxygen treatment; In-water recompression

Abstract
(Yu E, Lin N, Lindholm P. Decompression illness in breath-hold divers: insights from an online survey. Diving and Hyperbaric Medicine. 2025 December 20;55(4):384−390. doi: 10.28920/dhm55.4.384-390. PMID: 41364862.)
Introduction: Breath-hold divers can surface with neurological symptoms consistent with nitrogen buildup in tissues or gas entry into the arterial circulation, collectively termed decompression illness (DCI). While DCI has historically been attributed to diving with compressed air, breath-hold divers have reported similar syndromes. The causes, diagnosis, and management of DCI in breath-hold divers is poorly understood.
Methods: We developed an online survey that queried breath-hold divers on the symptoms they experienced during decompression illness events and the medical management of each event.
Results: A total of 36 (31 M, 5 F) breath-hold divers filled out the survey. A majority identified as recreational freedivers, competitive freedivers, and/or spearfishers with an average age of 45 years and 18 years of breath-hold diving experience. Of those surveyed, 33 (92%) held a certification from an accredited training agency. A total of 18 (50%) reported experiencing DCI, with 21 DCI incidents reported by 13 individuals from 1999–2024. Sixteen (76%) of DCI incidents occurred during training, with an average depth of 83.4 m and average speed of 1.0 m∙s-1. Thirteen (62%) percent of DCI incidents occurred while diving to depths shallower than a previous personal best. The most common symptoms were weakness, numbness, slurred speech, and fatigue. The most common treatment modalities were surface oxygen, in-water recompression, and hyperbaric oxygen therapy. Sixteen (76%) percent of divers had partial or complete resolution of their symptoms. The top cited contributors to the DCI incidents were depth, short surface interval between dives, and pulmonary barotrauma.
Conclusions: Breath-hold divers can experience DCI even when diving within their limits. The most cited contributors to DCI were depth, short surface interval between dives, and pulmonary barotrauma. Most divers’ symptoms resolved after treatment with surface oxygen, in-water recompression, and/or hyperbaric oxygen therapy.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Effects of fluid loss on the physiology of closed-circuit rebreather divers after 100- and 45-metre dives

Laura Tuominen^1,2,3, Richard Lundell^2,3, Costantino Balestra^4,5,6, Tomi Wuorimaa³, Lauri Koponen³, Sofia Sokolowski², Anne Räisänen-Sokolowski^2,3,7

¹ Department of Emergency, Emergency Medical Services, Centre for Prehospital Emergency Care, Tampere, Finland
² Department of Pathology, Helsinki University Hospital, and Helsinki University, Helsinki, Finland
³ Centre for Military Medicine, Finnish Defence Forces, Helsinki, Finland 
⁴ Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant
(HE2B), Brussels, Belgium
⁵ Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (ULB), Brussels, Belgium
⁶ DAN Europe Research Division (Roseto-Brussels), Brussels, Belgium
⁷ DAN Europe Foundation Research Division (Roseto-Helsinki), Helsinki, Finland

Corresponding author: Dr Laura Tuominen, Department of Emergency, Emergency Medical Services, Centre for Prehospital Emergency Care, Tampere, Finland
ORCiD: 0000-0003-0826-4679
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Decompression sickness; Dehydration; Diving medicine; Risk management; Technical diving; Vascular gas emboli

Abstract
(Tuominen L, Lundell R, Balestra C, Wuorimaa T, Koponen L, Sokolowski S, Räisänen-Sokolowski A. Effects of fluid loss on the physiology of closed-circuit rebreather divers after 100- and 45-metre dives. Diving and Hyperbaric Medicine. 2025 December 20;55(4):391−397. doi: 10.28920/dhm55.4.391-397. PMID: 41364863.)
Introduction: 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.
Methods: 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. 
Results: 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.
Conclusions: 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.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Hyperbaric oxygen therapy for acute idiopathic sudden sensorineural hearing loss; a systematic review with meta-analysis

Annemarie Newth¹, Matthias Perleth², Susannah Sherlock³, Lorena Romero⁴, Michael H Bennett⁵

¹ Echuca Regional Hospital, Victoria, Australia
² Federal Joint Committee (G-BA), Berlin, Germany
³ Wesley Centre for Hyperbaric Medicine, Brisbane, Australia
⁴ Alfred Health, Melbourne, Australia
⁵ Department of Diving and Hyperbaric Medicine, Prince of Wales Hospital, Sydney, Australia

