2020 June;50(2)

Diving Hyperb Med. 2020 June 30;(2):90–91. doi: 10.28920/dhm50.2.90-91. PMID: 32557408.

Diving and hyperbaric medicine in the SARS-CoV-2 pandemic

Simon J Mitchell 

Professor Simon J Mitchell, Editor – Diving and Hyperbaric Medicine Journal. Department of Anaesthesiology, University of Auckland. Private Bag 92019, Auckland 1142, New Zealand
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Covid-19; Hyperbaric oxygen treatment; Fitness for diving; Pulmonary barotrauma; Decompression sickness

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: Editorial


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;(2):92–97. doi: 10.28920/dhm50.2.92-97. PMID: 32557409.

Recreational diving-related injury insurance claims among Divers Alert Network Japan members: Retrospective analysis of 321 cases from 2010 to 2014

Yasushi Kojima1,2,3, Akiko Kojima1, Yumi Niizeki1,2,4, Kazuyoshi Yagishita1,2

1 Divers Alert Network Japan (DAN Japan) / Japan Marine Recreation Association, Yokohama, Japan
2 Hyperbaric Medical Center, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
3 Tokio Marine & Nichido Medical Service Co. Ltd., Tokyo, Japan
4 Department of Orthopaedic Surgery, Soka Municipal Hospital, Saitama, Japan

Corresponding author: Dr Yasushi Kojima, Divers Alert Network Japan (DAN Japan) / Japan Marine Recreation Association, 4-43 Honcho, Naka-ku, Yokohama-city, Kanagawa 231-0005, Japan
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Decompression illness; Decompression sickness; Diving incidents; Epidemiology; Injuries; Risk; Trauma

Abstract
(Kojima Y, Kojima A, Niizeki Y, Yagishita K. Recreational diving-related injury insurance claims among Divers Alert Network Japan members: Retrospective analysis of 321 cases from 2010 to 2014. Diving and Hyperbaric Medicine. 2020 June 30;50(2):92–97. doi: 10.28920/dhm50.2.92-97. PMID: 32557409.)
Introduction: Monitoring trends in diving-related injuries enables implementation of effective safety measures. Divers Alert Network Japan (DAN Japan) membership includes insurance covering recreational diving-related injuries and fatalities. Use of claim data provides both a known denominator and demographic data about injured members.
Methods: The study analysed 325 insurance claims reported to DAN Japan from 2010 to 2014. Four fatalities were excluded, leaving 321 claims for analysis. Claimants were divided into three age groups: young adults (< 40 years); middle-aged (40–59 years) and older adults (≥ 60 years). The total injury claims rate (ICR), decompression illness (DCI) rate (DCR) and trauma rate (TCR) were calculated. Differences between the sexes within each age group were analysed.
Results: The total number of DAN Japan member-years in the period was 80,617, with a mean age of 45 years. Claims were made by 153 males and 168 females with a mean and median age of 46 years. Trauma was the most frequent reason for a claim (113 cases, 35%), followed by DCI (109 cases, 34%). The ICR (per 104 member-years) was 39.8 (95% confidence interval 35.5 to 44.2) and the TCR was 14.0 (11.4 to 16.6). For every age group, the ICR and TCR were significantly higher for females than males. The DCR was 13.5 (11.0 to 16.1) and did not significantly differ between the sexes.
Conclusions: The incidence of trauma-related diving injuries exceeds that of claims related to DCI. Females appear to have a higher risk of injury than the general diving population.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):98–104. doi: 10.28920/dhm50.2.98-104. PMID: 32557410.

