2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):245−252. doi: 10.28920/dhm49.4.245-252. PMID: 31828742.

The myopic shift associated with hyperbaric oxygen administration is reduced when using a mask delivery system compared to a hood – a randomised controlled trial 

Michael H Bennett1,2, Cheng FB Hui1,2, Hooi G See3, Kwan L Au-Yeung4, Christopher Tan5, Stephanie Watson1,6

1 Prince of Wales Clinical School, University of New South Wales, Sydney, Australia
2 Department of Diving and Hyperbaric Medicine, Prince of Wales Hospital, Sydney, Australia
3 Division of Anaesthesiology and Perioperative Medicine, Singapore General Hospital, Singapore
4 Department of Emergency Medicine, Princess Elizabeth Hospital, Hong Kong
5 Department of Anaesthesia, The Wollongong Hospital, Wollongong, Australia
6 Save Sight Institute, Discipline of Ophthalmology, The University of Sydney, Sydney, Australia

Corresponding author: Professor MH Bennett, Prince of Wales Clinical School and Academic Director, Wales Anaesthesia,
Ground Floor, East Wing Edmund Blackett Building, Prince of Wales Hospital, Barker Street, Randwick, NSW 2031, Australia
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Key words
Side effects; Hyperbaric oxygen; Ophthalmology; Myopia; Vision

Abstract
(Bennett MH, Hui CF, See HG, Au-Yeung KL, Tan C, Watson S. The myopic shift associated with hyperbaric oxygen administration is reduced when using a mask delivery system compared to a hood – a randomised controlled trial. Diving and Hyperbaric Medicine. 2019 December 20;49(4):245–252. doi: 10.28920/dhm49.4.245-252PMID: 31828742.)
Introduction: A temporary myopic shift is a well-recognized complication of hyperbaric oxygen treatment (HBOT). Oxidation of proteins in the crystalline lens is the likely cause. Direct exposure of the eye to hyperbaric oxygen may exacerbate the effect. Our aim was to measure the magnitude of the myopic shift over a course of HBOT when using two different methods of oxygen delivery.
Methods: We conducted a randomised trial of oxygen delivery via hood versus oronasal mask during a course of 20 and 30 HBOT sessions. Subjective refraction was performed at baseline and after 20 and 30 sessions. We repeated these measurements at four and 12 weeks after completion of the course in those available for assessment. 
Results: We enrolled 120 patients (mean age 57.6 (SD 11.2) years; 81% male). The myopic shift was significantly greater after both 20 and 30 sessions in those patients using the hood. At 20 treatments: refractory change was -0.92 D with hood versus -0.52 D with mask, difference 0.40 D (95% CI 0.22 to 0.57, P < 0.0001); at 30 treatments: -1.25 D with hood versus -0.63 with mask, difference 0.62 D (95% CI 0.39 to 0.84, P < 0.0001). Recovery was slower and less complete in the hood group at both four and 12 weeks.
Conclusions: Myopic shift is common following HBOT and more pronounced using a hood system than an oronasal mask. Recovery may be slower and less complete using a hood. Our data support the use of an oronasal mask in an air environment when possible.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):253–258. doi: 10.28920/dhm49.4.253-258. PMID: 31828743.

Protective effect of hyperbaric oxygen treatment on rat intestinal mucosa after mesenteric ischaemia and reperfusion

Kurtuluş Açiksari1, Seracettin Eğin2, Gülçin Hepgül3, Bengüsu Mirasoğlu4, Gamze Tanriverdi5, Devrim S Kanber6, Sibel Demirci5, Halil Doğan7, Doğaç N Özüçelik8, Akın S Toklu4, İsmail Seçkin5, Hakan T Yanar9

1 Department of Emergency Medicine, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey
2 Department of General Surgery, MoH Okmeydanı Training and Research Hospital, Istanbul, Turkey
3 Department of General Surgery, Bagcilar Training and Research Hospital, Istanbul, Turkey
4 Department of Underwater and Hyperbaric Medicine, Faculty of Medicine, Istanbul University, Istanbul, Turkey
5 Department of Histology and Embryology, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey
6 Department of Biophysics, Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey
7 Department of Emergency Medicine, MoH Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Istanbul, Turkey
8 Health Sciences Faculty, Istanbul University, Istanbul, Turkey
9 Department of General Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey

Corresponding author: Assistant Professor Kurtuluş Açiksari, Department of Emergency Medicine, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey
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Key words
Mesenteric ischaemia; Ischaemia-reperfusion injury; Histology; Experimental study

