Diving and hyperbaric medicine最新文献

{"title":"The effect of hyperoxic environment on lung function and myopisation in an extended closed-circuit rebreather diving expedition.","authors":"Sofia A Sokolowski-Wojnicki, Mikolaj J Wojnicki, Anne K Räisänen-Sokolowski","doi":"10.28920/dhm56.3.294-302","DOIUrl":"10.28920/dhm56.3.294-302","url":null,"abstract":"<p><strong>Introduction: </strong>Repetitive closed-circuit rebreather (CCR) dives subject the human body to a hyperoxic environment. Prolonged oxygen exposure can lead to lung abnormalities and myopic shift. The aim of this study was to analyse the effects of a 31-day period of repeated CCR dives on divers' lung function and visual acuity.</p><p><strong>Methods: </strong>The CCR divers recruited for the study were participating in a research project in Chuuk Lagoon, Micronesia. Weekly measurements included lung function using spirometry and visual acuity with a Snellen chart. Oxygen exposure was calculated using multiple models. The impact on spirometry was tested by comparing the values before and after the expedition and by running regression analysis against accumulated oxygen exposure.</p><p><strong>Results: </strong>The divers (n = 12) performed a total of 173 CCR dives with mean (SD) maximum depth of 38 (13.9) msw and dive time 101 (38.8) min. The daily oxygen exposure limits for unit pulmonary toxic dose and central nervous system toxicity were respected. One diver had a decrease in multiple lung function parameters. Another developed spirometric evidence of mild obstruction by the end of the expedition. However, there were no statistically significant changes in spirometry results. Visual acuity showed fluctuations throughout the expedition, but no overall trend.</p><p><strong>Conclusions: </strong>Diving expeditions can be executed safely when respecting the guidelines for oxygen exposure. Reasonable oxygen exposure does not seem to significantly affect lung function or visual acuity.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 3","pages":"294-302"},"PeriodicalIF":1.3,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13645908/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148976089","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":"Evaluation of external ventricular drain performance under hyperbaric conditions: a bench study.","authors":"Rahulkumar Ramchandani, Zhiliang C Lin, Bridget Devaney, Rosalind L Jeffree, Theo Tsouras","doi":"10.28920/dhm56.3.323-328","DOIUrl":"10.28920/dhm56.3.323-328","url":null,"abstract":"<p><strong>Introduction: </strong>External ventricular drains (EVDs) are widely used for intracranial pressure (ICP) monitoring and cerebrospinal fluid (CSF) diversion in neurocritical care. Hyperbaric oxygen treatment (HBOT) exposes medical devices to increased ambient pressure; however, limited data exists regarding EVD performance and reliability under hyperbaric conditions.</p><p><strong>Methods: </strong>A bench study was conducted to evaluate EVD performance under hyperbaric conditions. A rigid, non-compressible saline-filled column was used to assess pressure measurement stability independent of compliance effects. Additional compliance-based syringe models were explored to assess the feasibility of evaluating unclamped drainage behaviour. A commercially available EVD system (CODMAN EDS 3; Codman and Shurtleff, a Johnson and Johnson company, Raynham, MA, USA) was exposed to stepwise ambient pressures from 101 to 283 kPa (1.0-2.8 atmospheres absolute) in a multiplace hyperbaric chamber. Pressure measurements, drainage behaviour, fluid column stability, and system integrity were assessed.</p><p><strong>Results: </strong>The CODMAN EDS 3 EVD system maintained structural integrity across tested pressure levels. While pressure measurements were stable in the rigid open glass syringe model, the closed compliance-based models demonstrated pressure variability during chamber pressurisation, including when closed to fluid drainage. Unclamped testing using these models demonstrated inconsistent fluid dynamics, precluding reliable assessment of fluid drainage behaviour under hyperbaric conditions.</p><p><strong>Conclusions: </strong>The CODMAN EDS 3 EVD system remained structurally intact during hyperbaric exposure; however, pressure measurements varied in closed models, including when closed to fluid drainage. ICP measurements obtained during HBOT should be interpreted with caution due to potential pressure-related artefacts. Reliable continuous assessment of fluid pressure drainage behaviour remains limited by current bench model constraints. Further research incorporating advanced brain compliance simulation models and carefully designed in-vivo observational studies is required to better characterise EVD behaviour under hyperbaric conditions and to ensure safe clinical use and accurate interpretation of ICP measurements in the hyperbaric environment.