Medical conditions in scuba diving fatality victims in Australia, 2001 to 2013

John Lippmann1,2, David McD Taylor3,4

1 Australasian Diving Safety Foundation, Canterbury, Victoria, Australia
2 Department of Public Health and Preventive Medicine, Monash University, Victoria, Australia
3 Emergency Department, Austin Hospital, Victoria, Australia
4 Department of Medicine, Melbourne University, Victoria, Australia

Corresponding author: Dr John Lippmann, P.O. Box 478, Canterbury VIC 3126, Australia
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Autopsy; Cardiac; Diving deaths; Fitness to dive; Immersion; Medical conditions and problems

Abstract
(Lippmann J, Taylor D McD. Medical conditions in scuba diving fatality victims in Australia, 2001 to 2013. Diving and Hyperbaric Medicine. 2020 June 30;50(2):98–104. doi: 10.28920/dhm50.2.98-104. PMID: 32557410.)
Introduction: This study identified pre-existing medical conditions among scuba diving fatalities in Australia from 2001 to 2013, inclusive, and assessed whether these conditions likely contributed to the deaths.
Methods: The National Coronial Information System (NCIS) was searched for scuba diving-related cases during 2001–2013, inclusive. Coronial findings, witness and police reports, medical histories, and autopsy and toxicology reports were scrutinised for pre-existing medical conditions and autopsy findings. Predisposing factors, triggers, disabling agents, disabling injuries and causes of death were analysed using a validated template.
Results: There were 126 scuba diving-related fatalities identified during the study period. Forty-six (37%) divers were identified as having a significant medical condition which may have contributed to their incident. The most common condition was ischaemic heart disease (IHD) which had been diagnosed in 15 of the divers. Thirty-two (25%) deaths were attributed to cardiac disabling injuries (DI) such as ischaemic heart disease and arrhythmias, although a cardiac DI was thought likely in another six. Respiratory conditions were implicated in eight (6%) deaths, at least four associated with cerebral arterial gas embolism. At least 14 (11%) divers who had contributory pre-existing medical conditions had been cleared to dive by a medical practitioner within the year prior.
Conclusions: Chronic health-related factors played a major role in almost half of these deaths; primarily cardiac conditions such as IHD and cardiac arrhythmias. Although fitness-to-dive (FTD) assessments have limitations, the high incidence of cardiac-related deaths indicates a need for ‘older’ divers to be medically assessed for FTD.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):105–114. doi: 10.28920/dhm50.2.105-114. PMID: 32557411.

Scuba diving fatalities in Australia, 2001 to 2013: Diver demographics and characteristics

John Lippmann1,2, Christopher Stevenson3, David McD Taylor4,5

1 Australasian Diving Safety Foundation, Canterbury, Victoria, Australia
2 Department of Public Health and Preventive Medicine, Monash University, Victoria, Australia
3 School of Health and Social Development, Deakin University, Melbourne, Australia
4 Emergency Department, Austin Hospital, Victoria, Australia
5 Department of Medicine, Melbourne University, Victoria, Australia

Corresponding author: Dr John Lippmann, P.O. Box 478, Canterbury VIC 3126, Australia
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
DAN – Divers Alert Network; Diving deaths; Diving incidents; Obesity; Research; Solo diving

Abstract
(Lippmann J, Stevenson C, Taylor D McD. Scuba diving fatalities in Australia, 2001 to 2013: Diver demographics and characteristics. Diving and Hyperbaric Medicine. 2020 June 30;50(2):105–114. doi: 10.28920/dhm50.2.105-114. PMID: 32557411.)
Introduction: This study identified characteristics of victims of fatal scuba diving incidents to determine contributing factors and inform appropriate countermeasures.
Methods: The National Coronial Information System (NCIS) was searched to identify scuba diving deaths for 2001–2013, inclusive. Data were extracted from witness and police reports, medical histories and autopsies. Descriptive statistics were used to analyse these data.
Results: There were 126 scuba diving-related fatalities identified during the study period. The mean age was 44 years, 99 (79%) victims were male and 83 (77%) were either overweight or obese. Most deaths occurred in New South Wales and Queensland, often in a commercial setting. Twenty-three (79%) Queensland victims were overseas tourists. At least 52 (41%) were novices and 17 (13%) died during training or an introductory scuba experience. Only 35 (28%) were with a buddy when the incident occurred and at least 81 (64%) were still wearing weights when recovered.
Conclusions: The age of these victims may reflect an older cohort of participants and the associated higher prevalence of chronic medical conditions. The high prevalence of obesity suggests that this may be a risk factor. The high proportion of deaths in overseas tourists highlights an on-going need for appropriate screening and monitoring in what may be a higher risk cohort. The number of deaths that occurred under instruction highlights the importance of careful assessment of the site, prevailing conditions, an appropriate instructor-student ratio and close supervision.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):115–120. doi: 10.28920/dhm50.2.115-120. PMID: 32557412.