Abstract
(Açiksari K, Eğin S, Hepgül G, Mirasoğlu B, Tanriverdi G, Kanber DS, Demirci S, Doğan H, Özüçelik DN, Toklu AS, Seçkin I, Yanar HT. Protective effect of hyperbaric oxygen therapy on rat intestinal mucosa after mesenteric ischaemia and reperfusion. Diving and Hyperbaric Medicine. 2019 December 20;49(4):253–258. doi: 10.28920/dhm49.4.253-258. PMID: 31828743.)
Introduction: Mesenteric ischaemia results from a lack of adequate blood flow to and oxygenation of the mesentery and intestines. The aim of the present study was to evaluate the effect of hyperbaric oxygen treatment (HBOT) on the healing process in intestinal mucosa of rats undergoing mesenteric ischaemia and reperfusion.
Methods: Thirty-two Wistar-Albino rats were divided into four groups of eight: 1) ischaemia/reperfusion (I/R); 2) sham operation; 3) I/R+HBOT started 6 hours after reperfusion; 4) I/R+HBOT started 12 hours after reperfusion. In the I/R groups, a vascular clamp was placed across the superior mesenteric artery to occlude arterial circulation for 60 minutes, followed by reperfusion. A dose of HBOT consisted of 100% oxygen breathing for 90 minutes at 2.5 atmospheres absolute pressure. Thirteen doses of HBOT were administered after ischaemia. The rats were sacrificed on the eighth day, and their intestinal tissues were harvested for histopathologic analysis. The tissue levels of catalase, malondialdehyde, and glutathione were determined.
Results: The histopathological scores (HSCORE) were consistent with macroscopic examinations. The scores were significantly higher (worse) in Group 1 compared to Group 2, Group 3, and Group 4 (for all comparisons, P < 0.05). Group 4’s HSCORE was significantly higher than those of Group 2 and Group 3 (for both comparisons P < 0.05). Group 3’s HSCOREs were only marginally higher than Group 2. Group 3 exhibited higher glutathione levels than Group 1 (P < 0.05). There were no significant differences across the groups with respect to malondialdehyde and catalase levels.
Conclusion: A beneficial effect of HBOT was observed on oxidative stress and inflammation in acute mesenteric ischaemia-reperfusion.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):259–265. doi: 10.28920/dhm49.4.259-265. PMID: 31828744.

Decompression illness (DCI) in Finland 1999–2018: Special emphasis on technical diving

Richard V Lundell, Olli Arola, Jari Suvilehto, Juha Kuokkanen, Mika Valtonen, Anne K Räisänen-Sokolowski

1 Diving Medical Centre, Centre for Military Medicine, Finnish Defence Forces, Helsinki, Finland
2 Helsinki University, Helsinki, Finland
3 National Hyperbaric Oxygen Therapy Center, Intensive Care Unit, Turku University Hospital, Turku, Finland
4 Hyperbaric Center Medioxygen, Helsinki, Finland
5 Department of Pathology, HUSLAB, Helsinki University Hospital, Helsinki, Finland

Corresponding author: Dr Richard Lundell, Sähkölaitoksentie 4, 00860 Helsinki, Finland
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Key words
Decompression sickness; Diving; Arctic diving; Hyperbaric oxygen treatment; First aid oxygen; Epidemiology

Abstract
(Lundell RV, Arola O, Suvilehto J, Kuokkanen J, Valtonen M, Räisänen-Sokolowski AK. Decompression illness (DCI) in Finland 1999–2018: Special emphasis on technical diving. Diving and Hyperbaric Medicine. 2019 December 20;49(4):259–265. doi: 10.28920/dhm49.4.259-265. PMID: 31828744.)
Introduction: This is the first published study on decompression illness (DCI) and its treatment in Finland. Diving conditions are demanding, as even in the summer the water temperature below 20 meters’ sea/fresh water (msw/mfw) is 4–10°C. Technical diving has become more popular over the years, so the emphasis of this study was to describe DCI in technical divers and compare it with non-technical recreational divers.
Methods: This study includes by estimation over 95% of all hyperbaric oxygen-treated DCI patients during the years 1999–2018 (n = 571). The cases were divided into technical divers (n = 200) and non-technical divers (n = 371). We focused on the differences between these two groups. Technical diving was defined as the usage of mixed breathing gases, closed circuit rebreather diving or planned decompression diving.
Results: The mean annual number of treated DCI cases in Finland was 29 (range 16–38). The number of divers treated possibly indicate a shift towards technical diving. Technical dives were deeper and longer and were mainly performed in cold water or an overhead environment. Technical divers were more likely to utilize first aid 100% oxygen (FAO2) and sought medical attention earlier than non-technical divers. Symptom profiles were similar in both groups. Recompression was performed using USN Treatment Table Six in the majority of the cases and resulted in good final outcome. Eighty two percent were asymptomatic on completion of all recompression treatment(s).
Conclusion: This 20-year observational study indicates a shift towards technical diving, and hence a more demanding and challenging style of diving among Finnish divers, with a surprisingly constant number of DCI cases over the years. There is still need for improvement in divers’ education in use of FAO2 for DCI symptoms. Fortunately, the outcome after recompression therapy is generally successful.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):266–275. doi: 10.28920/dhm49.4.266-275. PMID: 31828745.