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 3","pages":"323-328"},"PeriodicalIF":1.3,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13645910/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148975870","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":"Occupational health challenges in commercial diving: a qualitative study of psychological risk, training gaps, and organisational responsibilities.","authors":"Holly Blake, Basharat Hussain, Lianne Hufton, Elisha Cousins, Graham Johnson, Andrew Tabner","doi":"10.28920/dhm56.3.226-236","DOIUrl":"10.28920/dhm56.3.226-236","url":null,"abstract":"<p><strong>Introduction: </strong>Little is known about the occupational health needs of commercial divers, particularly regarding psychological wellbeing, trauma exposure, organisational support, and the adequacy of training for high‑risk environments. This study qualitatively explored pathways into commercial diving, experiences of psychological strain and trauma, perceptions of support, and the relevance of training from the perspectives of divers, supervisors, and industry representatives.</p><p><strong>Methods: </strong>This qualitative study used semi‑structured interviews and focus groups with purposively sampled participants (n = 20 men). Data were analysed using reflexive thematic analysis.</p><p><strong>Results: </strong>Three themes were identified: (1) pathways into a high‑risk occupation shaped by financial incentives, risk acceptance, and informal entry routes; (2) psychological strain characterised by reported exposure to traumatic events, normalisation of distress, stigma surrounding mental health disclosure, and predominantly reactive organisational support; and (3) perceived inadequacies in training, described as generic, low‑fidelity, and insufficiently aligned with the operational realities of offshore and saturation diving, alongside limited opportunities to practise key skills, contributing to feelings of unpreparedness during emergencies.</p><p><strong>Conclusions: </strong>Participants described commercial diving as associated with substantial and often unaddressed psychological burden, compounded by cultural stigma, structural barriers to help‑seeking, and predominantly reactive support systems. Training provision was perceived as outdated and insufficiently aligned with operational demands, with limited organisational investment in development. Findings suggest that industry‑wide efforts may be needed to implement proactive mental‑health strategies and improve the alignment of training with operational realities.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 3","pages":""},"PeriodicalIF":1.3,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13645909/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148976076","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":"Measuring whole-body inert gas uptake and washout during submersion.","authors":"Oscar Plogmark, Kristian Soltesz, Carl Hjelte, Oskar Frånberg","doi":"10.28920/dhm56.3.388","DOIUrl":"10.28920/dhm56.3.388","url":null,"abstract":"<p><p>An error was identified in Figure 3 of the published article. The images in the figure were incorrectly placed, resulting in the same image being shown for each part of the figure. The online version of the article has been corrected, and the corrected figure will also be included in the version deposited in PubMed Central. However, three versions of the article had already been distributed before the error was identified and cannot be corrected retrospectively. The error is limited to Figure 3 and does not affect the text, data, results or conclusions of the article. The journal apologises for the error.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 3","pages":"388"},"PeriodicalIF":1.3,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13649588/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148976119","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":"Effect of a prior hypercapnia experience on recognition of hypercapnia in divers: a randomised controlled study.","authors":"Thalia Babbage, Hanna van Waart, Charlotte Jw Connell, Nicholas Gant, Simon J Mitchell, Xavier Ce Vrijdag","doi":"10.28920/dhm56.2.115-124","DOIUrl":"10.28920/dhm56.2.115-124","url":null,"abstract":"<p><strong>Introduction: </strong>Rebreather diving carries an increased risk of hypercapnia. Hypercapnia can cause impaired cognition, breathlessness, and increase the risk of oxygen toxicity. We investigated whether a prior unblinded hypercapnia experience, compared to reading about hypercapnia symptoms, would improve divers' ability to recognise hypercapnia and initiate self-rescue.