Corresponding author: Dr Annemarie Newth, Echuca Regional Hospital, Victoria, Australia
ORCiD: 0009-0004-5038-8944
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Deafness; Inner ear; Treatment; Review article

Abstract
(Newth A, Perleth M, Sherlock S, Romero L, Bennett MH. Hyperbaric oxygen therapy for acute idiopathic sudden sensorineural hearing loss; a systematic review with meta-analysis. Diving and Hyperbaric Medicine. 2025 December 20;55(4):398−406. doi: 10.28920/dhm55.4.398-406. PMID: 41364864.)
Introduction: Idiopathic sudden sensorineural hearing loss (ISSHL) is hearing loss of unknown cause with greater than 30 dB loss over 72 hours or less across three consecutive frequencies. Hyperbaric oxygen therapy (HBOT) is a widely accepted treatment for this condition. HBOT protocols and outcomes measured vary between studies.
Methods: To update a systematic review with meta-analysis of relevant randomised trials to both quantify and estimate the quality of evidence to support or refute the use of HBOT for ISSHL. We followed the Cochrane Handbook for Systematic Reviews of Interventions methodology. We conducted a focussed search of the following databases – AMED, BIOSIS Previews, CENTRAL, CINAHL, Embase, Emcare, Global Health, Medline, Scopus and Web of Science. There were no language or publication status restrictions. The updated search covered 1 April 2012 to 22 February 2023. A total of 148 papers were found with 24 randomised and pseudo-randomised studies identified of which seven contributed to the final analysis. Studies using usual treatment (steroids) plus HBOT or no treatment plus HBOT were included. The ROBB 2 tool for risk of bias and the GRADE tool for certainty of evidence were utilised.
Results: Data pooling was hampered by variation in reporting of changes in pure tone average across these studies. Pooled analysis from five studies suggested the chance of improvement following HBOT and steroids was greater than after steroids alone (RR 1.6, 95% CI 1.3 to 2.0). Pooled data from four trials suggested a greater mean improvement following HBOT (mean difference 15.6 dB, 95% CI 1.5–29.8).
Conclusions: There is moderate evidence that HBOT improves hearing when applied up to 30 days after the onset of ISSHL. HBOT in combination with steroids (oral or intra-tympanic) can be justified as a routine treatment. Future trials should address optimal dose and timing of HBOT and ensure outcomes enable pooling of data in future reviews, as well as addressing some measure of the functional significance of any improvement.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

‘Power under pressure’ – defibrillation during hyperbaric oxygen therapy: a scoping review

Sophia Nöhl^1,2, Christian Burisch^3,4, Daniel Gödde^5*, Timur Sellmann^2,6*

¹ Faculty of Health, Witten/Herdecke University, Witten, Germany
² Department of Anaesthesiology I, Witten/Herdecke University, Witten, Germany
³ State of North Rhine-Westphalia, Regional Government Düsseldorf, Düsseldorf, Germany
⁴ Department of Didactics and Education Research in the Health Sector, Faculty of Health, Witten/Herdecke University, Witten, Germany
⁵ Department of Pathology and Molecular Pathology, Helios University Hospital Wuppertal, Witten/Herdecke University, Witten, Germany
⁶ Department of Anaesthesiology and Intensive Care Medicine, Evangelisches Krankenhaus BETHESDA zu Duisburg, Duisburg, Germany
^* Both authors share last authorship

Corresponding author: Sophia Nöhl, Department of Anesthesiology and Intensive Care Medicine, Evangelisches Krankenhaus Bethesda zu Duisburg, Heerstr. 219, 47053 Duisburg, Germany
ORCiD: 0009-0008-7515-8300
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Cardiac arrest; Defibrillation; Hyperbaric oxygen treatment; Medical conditions and problems; Resuscitation; Review article; Risk assessment