Evaluating the thermal protection provided by a 2‒3 mm wet suit during fin diving in shallow water with a temperature of 16‒20°C

Dror Ofir, Yoav Yanir, Mirit Eynan, Yehuda Arieli

1 Israel Naval Medical Institute, Haifa, Israel
2 Department of Otolaryngology – Head and Neck Surgery, Carmel Medical Centre, Haifa, Israel

Corresponding author: Dr Dror Ofir, The Israel Naval Medical Institute (INMI), Box 22, Rambam Health Care Campus, PO Box 9602, 3109601, Haifa, Israel
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Key words
Cold; Immersion; Military diving; Rebreathers; Closed circuit; Thermodynamics; Vasoconstriction

Abstract
(Ofir D, Yanir Y, Eynan M, Arieli Y. Evaluating the thermal protection provided by a 2–3 mm wet suit during fin diving in shallow water with a temperature of 16–20°C. Diving and Hyperbaric Medicine. 2019 December 20;49(4):266–275. doi: 10.28920/dhm49.4.266-275. PMID: 31828745.)
Introduction: The purpose of the study was to evaluate the thermal protection provided by a 2–3 mm surfing wet suit during at least two hours of fin diving in shallow water with a temperature of 16–20°C. We examined the effect of wearing the suit while diving in cold water on cognitive performance, muscle strength, and hand motor function.
Methods: Subjects were six male well-trained rebreather divers, 19–23 years old, acclimatised to cold. They attended the laboratory on three separate occasions, when we conducted the experiment at one of three temperatures, 16, 18, and 20°C. Core temperature (gastrointestinal system), skin temperature, oxygen consumption, and cold perception were evaluated during the test. Before and immediately after the dives, subjects performed a series of cognitive, manual dexterity, and muscle strength tests.
Results: Core temperature decreased by 0.35–0.81°C over the two hours at all three water temperatures. No subject reached a core temperature below 35°C. The decrease in upper body skin temperature during the two hour dive ranged between 5.97 and 8.41°C (P < 0.05). Two hours diving in 16–20°C water resulted in a significant increase in the time taken to perform the task of unlinking and reassembling four shackles (~30% longer, P < 0.05). No effect was found on the cognitive or muscle strength tests.
Conclusions: A 2–3 mm wet suit provides adequate thermal protection in trained and cold-acclimatised young males engaged in active diving in shallow water with a temperature of 16°C and above.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):276–282. doi: 10.28920/dhm49.4.276-282. PMID: 31828746.

Inhibition of NR2B-containing NMDA receptors during nitrogen narcosis

Bin Peng, Du-Du Hao, Xia Li, Guo-Hua Wang, Zong-Yu Guan, Zheng-Lin Jiang

1 Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China

Corresponding author: Dr Zheng-Lin Jiang. Department of Neurophysiology and Neuropharmacology, Institute of Special Environmental Medicine, Nantong University, 9 Seyuan Road, Chongchuan District, Nantong, Jiangsu 226019, China
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Key words
Brain; Hippocampus; Hyperbaric medicine; Neuron; NMDA receptor