</p><p><strong>Methods: </strong>Forty divers were recruited and randomised to receive either an unblinded hypercapnia experience (partial pressure of end-tidal carbon dioxide [P_ETCO₂] of 8.5 kPa) or an information leaflet explaining hypercapnia symptoms. At least one month later, participants in each group were further randomised to undergo blinded exposure to hypercapnia or normocapnia, allocated at 3:1. The primary outcome was the proportion of participants who self-initiated bailout prior to reaching P_ETCO₂ 8.5 kPa. Continuous cardiorespiratory data (P_ETCO₂ and P_ETO₂, tidal volume, respiratory rate, minute ventilation, heart rate, and blood pressure) were also recorded. Subjective symptoms associated with hypercapnia were assessed with a visual analogue scale.</p><p><strong>Results: </strong>Thirteen of 15 participants (87%) who received the unblinded hypercapnia-experience self-initiated bailout compared to 10/15 information leaflet participants (67%) (P = 0.149). There was no difference in cardiorespiratory physiology parameters at bailout between the groups. Shortness of breath, light-headedness, and disorientation were the most intensely reported symptoms. Approximately half (47%) of participants who received a hypercapnia training experience had a correlated symptom response during their subsequent hypercapnia testing session.</p><p><strong>Conclusions: </strong>Although no significant training benefit was shown, becoming familiar with the sensations associated with hypercapnia under appropriate supervision could be useful to rebreather divers both recreationally and within occupational settings.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 2","pages":"115-124"},"PeriodicalIF":1.3,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13374577/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249625","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":"Technical diving accidents in France: a 15-year retrospective study reporting a high prevalence of musculoskeletal decompression sickness.","authors":"Emmanuel Gouin, Anaïs Caillard, Colin Veses, Marc Luciani, Charlotte Lecomte, Emmanuel Dugrenot, François Guerrero, Jean-Éric Blatteau","doi":"10.28920/dhm56.2.125-136","DOIUrl":"10.28920/dhm56.2.125-136","url":null,"abstract":"<p><strong>Introduction: </strong>Technical diving, involving rebreathers and/or helium-based gas mixtures for deeper and longer dives, may influence risk and clinical presentation of injuries due to helium's properties, equipment constraints, or exposure conditions. This study aims to describe the specific characteristics of this accidentology.</p><p><strong>Methods: </strong>A retrospective study was conducted across five French coastline hyperbaric units. Medical records of technical divers presenting with decompression sickness (DCS), immersion pulmonary oedema (IPO), or gas-toxicity between 2010 and 2024 were reviewed.</p><p><strong>Results: </strong>127 technical divers were included, three declined participation, leaving 124 cases for analysis. DCS was the most frequent condition (n = 105) followed by IPO (n = 16) and gas toxicity (n = 3). Median age was 45 [IQR 37-53] years, and 113 (91%) were male. Rebreathers were used in 94 (75.8%) cases and helium-based mixtures in 77 (62%). Previous diving-related accidents were reported in 36 (29%) cases. IPO occurred mainly after shallower dives in wetsuits and was frequently associated with procedural errors. Among DCS cases isolated musculoskeletal DCS predominated (n = 36), whereas spinal involvement was less frequent. When indicated, median recompression delay was 238 [IQR 135-555] minutes. Unfavourable outcomes occurred in 26 (25%) DCS cases, primarily with bone or inner-ear involvement.</p><p><strong>Conclusions: </strong>Technical diving accidents exhibit distinct patterns from recreational diving, notably greater musculoskeletal involvement and a possible increased risk of dysbaric osteonecrosis (DON). Current evidence does not support different management, but the risk of potential initially silent bone lesions should not be overlooked. Further research on helium-related risks and hyperbaric treatment's role in DON prevention is needed.