Abstract
(Nöhl S, Burisch C, Gödde D, Sellmann T. ‘Power under pressure’ – defibrillation during hyperbaric oxygen therapy: a scoping review. Diving and Hyperbaric Medicine. 2025 December 20;55(4):407−418. doi: 10.28920/dhm55.4.407-418. PMID: 41364865.)
Introduction: Although defibrillation is the standard treatment for cardiac arrest with shockable rhythms, its safety during hyperbaric oxygen therapy (HBOT) remains uncertain, as the oxygen-enriched atmosphere and increased ambient pressure could, in case of sparking, increase fire and explosion risk. As established guidelines are lacking, this scoping review synthesizes the current knowledge, addressing the unique challenges that arise in this special environment.
Methods: A systematic literature search was conducted in CINAHL, Cochrane Library, EMBASE and PubMed. Two authors independently screened titles and abstracts, with a third author resolving discrepancies. Duplicate records were removed after initial screening. Full-text screening was also performed independently by two authors. Manual data extraction focused on actual defibrillation during HBOT, including outcomes, safety concerns, recommendations and further helpful information. 
Results: The search initially identified 10,348 publications, ten of which were included. Screening of reference lists yielded another 23 publications, resulting in 33 finally included publications. Of these, four publications presented five patient cases of actual defibrillation during HBOT, while the remaining publications provided additional information on the topic. 
Conclusions: Findings highlight a lack of standardised guidelines and limited empirical data, necessitating cautious consideration of defibrillation during HBOT. Safety protocols, including oxygen level and equipment specifications, vary between monoplace and multiplace hyperbaric chambers, influencing the feasibility of in-chamber defibrillation. There is strong consensus that defibrillation is strictly contraindicated inside monoplace chambers, while in multiplace chambers, risks and benefits must be assessed individually. While defibrillation during HBOT is rare, ensuring its safety remains of paramount importance. Future research should focus on refining safety protocols and establishing guidelines to optimise patient outcomes during HBOT-associated emergencies.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Critical flicker fusion frequency measurement through a chamber porthole 

Jochen D Schipke¹, Thomas Muth², Anne-Kathrin Brebeck³, Sven Dreyer⁴

¹ Research Group Experimental Surgery, University Hospital Düsseldorf, Germany
² Institute of Occupational, Social, Environmental Medicine, Faculty of Medicine, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
³ Artemis Augenkliniken, Frankfurt am Main, Germany
⁴ Hyperbaric Oxygen Therapy, University Hospital Düsseldorf, Düsseldorf, Germany

Corresponding author: Professor Jochen Schipke, Research Group Experimental Surgery, University Hospital Düsseldorf, Germany
ORCID: 0000-0002-1747-5657
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Diving research; Narcosis; Hyperbaric research

Abstract

(Schipke JD, Muth T, Brebeck AK, Dreyer S. Critical flicker fusion frequency measurement through a chamber porthole. Diving and Hyperbaric Medicine. 2025 December 20;55(4):419−422. doi: 10.28920/dhm55.4.419-422. PMID: 41364866.)
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.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Hyperbaric oxygen therapy as salvage treatment for post-traumatic sudden sensorineural hearing loss: a case report

Luís André Baptista¹, Joana Guincho¹, Mariana Donato¹, Pedro Araújo², Carla Espiney Amaro³, Pedro Alberto Escada¹

¹ Serviço de Otorrinolaringologia do Hospital de Egas Moniz, Unidade Local de Saúde de Lisboa Ocidental, Lisbon, Portugal
² Serviço de Otorrinolaringologia do Hospital da Luz de Lisboa, Lisbon, Portugal
³ Centro de Medicina Subaquática e Hiperbárica de Lisboa, Lisbon, Portugal

Corresponding author: Dr Luís André Baptista, Serviço de Otorrinolaringologia do Hospital de Egas Moniz, Unidade Local de Saúde de Lisboa Ocidental, Lisbon, Portugal
ORCiD: 0009-0008-3475-0308
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Deafness; Hyperbaric medicine; Temporal bone fracture; Trauma

Abstract
(Baptista LA, Guincho J, Donato M, Araújo P, Amaro CE, Escada PA. Hyperbaric oxygen therapy as salvage treatment for post-traumatic sudden sensorineural hearing loss: a case report. Diving and Hyperbaric Medicine. 2025 December 20;55(4):423−426. doi: 10.28920/dhm55.4.423-426. PMID: 41364867.)
Introduction: We report the first case of hyperbaric oxygen therapy used to treat sensorineural hearing loss in a child after head trauma.
Case report: 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.
Conclusions: This case identifies potential benefit from salvage hyperbaric oxygen therapy in the treatment of sudden sensorineural hearing loss of traumatic etiology.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Cutaneous decompression sickness after an air dive with oxygen breathed during decompression in a commercial diver with a persistent foramen ovale

Peter Wilmshurst¹, Timothy Griffiths², Nigel Stokes², Grant Heatlie²

¹ United Kingdom Diving Medical Committee, UK
² University Hospitals of North Midlands, Newcastle Road, Stoke-on-Trent, UK

Corresponding author: Dr Peter Wilmshurst, United Kingdom Diving Medical Committee, UK
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Bubbles; Echocardiography; Occupational diving; Oxygen decompression; PFO; Transfer under pressure