Abstract
(Peng B, Hao D-D, Li X, Wang G-H, Guan Z-Y, Jiang Z-L. Inhibition of NR2B-containing NMDA receptors during nitrogen narcosis. Diving and Hyperbaric Medicine. 2019 December 20;49(4):276–282. doi: 10.28920/dhm49.4.276-282. PMID: 31828746.)
Introduction: When humans breathe compressed air or N2-O2 mixtures at three to four atmospheres pressure, they will experience nitrogen narcosis that may possibly lead to a diving accident, but the underlying mechanisms remain unclear.
Methods: Mice were exposed to 1.6 MPa breathing a N2-O2 mixture adjusted to deliver an inspired PO2 of 32–42 kPa. The electroencephalogram (EEG) and forced swimming test were used to evaluate the narcotic effect of nitrogen. Neuronal activity was observed via c-Fos expression in cortex and hippocampus tissue after decompressing to the surface. To further investigate underlying molecular mechanisms, we incubated cultured hippocampal neurons with various NMDA concentrations, and measured expression of NMDA receptors and its down-stream signal with or without 1.6 MPa N2-O2 exposure.
Results: Both the frequency of the EEG and the drowning time using the forced swimming test were significantly decreased during exposure to 1.6 MPa N2-O2 (P < 0.001). Additionally, in cultured hippocampal neurons, the increased levels of phosphorylated NR2B and cAMP-response element binding protein (CREB) induced by NMDA stimulation were significantly inhibited by exposure to 1.6 MPa N2-O2.
Conclusions: Our findings indicated that NR2B-containing NMDA receptors were inhibited during nitrogen narcosis.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):283–290. doi: 10.28920/dhm49.4.283-290. PMID: 31828747.

Longitudinal screening of hearing threshold in navy divers: is diving really a hazard?

Thijs T Wingelaar, Edwin L Endert, Rigo Hoencamp, Peter-Jan AM van Ooij, Rob A van Hulst

1 Diving Medical Center, Royal Netherlands Navy, Den Helder, the Netherlands
2 Department of Anesthesiology, Amsterdam University Medical Center, Amsterdam, the Netherlands
3 Department of Surgery, Alrijne Hospital, Leiderdorp, the Netherlands
4 Defense Healthcare Organisation, Ministry of Defence, Utrecht, the Netherlands
5 Leiden University Medical Center, Leiden, the Netherlands

Corresponding author: Thijs Wingelaar, Royal Netherlands Navy Diving Medical Center, Rijkszee en marinehaven. 1780 CA Den Helder, the Netherlands
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Key words
Fitness to dive; Health surveillance; Hearing loss; Audiology; Military diving

Abstract
(Wingelaar TT, Endert EL, Hoencamp R, van Ooij PJAM, van Hulst RA. Longitudinal screening of hearing threshold in navy divers: is diving really a hazard? Diving and Hyperbaric Medicine. 2019 December 20;49(4):283–290. doi: 10.28920/dhm49.4.283-290. PMID: 31828747.)
Introduction: Hearing loss (HL) is common in the adult working population. It is widely assumed that diving is a risk factor for HL. However, studies with sufficient follow-up comparing HL in divers to non-divers are limited. This study aimed to assess the hearing threshold (HT) of Royal Netherlands Navy divers who had been diving for more than 15 years and to compare it to the ISO standard 7029:2017 reference table.
Methods: In this 25-year retrospective cohort study the Royal Netherlands Navy Diving Medical Centre audited the medical records of 1,117 Navy divers. Yearly dive medical assessments were performed according to professional standards, including audiometry. HTs were compared to the ISO 7029:2017 reference table, including Z-distribution, using paired t-tests.
Results: Thirty-five divers were included who had been diving for 15 years or longer. The HT increased significantly in nine of the 16 measured frequencies, while the Z-score decreased significantly in nine of the 16 tested frequencies (eight in both ears). In the 25-year follow-up the pattern was more obvious, with one significantly increased HT, and 10 significantly decreased Z-scores.
Discussion: The absolute HT increases after 15 years of military diving, but less than would be expected from normal age-related deterioration. Moreover, when comparing Z-scores, this sample of divers actually hear better than non-divers. We conclude that military diving is not an increased risk for HL compared to regular occupational hazards and suggest withdrawing the requirement for routine yearly audiometric evaluation as part of a dive medical examination.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):291–297. doi: 10.28920/dhm49.4.291-297. PMID: 31828748.