Pupillometry is not sensitive to gas narcosis in divers breathing hyperbaric air or normobaric nitrous oxide

Xavier CE Vrijdag1,2, Hanna van Waart1, Jamie W Sleigh1,3, Simon J Mitchell1,4

1 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
2 Deep Dive Dubai, Dubai, United Arab Emirates
3 Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand
4 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand

Corresponding author: Xavier Vrijdag, Department of Anaesthesiology, School of Medicine, University of Auckland, Private bag 92019, Auckland 1142, New Zealand
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Diving research; Nitrogen; Nitrous oxide; Physiology

Abstract
(Vrijdag XCE, van Waart H, Sleigh JW, Mitchell SJ. Pupillometry is not sensitive to gas narcosis in divers breathing hyperbaric air or normobaric nitrous oxide. Diving and Hyperbaric Medicine. 2020 June 30;50(2):115–120. doi: 10.28920/dhm50.2.115-120. PMID: 32557412.)
Introduction: Gas narcosis impairs divers when diving deeper. Pupillometry is sensitive to alcohol intoxication and it has been used in anaesthesia to assess nitrous oxide narcosis. It is a potential novel method to quantify narcosis in diving. The aim of this study was to evaluate pupillometry for objective measurement of narcosis during exposure to hyperbaric air or nitrous oxide.
Method: Pupil size in 16 subjects was recorded directly at surface pressure and during air breathing at 608 kPa (equivalent to 50 metres’ seawater depth) in a hyperbaric chamber. Another 12 subjects were exposed to nitrous oxide at end-tidal percentages of 20, 30 and 40% in random order at surface pressure. Pupil size and pupil light reflex were recorded at baseline and at each level of nitrous oxide exposure.
Results: Pupil size did not significantly change during exposure to hyperbaric air or nitrous oxide. The pupil light reflex, evaluated using percentage constriction and minimum diameter after exposure to a light stimulus, was affected significantly only during the highest nitrous oxide exposure – an end-tidal level of 40%.
Conclusion: Pupillometry is insensitive to the narcotic effect of air at 608 kPa in the dry hyperbaric environment and to the effects of low dose nitrous oxide. Pupillometry is not suitable as a monitoring method for gas narcosis in 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.

Publication Type: Original article


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):121–129. doi: 10.28920/dhm50.2.121-129. PMID: 32557413.

Deep anaesthesia: The Thailand cave rescue and its implications for management of the unconscious diver underwater

Hanna van Waart1, Richard J Harris2, Nicholas Gant3, Xavier CE Vrijdag1, Craig J Challen4, Chanrit Lawthaweesawat5, Simon J Mitchell1,6,7

1 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
2 MedSTAR Emergency Medical Retrieval Service, Adelaide, Australia
3 Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
4 Image Dive Pty Ltd, Wangara DC, Western Australia
5 Medical Association of Thailand, Bangkok, Thailand
6 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
7 Slark Hyperbaric Unit, North Shore Hospital, Auckland, New Zealand

Corresponding author: Professor Simon Mitchell, Department of Anaesthesiology, School of Medicine, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Cave diving; Ketamine; Anaesthesia; Anesthesia; Unconsciousness; Full face mask; Equipment