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 2","pages":"125-136"},"PeriodicalIF":1.3,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13357026/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249707","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":"Quantifying discrepancy between indicated and actual oxygen flow rates delivered by Comweld Ezi-flow low and standard flowmeters under hyperbaric conditions: a technical report.","authors":"Yoav Aufgang, Bridget Devaney, Jason Chan, Ian Millar, Theo Tsouras","doi":"10.28920/dhm56.2.154-160","DOIUrl":"10.28920/dhm56.2.154-160","url":null,"abstract":"<p><strong>Introduction: </strong>During clinical use of extracorporeal membrane oxygenation (ECMO) in hyperbaric conditions at our centre, upward titration of indicated sweep gas flow rates is required to maintain adequate CO₂ clearance. This project measured the impact of hyperbaric pressure on oxygen flow rates delivered by the Comweld Ezi-Flow flowmeters used in our centre.</p><p><strong>Methods: </strong>Oxygen flow rates through Comweld Ezi-flow standard and low oxygen gas flowmeters were set at 101.3 kPa (1 atmosphere absolute [atm abs]) and then measured at intervals up to 284 kPa (2.8 atm abs) using a calibrated gas flow analyser, with cross verification against a small Douglas bag test type apparatus. During testing, the chamber was compressed and decompressed at a rate of 10 kPa·min⁻¹. Flow rates during chamber compression and decompression were compared.</p><p><strong>Results: </strong>The indicated rate of oxygen gas flow through the unadjusted flowmeters changed minimally - typically rising by a maximum of half of the diameter of the indicator ball. The actual (volumetric) flow, tested across indicated flow rates from 3 to 12 L·min⁻¹, was consistently reduced by approximately 50% as the chamber pressure increased from 101.3 to 284 kPa (1 to 2.8 atm abs). A slightly smaller reduction was observed when assessing the low flowmeter across the same pressure range; reductions of 40.0 and 43.3% were demonstrated at 0.3 to 0.6 L·min⁻¹ respectively. Differences in flow rates between compression and decompression were minor except at the very lowest flows.</p><p><strong>Conclusions: </strong>At 284 kPa (2.8 atm abs), actual volumetric flow of oxygen through Comweld Ezi-Flow flowmeters is dramatically reduced and this needs appropriate compensation to ensure therapeutic aims are achieved.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 2","pages":"154-160"},"PeriodicalIF":1.3,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13357028/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249633","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":"Recreational and technical rebreather fatalities and diving safety status.","authors":"Frauke Tillmans, Camilo Saraiva, Sherri Ferguson, Emmanuel Dugrenot, S Lesley Blogg","doi":"10.28920/dhm56.2.185-190","DOIUrl":"10.28920/dhm56.2.185-190","url":null,"abstract":"<p><strong>Introduction: </strong>The Divers Alert Network (DAN) aims to provide safety information for all types of diving. Assessing the number of active closed-circuit rebreather (CCR) divers is difficult, as pertinent information is often not available. This review aims to give an overview of global use and safety of CCR diving equipment from 2013-2022.</p><p><strong>Methods: </strong>Data were combined and assessed from various DAN internal and public sources on CCR diver demographics, fatalities, and CCR sales.</p><p><strong>Results: </strong>Over the past 10 years, the number of certified CCR divers has increased from an estimated 2,000 in 2013, to 3,000 in 2022. There has been an increase in growth in CCR sales over a five-year period from 2018, with around 25,000 to 35,000 units on the market today; rebreather divers are a growing community. There were 241 confirmed CCR fatalities from 2013-2022, mean 24 (SD 6) per year. Most fatal accidents involved dives made between 40-80 m (130-260 ft) depth. Cause of death is difficult to establish due to lack of detail and dive-specific training for the medical examiner. The estimated death rate is 1.8-3.8 deaths per 100,000 CCR dives although these values are derived from limited data.</p><p><strong>Conclusions: </strong>Not enough information is made available to address CCR accident analysis effectively, perhaps stemming from family reticence to discuss the incident, fear of litigation, and/or lack of diving knowledge reducing the useful information. DAN continues to collect CCR data, but increased collaboration between training bodies, equipment providers, and comprehensive reporting of incidents is needed to reveal the true picture.