Diving and mental health: the potential benefits and risks from a survey of recreational scuba divers

Marguerite St Leger Dowse, Ben Whalley, Matthew K Waterman, Robert M Conway, Gary R Smerdon

1 DDRC Healthcare, Plymouth, United Kingdom
2 School of Psychology / Cognition, Plymouth University, Plymouth, United Kingdom
3 North Devon District Hospital, Barnstaple United Kingdom

Corresponding author: Marguerite St Leger Dowse, DDRC Healthcare, Hyperbaric Medical Centre, Plymouth Science Park, Research Way, Plymouth PL6 8BU, Devon, United Kingdom
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Key words
Depression; Anxiety; Medical conditions and problems; Psychology; Fitness to dive

Abstract
(St Leger Dowse M, Whalley B, Waterman MK, Conway RM, Smerdon GR. Diving and mental health: the potential benefits and risks from a survey of recreational scuba divers. Diving and Hyperbaric Medicine. 2019 December 20;49(4):291–297. doi: 10.28920/dhm49.4.291-297. PMID: 31828748.)
Introduction: Scuba diving is physically and cognitively demanding. Medical guidance regarding physical and mental health (MH) issues and related prescribed medication is often based on limited evidence. There is a paucity of data concerning diving with MH issues. This survey aimed to investigate the prevalence of MH issues and use of prescription medications among United Kingdom (UK) sport divers, and the rate of non-compliance with current guidance among divers suffering depression and anxiety. The positive effects of scuba diving on MH were also considered.
Methods: An anonymous online survey was publicised through diving exhibitions and social media. Measures included diver and diving demographics; GAD-7 Anxiety and PHQ-9 depression questionnaires; diagnosed current and/or past MH conditions; medication usage; comorbid medical conditions/treatments; disclosure of past/current MH issues; and perceived MH benefits of diving.
Results: Data from 729 respondents revealed MH issues at rates comparable with the general population. Current and/or past MH issues were reported by 111/729, with 60 having active diagnoses, and 45/60 taking prescribed psychotropic medications; 21/45 did not declare their medication on diver self-certification medical forms. The activity of diving was thought to be beneficial to MH by 119/729 respondents.
Conclusions: Divers experienced expected levels of MH issues, but did not comply with current medical guidelines on modifying or abstaining from diving activity or reporting their MH condition. Changes may be needed to diver training to encourage more accurate reporting and aid development of evidence-based protocols. Guidelines could be reconsidered in light of current diver behaviour, risks and potential MH benefits.

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.

Publication Type: Original article


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):298–303. doi: 10.28920/dhm49.4.298-303. PMID: 31828749.

Performance of cartridge and granular carbon dioxide absorbents in a closed-circuit diving rebreather

Nicholas Gant, Hanna van Waart, Edward T Ashworth, Peter Mesley, Simon J Mitchell

1 Department of Exercise Sciences, University of Auckland, New Zealand
2 Department of Anaesthesiology, University of Auckland, New Zealand
3 Lust4Rust Diving Excursions, Auckland, New Zealand
4 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand

Corresponding author: Associate Professor Nicholas Gant, Department of Exercise Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
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Key words
Technical diving; Closed-circuit rebreather; Carbon dioxide; Soda lime; Scrubber; Hypercapnia

Abstract
(Gant N, van Waart H, Ashworth ET, Mesley P, Mitchell SJ. Performance of cartridge and granular carbon dioxide absorbents in a closed-circuit diving rebreather. Diving and Hyperbaric Medicine. 2019 December 20;49(4):298–303. doi: 10.28920/dhm49.4.298-303. PMID: 31828749.)
Introduction: Scrubbers in closed-circuit rebreather systems remove carbon dioxide (CO2) from the exhaled gas. In an attempt to be more user-friendly and efficient, the ExtendAir® non-granular, pre-formed scrubber cartridge has been developed. The cartridge manufacturer claims twice the absorptive capacity of granular CO2 absorbent, with less variability, lower work of breathing, and reduced exposure to caustic chemicals after a flood. To our knowledge there are no published data that support these claims.
Methods: Cartridge (ExtendAir®) and granular (Sofnolime® 797) scrubbers of equal volume and mass were tested five times in an immersed and mechanically ventilated O2ptima rebreather. Exercise protocols involving staged (90 minutes 6 MET, followed by 2 MET) and continuous (6 MET) activity were simulated. We compared: duration until breakthrough, and variability in duration, to endpoints of 1.0 kPa and 0.5 kPa inspired partial pressure of CO2; inspiratory–expiratory pressure difference in the breathing loop; and pH of eluted water after a 5 minute flood.
Results: Mean difference in scrubber endurance was 0–20 % in favour of the ExtendAir® cartridge, depending on exercise protocol and chosen CO2 endpoint. There were no meaningful differences in endpoint variability, inspiratory–expiratory pressure in the loop, or pH in the eluted water after a flood.
Conclusions: Cartridge and granular scrubbers were very similar in duration, variability, ventilation pressures, and causticity after a flood. Our findings were not consistent with claims of substantial superiority for the ExtendAir® cartridge.

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.