Abstract
(van Waart H, Harris RJ, Gant N, Vrijdag XCE, Challen CJ, Lawthaweesawat C, Mitchell SJ. Deep anaesthesia: The Thailand cave rescue and its implications for management of the unconscious diver underwater. Diving and Hyperbaric Medicine. 2020 June 30;50(2):121–129. doi: 10.28920/dhm50.2.121-129. PMID: 32557413.)
Introduction: In 2018 12 children and one adult were anaesthetised before being extricated through over a kilometre of flooded cave in Thailand. Full face dive masks (FFMs) putatively capable of maintaining constant positive airway pressure (CPAP) were employed. Here we describe the anaesthetic intervention and investigate the CPAP capability of the FFM.
Methods: Pressure was measured inside and outside the Interspiro Divator FFM during 10 tidal and 10 vital capacity breaths in divers at the surface and submerged with the mask deployed on open-circuit scuba (10 divers); and a closed-circuit rebreather (five divers). Relative in-mask pressure was calculated as the difference between inside and outside pressures. We also measured the in-mask pressure generated by activation of the second stage regulator purge valve in open-circuit mode.
Results: When submerged in open-circuit mode the mean relative in-mask pressure remained positive in normal tidal breathing (inhalation 0.6 kPa [95% CI 0.3–0.9]; exhalation 1.1 [0.8–1.4]) and vital capacity breathing (inhalation 0.8 [0.4–1.1]; exhalation
1.2 [0.9–1.4]). As expected, the relative in-mask pressure was predominantly negative when used on closed-circuit with back mounted counter-lungs due to a negative static lung load. Mean in-mask pressure during purge valve operation was 3.99 kPa (approximately equal to 40 cmH2O) (range: 2.56 to 5.3 kPa).
Conclusions: The CPAP function of the Interspiro Divator FFM works well configured with open-circuit scuba. This may have contributed to the success of the Thailand cave rescue. Caution is required in generalising this success to other diving scenarios.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):130–134. doi: 10.28920/dhm50.2.130-134. PMID: 32557414.

Anxiety impact on scuba performance and underwater cognitive processing ability

Feng-Hua Tsai1, Wen-Lan Wu2, Jing-Min Liang2, Hsiu-Tao Hsu1, Te-Yuan Chen2,3

1 Center for General Education, National Sun Yat-Sen University, Kaohsiung, Taiwan
2 Department of Sports Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
3 Department of Neurosurgery, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan

Corresponding author: Dr Te-Yuan Chen, Department of Neurosurgery, E-Da Hospital, 1 Yida Road, Jiaosu Village, Yanchao District, Kaohsiung City 82445, Taiwan
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Diving research; Personality; Psychology; Scuba diving; Training

Abstract
(Tsai F-H, Wu W-L, Liang J-M, Hsu H-T, Chen T-Y. Anxiety impact on scuba performance and underwater cognitive processing ability. Diving and Hyperbaric Medicine. 2020 June 30;50(2):130–134. doi: 10.28920/dhm50.2.130-134. PMID: 32557414.)
Introduction: Anxiety is a substantial consideration in scuba diving and may influence a diver’s performance and cognitive activities. This study aimed to simultaneously observe the effect of anxiety trait on actual diving performance and underwater cognitive processing ability.
Methods: Twenty-seven scuba divers completed the STAI-T component of the State-Trait Anxiety Inventory, and were subdivided into two groups on the basis of trait anxiety scores ≥ 39 and < 39. Scuba diving performance was measured in a pool. The completion time of four standardised scuba skills was recorded by a diving instructor. The correct completion rate and response time for a cognitive function assessment (number-Stroop test) were measured both on land (‘dry’) and underwater at 5 metres’ fresh water.
Results: Anxiety trait was associated with prolonged mask clearing: mean completion time 7.1 (SD 3.2) s vs. 10.8 (5.4) s in low and high anxiety trait divers respectively (P = 0.04). Low (vs high) anxiety trait divers had reduced response times for the number-Stroop test: 49.8 (3.0) s vs. 53.3 (5.4) s (P = 0.04) dry, and 64.4 (5.0) s vs. 72.5 (5.5) s (P < 0.01) underwater. Performance of other skills was not significantly affected by trait anxiety nor correlated with the number-Stroop test results.
Conclusions: Personal anxiety trait prolongs mask clearing and underwater cognitive processing ability but the latter did not affect execution of other underwater scuba diving skills.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):135–143. doi: 10.28920/dhm50.2.135-143. PMID: 32557415.

