Diving and hyperbaric medicine最新文献

Introduction: Necrotising soft tissue infections (NSTI) are serious infections associated with considerable morbidity and mortality. Heterogeneity of outcome reporting in the NSTI literature precludes the synthesis of high-quality evidence. There is substantial interest in studying the efficacy of hyperbaric oxygen treatment as an adjunctive treatment in NSTI. The aim of this study was to develop a set of core outcome measures for future trials evaluating interventions for NSTI.

Methods: A modified Delphi consensus method was used to conduct a three-round survey of a diverse panel of clinicians and researchers with expertise in NSTI, and patients with lived experience of NSTI. Participants rated the preliminary list of outcomes using a 9-point scale from 1 (least important) to 9 (most critical). The a priori definition of consensus required outcomes to be rated critical (score ≥ 7) by ≥ 70% of participants, and not important (score ≤ 3) by ≤ 15% of participants. After meeting consensus, outcomes were removed from subsequent rounds. Outcomes that did not meet consensus were included in subsequent rounds.

Results: Ninety-eight participants from 14 countries registered and 86%, 69% and 57% responded for each round, respectively. Outcome measures quantifying five core areas achieved consensus: Death, surgical procedures of debridements and amputations, functional outcome among survivors, measures of sepsis, including septic shock and organ dysfunction and resource use measured through length of hospital and intensive care unit stay.

Conclusions: This initial core set of outcome measures will be evaluated and optimised and can harmonise outcome measurements for investigations among patients with NSTI.

Introduction: Extreme deep technical diving presents significant physiological challenges. While procedures often blend elements from both recreational and commercial diving, many remain empirical and unvalidated for this purpose. The rise of closed-circuit rebreathers has reduced gas cost and logistical barriers, enabling more divers to reach unprecedented depths. This study, based on the experience of deep divers, explores the limits of extreme-depth diving and the strategies developed to overcome them.

Methods: Eight rebreather divers (one female, seven males) with experience beyond 200 metres depth were interviewed regarding their preparation, planning, and execution of such dives. The dive profiles of their deepest dives were analysed.

Results: All were highly experienced technical divers. The median maximal depth was 227 [209-302] metres, with a median total dive time of 290 [271-395] minutes. The gas density of the trimix mixture, oxygen exposure, and ascent rate consistently exceeded current recommendations. High pressure nervous syndrome did not appear to be a major limiting factor, whereas decompression posed greater challenges. Three divers experienced decompression sickness following their deepest dives, highlighting the uncertainty around decompression procedures.

Conclusions: These dives require rigorous preparation, robust support systems, equipment modifications, and perfect skills to reduce risks, which remain excessively high. Data are lacking to validate current practices. Decompression procedures must be adapted for these demanding mixed-gas dives, which are inevitably prolonged. A dry underwater habitat could improve decompression tolerance. The role of hydrogen as a breathing gas remains uncertain and still needs to be clarified, but some consider it a promising avenue for further exploration.

Pycnodysostosis is a rare lysosomal storage disorder characterised by short stature, craniofacial dysmorphisms, dental anomalies, and increased bone fragility due to osteoclast dysfunction caused by cathepsin K gene mutations. This case report describes a 43-year-old female pycnodysostosis patient with recurrent subtrochanteric fractures and delayed bone healing following multiple surgical interventions, including femoral osteotomy and bone grafting. Despite these efforts, bony union was not achieved. The patient underwent 39 sessions of hyperbaric oxygen therapy (HBOT), administered at 243.2 kPa for 120 minutes daily, five days per week. Post-treatment radiographs revealed significant fracture healing, with improvements continuing one month after therapy. Visual analogue pain scores decreased from 4 to 1, and quality of life (SF-36) improved. HBOT enhances tissue oxygenation, stimulating osteogenesis, neovascularization, and immune responses, while optimising osteoclast function, making it a promising treatment for pycnodysostosis-related fracture complications. Although ideal, a controlled trial of HBOT in this rare disorder is probably unachievable. Nevertheless, this report highlights HBOT as a potentially useful adjunctive treatment for enhancing healing of refractory fractures in pycnodysostosis patients.

This commentary discusses the provision of cardiopulmonary resuscitation to casualties in a diving bell. This single resource consolidates recent advances in the field, published in different medical journals, to support dissemination across the wider diving industry. It summarises the evaluation of techniques for the provision of manual cardiopulmonary resuscitation (CPR) to a seated casualty, including head-to-chest, knee-to-chest, and prone knee-to-chest compression delivery, and concludes that the only safe and potentially effective approach in a diving bell setting without room for a supine casualty is knee-to-chest CPR. The evaluation of a mechanical CPR device is discussed; it is found to be as effective as existing devices and manual CPR in terms of compression efficacy and is well-suited to the setting. The development of a bespoke resuscitation algorithm, together with deviations from accepted advanced life support algorithm principles, is presented. A novel 'upright CPR' technique for the provision of CPR to a seated casualty, developed during the algorithm evaluation process, is described. Finally, areas where evidence is still lacking, and research priorities for the future, are discussed; a key area for future work is the development and testing of a defibrillator suited to a diving bell setting, where space constraints, a heliox atmosphere, and the risk of both fire and rescuer injury are ever-present.