Publication Type: Technical report


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):304–305. doi: 10.28920/dhm49.4.304-305. PMID: 31828750.

Fatal air embolism in a breath-hold diver

Neil DG Banham, John Lippmann

1 Hyperbaric Medicine Unit, Fiona Stanley Hospital, Perth, Australia
2 Australasian Diving Safety Foundation, Melbourne, Australia

Corresponding author: Dr Neil DG Banham, Director, Hyperbaric Medicine Unit, Fiona Stanley Hospital, Perth, Australia
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Key words
Diving deaths; Barotrauma; Breath-hold diving; Scuba; Cerebral arterial gas embolism (CAGE); Pulmonary barotrauma; Case reports

Abstract

(Banham NDG, Lippmann J. Fatal air embolism in a breath-hold diver. Diving and Hyperbaric Medicine. 2019 December 20;49(4):304–305. doi: 10.28920/dhm49.4.304-305. PMID: 31828750.)
Cerebral arterial gas embolism (CAGE) from breath-holding or inadequate exhalation during ascent is a well-recognised complication of scuba diving. It does not usually occur with breath-hold (BH) diving in those with normal lungs, as the volume of gas in the lungs on surfacing cannot exceed what it was on leaving the surface. However, a BH diver who breathes from a compressed gas supply at depth essentially becomes a scuba diver and is at risk of pulmonary barotrauma (PBt) and CAGE on ascent. In this case, a 26-year-old male experienced BH diver breathed from a scuba set at approximately 10 metres' sea water depth and ascended, sustaining massive PBt and CAGE with a fatal outcome. BH and scuba divers, especially those with less experience, need to be well-informed about this potential risk.

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.

Publication Type: Case report


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4)::306–310. doi: 10.28920/dhm49.4.306-310. PMID: 31828751.

A case of Löfgren’s syndrome confused with decompression sickness

Payal S Razdan, Dominique Buteau, Neal W Pollock

1 Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
2 CISSS Chaudière-Appalaches (CHAU-Hôtel-Dieu de Lévis), Hyperbaric Medicine Unit, Lévis, Québec, Canada
3 Family Medicine and Emergency Medicine Department, Faculty of Medicine, Université Laval, Québec, Canada
4 CISSS Chaudière-Appalaches (CHAU-Hôtel-Dieu de Lévis), Hyperbaric Medicine Unit, Emergency Department, Lévis, Quebec, Canada

Corresponding author: Payal S Razdan, Rm 4807, Hôtel-Dieu de Lévis, 143 rue Wolfe, Lévis, QC, Canada, G6V 3Z1
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Key words
Hyperbaric oxygen; Differential diagnosis; Mycobacterium marinum infection; Pulmonary sarcoidosis

Abstract

(Razdan PS, Buteau D, Pollock NW. A case of Löfgren’s syndrome confused with decompression sickness. Diving and Hyperbaric Medicine. 2019 December 20;49(4):306–310. doi: 10.28920/dhm49.4.306-310. PMID: 31828751.)
A broad differential diagnosis is important to provide appropriate care. This may be challenging for conditions like decompression sickness (DCS) which can be easily confused with other conditions. In suspected DCS, treatment may be an important part of the diagnosis. An improvement in symptoms after hyperbaric oxygen treatment (HBOT) is consistent with a DCS event. However, HBOT may also impact symptoms in other conditions, including Löfgren’s syndrome (LS). LS, a poorly understood, clinically distinct phenotype of sarcoidosis, is a complex, multi-system granulomatous inflammatory condition. Like DCS, LS symptoms are heterogeneous and idiosyncratic. We report on a patient initially diagnosed with DCS who presented new symptoms suggestive of LS after HBOT.

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.

Publication Type: Case report


2019 December;49(4)

Diving Hyperb Med. 2019 December;49(4):311–312. doi: 10.28920/dhm49.4.311-312. PMID: 31828752.

Gas micronuclei that underlie decompression bubbles and decompression sickness have most probably been identified – in response to the Letter to the Editor from Dr David Doolette

Ran Arieli

The Israel Naval Medical Institute, Israel Defence Forces Medical Corps, Haifa, Israel; Eliachar Research Laboratory, Western Galilee Medical Centre, Nahariya, Israel

Address for correspondence: 12 Klil-Hakhoresh, Rakefet, D.N. Misgav 2017500, Israel
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Key words
Nanobubbles; Gas micronuclei; Decompression bubbles; Hydrophobicity; Letter to the Editor

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.

Publication Type: Letter to the Editor


 

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