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 2","pages":"185-190"},"PeriodicalIF":1.3,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13357027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249712","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":"Cerebral arterial oxygen embolism as a complication of hyperbaric oxygen treatment: a case report.","authors":"Rahulkumar Ramchandani, Bridget Devaney, Ashish Jaison, Neil Banham, Stephan Roehr","doi":"10.28920/dhm56.2.198-202","DOIUrl":"10.28920/dhm56.2.198-202","url":null,"abstract":"<p><p>Cerebral arterial gas embolism (CAGE) is a recognised complication of diving-related barotrauma and of medical procedures whereby gas enters the vascular system. CAGE is a principal indication for hyperbaric oxygen treatment (HBOT). In contrast, CAGE resulting from HBOT itself is exceedingly rare. We describe the case of a 73-year-old man undergoing his first session of HBOT for a chronic lower limb wound, who developed acute focal neurological deficits during decompression. He had no known respiratory disease or smoking history. Immediate assessment demonstrated stable physiology. Initial computed tomography (CT) scan of the brain and neck vessels and perfusion imaging did not show any evidence of thrombus or intravascular gas, and partial neurological recovery occurred over several hours. Subsequent magnetic resonance imaging of the brain demonstrated acute infarction involving the left precentral and postcentral gyri. High-resolution CT chest revealed multiple bilateral thin-walled pulmonary cysts, including a left upper lobe cyst with an air-fluid level consistent with recent barotrauma. A transient broncho-venous fistula allowing arterial oxygen embolisation during decompression was considered the most plausible mechanism. The patient improved with supportive management and was discharged with minimal residuae. This case highlights an exceptionally rare but serious complication of HBOT and underscores the importance of vigilance during decompression and careful consideration of occult pulmonary pathology.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 2","pages":"198-202"},"PeriodicalIF":1.3,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13357025/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249722","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":"Efficacy and safety of potential irrigation diluents following 'caustic cocktail' ingestion.","authors":"Adam Lee, Catherine Moore, Adam Griffiths","doi":"10.28920/dhm56.1.83-87","DOIUrl":"10.28920/dhm56.1.83-87","url":null,"abstract":"<p><p>Closed circuit rebreather (CCR) diving sets use soda lime, a sodium hydroxide-based 'scrubber' substance to remove CO₂ from exhaled breathing gas thus prolonging dive time and efficiency. Inadvertent water ingress into the set may result in reaction with the scrubber and a highly alkaline solution known as a 'caustic cocktail' may be formed. Ingestion or aspiration of this solution can cause severe chemical burns. Irrigation with freshwater is the mainstay of initial treatment of 'caustic cocktail' injuries in CCR divers. Published advice advises divers never to use acidic diluents to irrigate and neutralise a caustic cocktail solution due to concerns over the potentially exothermic nature of the neutralisation reaction. However, there is limited available evidence to support this advice, and it was felt that further research into the best treatment options available for caustic cocktails is required. This study used an in vitro model of an ingested caustic cocktail to investigate pH and temperature changes after adding different diluents (including acidic diluents orange juice or coca cola) to a solution of sodium hydroxide. Acidic diluents reduce pH significantly more than neutral diluents with a respective mean drop in pH of 5.99 compared to 0.78 (P = 0.015). There is no statistically significant difference in temperature change noted between the two types of diluent (P = 0.32) with no exothermia generated. We propose that orange juice or coca cola are more effective irrigation solutions than fresh or seawater, and that advice to divers who use CCRs could change.</p>","PeriodicalId":11296,"journal":{"name":"Diving and hyperbaric medicine","volume":"56 1","pages":"83-87"},"PeriodicalIF":1.3,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13654614/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147509222","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}