In December, we published an article titled "Dive Medicine Capability at Rothera Research Station (British Antarctic Survey), Adelaide Island, Antarctica" by Wood FNR, Bowen K, Hartley R, et al. The corresponding author would like to include an additional author, as their contribution was significant but was inadvertently omitted in the initial online publication. While this correction has been made in several versions circulated by the journal, not all have been updated. As a result, we are issuing an errata. The title and abstract are as follows: (Wood FNR, Bowen K, Hartley R, Stevenson J, Warner M, Watts D. Dive medicine capability at Rothera Research Station (British Antarctic Survey), Adelaide Island, Antarctica. Diving and Hyperbaric Medicine. 2024 20 December;54(4):320-327. doi: 10.28920/dhm54.4.320-327. PMID: 39675740.) Rothera is a British Antarctic Survey research station located on Adelaide Island adjacent to the Antarctic Peninsula. Diving is vital to support a long-standing marine science programme but poses challenges due to the extreme and remote environment in which it is undertaken. We summarise the diving undertaken and describe the medical measures in place to mitigate the risk to divers. These include pre-deployment training in the management of emergency presentations and assessing fitness to dive, an on-site hyperbaric chamber and communication links to contact experts in the United Kingdom for remote advice. The organisation also has experience of evacuating patients, should this be required. These measures, as well as the significant infrastructure and logistical efforts to support them, enable high standards of medical care to be maintained to divers undertaking research on this most remote continent.

Introduction: Hyperbaric oxygen therapy (HBOT) administers 100% oxygen in a pressurised chamber at pressures above 1 atmosphere absolute. Inside hyperbaric personnel accompany patients during sessions and breathe compressed air, exposing them to risks like decompression illness and respiratory changes. This study investigated whether hyperbaric exposure affects the long-term lung function of inside hyperbaric personnel.

Methods: An analysis was conducted on spirometry data from 14 personnel working between 2012 and 2023. Lung function tests measured forced vital capacity (FVC), forced expiratory volume in one second (FEV1), mid breath forced expiratory flow (FEF25-75), and peak expiratory flow (PEF) before and after hyperbaric exposure. Participants were categorised based on age, body mass index, number of HBOT sessions, and duration of employment.

Results: No clinically or statistically significant differences were found in FVC, FEV1, or PEF measurements before and after hyperbaric exposures (P > 0.05). However, FEF25-75, an indicator of small airway function, showed a (mean) 16% reduction in personnel with more than 150 HBOT sessions (P = 0.038). A post-hoc analysis confirmed a significant difference in FEF25-75 between personnel with fewer than 74 sessions and those with 150 or more sessions (P = 0.015). No clinically significant symptoms such as dyspnoea were reported during the study period.

Conclusions: The FEF25-75 reduction, without changes in FEV1, FVC, or PEF, could be due to improper performance of the FVC manoeuvre. Maintaining pulmonary health in inside hyperbaric personnel is essential, emphasising the importance of accurate FVC execution in assessments. Further studies are recommended to explore the long-term implications of these findings and the effects of repeated hyperbaric exposure on respiratory health.

We present the case of a 28-year-old female diver who performed a scuba air dive with significant omitted decompression obligation. She developed constitutional and neurological symptoms. Brain magnetic resonance imaging post treatment demonstrated multifocal embolic infarcts and transthoracic echocardiogram with bubble contrast on day three revealed a persistent foramen ovale (PFO) and severe right ventricular (RV) dilatation. We postulate that the high venous bubble load from the provocative decompression caused an increase in pulmonary artery pressure, leading to RV dilatation and increased right to left shunting of bubbles across her PFO, resulting in significant neurological deficits. This mechanism is analogous to that seen in acute thromboembolic pulmonary embolism.

Introduction: The aim was to examine the diving-related fatalities in Victoria, Australia from 2000 to 2022, identify trends and assess existing and potential countermeasures.

Methods: The National Coronial Information System and the Australasian Diving Safety Foundation (ADSF) database were searched to identify compressed gas diving and snorkelling/breath-hold diving deaths in Victoria for 2000-2022, inclusive. Data were extracted and analysed, and chain of events analyses conducted.

Results: Thirty-six scuba divers, one diver using surface supplied breathing apparatus (SSBA) and 25 snorkellers/breath-hold divers were identified. Compressed gas divers were older than snorkellers (medians 47 vs 36 years) with a higher proportion being overweight or obese (89% vs 61%), half with pre-existing medical conditions which likely contributed to their deaths. Most snorkellers died from primary drowning, often associated with inexperience. Half of all victims were inexperienced, and more than half of the accidents occurred while diving for seafood, often in rough conditions. Only one third of victims were with a buddy at the time of their accident. Of those known to be wearing weights, three-quarters were still wearing them when found.

Conclusions: Diving medical assessment in divers aged 45 years or older needs to be strengthened and obesity should trigger medical assessment in older divers. Other identified risks included seafood collection, diving in adverse conditions, ineffective or no buddy system, overweighting, poor buoyancy control and failure to ditch weights. Many are longstanding problems, so relevant messages are still not penetrating the community. Constant reinforcement through formal training, internet forums and targeted educational campaigns is required.