Abstract

(Wilmshurst P, Griffiths T, Stokes N, Heatlie G. Cutaneous decompression sickness after an air dive with oxygen breathed during decompression in a commercial diver with a persistent foramen ovale. Diving and Hyperbaric Medicine. 2025  December 20;55(4):427−429. doi: 10.28920/dhm55.4.427-429. PMID: 41364868.)
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.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Hyperbaric oxygen therapy for hypoglycaemic encephalopathy due to insulinoma: a case report

Haitao Chu¹, Xiuchun Zhang², Hang Zhao¹, Xin Meng¹, Danna Wang¹, Yang Wang¹

¹ Department of Hyperbaric Oxygen Medicine, The First Hospital of China Medical University, Shenyang, China
² Department of Neurology, The First Hospital of China Medical University, Shenyang, China

Corresponding authors: Drs Danna Wang and Yang Wang, Department of Hyperbaric Oxygen Medicine, The First Hospital of China Medical University, No.155 Nanjing Bei Street, Heping District, Shenyang, China
This email address is being protected from spambots. You need JavaScript enabled to view it. (Dr D Wang)
This email address is being protected from spambots. You need JavaScript enabled to view it. (Dr Y Wang)

Keywords
Brain injury; Blood sugar level; Hyperbaric medicine; Hypoglycemia; Outcome

Abstract
(Chu H, Zhang X, Zhao H, Meng X, Wang D, Wang Y. Hyperbaric oxygen therapy for hypoglycaemic encephalopathy due to insulinoma: a case report. Diving and Hyperbaric Medicine. 2025 December 20;55(4):430−433. doi: 10.28920/dhm55.4.430-433. PMID: 41364869.)
Introduction: Hypoglycaemic encephalopathy is a potentially life-threatening condition which can present with seizures, altered mental status or focal neurologic deficits. Therapeutic options are limited and the overall prognosis is poor. Among previously reported cases, the maximum time for patients to recover consciousness after hypoglycaemic encephalopathy was 14 days. So far, no studies have reported that hyperbaric oxygen therapy (HBOT) can improve the consciousness disorder of hypoglycaemic encephalopathy.
Case report: We report a case of hypoglycaemic encephalopathy caused by insulinoma who had a refractory consciousness disorder for 90 days and whose recovery was temporally related to institution of HBOT, suggesting that HBOT is a possible treatment for hypoglycaemic encephalopathy.
Conclusions: Hyperbaric oxygen therapy can be considered in hypoglycaemic encephalopathy when the hypoglycaemia has been corrected but patients still have reduced consciousness.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Blurred vision after diving, what’s your diagnosis?

Jean-Eric Blatteau¹, Romain Roffi¹, Bernard Valero²

¹ HIA Sainte-Anne, Service de médecine hyperbare et d’expertise plongée (SMHEP), Toulon, France
² Hôpital d’Instruction des Armées Sainte-Anne France, Provence-Alpes-Côte d’Azur, Toulon, France

Corresponding author: Professor Jean-Eric Blatteau, HIA Sainte-Anne, Service de médecine hyperbare et d’expertise plongée (SMHEP), Toulon, France
ORCiD: 0000-0002-0961-1962
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Blindness, sudden; Decompression illness; Keratitis; Ophthalmology; Scuba diving

doi: 10.28920/dhm55.4.434-435. PMID: 41364870.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

The full article is currently under embargo for 12 months and will be made available on our website and PMC after this period. If you would like to access the article before it becomes publicly available, you can purchase it for personal use directly on our website. Alternatively, you may join SPUMS or EUBS to gain access to the entire issue.

Letter to the Editor - Commentary on the article by Stevens G, Smart DR. The influence of wetsuit thickness (≥ 7 mm) on lung volumes in scuba divers

Jacques Regnard¹, Olivier Castagna²

¹ Université Marie et Louis Pasteur, Physiology University Hospitals of Besançon, Bourgogne-Franche-Comté, France
² Hôpital d’Instruction des Armées Sainte-Anne France, Provence-Alpes-Côte d’Azur, Toulon, France

Corresponding author: Dr Jacques Regnard, Université Marie et Louis Pasteur, Physiology University Hospitals of Besançon, Bourgogne-Franche-Comté, France
This email address is being protected from spambots. You need JavaScript enabled to view it.

Keywords
Equipment; Immersion; Physiology; Respiratory

doi: 10.28920/dhm55.4.436-437. PMID: 41364871.

Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.