Recreational diving in persons with type 1 and type 2 diabetes: Advancing capabilities and recommendations

Johan H Jendle1,2, Peter Adolfsson2,3,4, Neal W Pollock5,6

1 School of Medicine, Institution of Medical Sciences, Örebro University, Örebro, Sweden
2 Diabetes Endocrinology and Metabolism Research Center, Örebro University, Örebro, Sweden
3 Department of Pediatrics, The Hospital of Halland, Kungsbacka, Sweden
4 Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
5 Department of Kinesiology, Université Laval, Quebec, Canada
6 Centre de médecine de plongée du Québec, CISSS Chaudière-Appalaches (CHAU-Hôtel-Dieu de Lévis) Levis, Québec, Canada

Corresponding author: Professor Johan H Jendle, Institution of Medical Sciences, Örebro University, Campus USÖ, SE-70182 Örebro, Sweden
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Diving safety; Endocrinology; Health; Medical conditions and problems; Medications; Risk management

Abstract

(Jendle JH, Adolfsson P, Pollock NW. Recreational diving in persons with type 1 and type 2 diabetes: Advancing capabilities and recommendations. Diving and Hyperbaric Medicine. 2020 June 30;50(2):135–143. doi: 10.28920/dhm50.2.135-143. PMID: 32557415.)
Diving by persons with diabetes has long been conducted, with formal guidelines published in the early 1990s. Subsequent consensus guidelines produced following a 2005 workshop helped to advance the recognition of relevant issues and promote discussion. The guidelines were intended as an interim step in guidance, with the expectation that revisions should follow the gathering of additional data and experience. Recent and ongoing developments in pharmacology and technology can further aid in reducing the risk of hypoglycemia, a critical acute concern of diving with diabetes. Careful and periodic evaluation remains crucial to ensure that participation in diving activity is appropriate. Close self-monitoring, thoughtful adjustments of medications and meals, and careful review of the individual response to diving can assist in optimising control and ensuring safety. Open communication with diving partners, support personnel, and medical monitors is important to ensure that all are prepared to effectively assist in case of need. Ongoing vigilance, best practice, including graduated clearance for diving exposures and adverse event reporting, are all required to ensure the safety of diving with diabetes and to promote community understanding and acceptance.

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: Review article


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):144–151. doi: 10.28920/dhm50.2.144-151. PMID: 32557416.

Evaluation of the Abbot FreeStyle Optium Neo H blood glucose meter in the hyperbaric oxygen environment

Carol R Baines1, P David Cooper1, Geraldine A O’Rourke2, Charne Miller3

1 Department of Diving and Hyperbaric Medicine, Royal Hobart Hospital, Hobart, Tasmania, Australia
2 Office of the Chief Nurse and Midwife, Health Professional Policy and Advisory Services, Department of Health, Tasmania, Australia
3 Alfred Health Clinical School, La Trobe University, Prahran, Victoria, Australia

Corresponding author: Carol R Baines, Department of Diving and Hyperbaric Medicine, Royal Hobart Hospital, Liverpool Street, Hobart, Tasmania, Australia 7000
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Blood glucose level; Glucose monitoring; Diabetes; Hyperbaric oxygen treatment

Abstract
(Baines CR, Cooper PD, O’Rourke GA, Miller C. Evaluation of the Abbot FreeStyle Optium Neo H blood glucose meter in the hyperbaric oxygen environment. Diving and Hyperbaric Medicine. 2020 June 30;50(2):144–151. doi: 10.28920/dhm50.2.144-151. PMID: 32557416.)
Introduction: This study investigated the effects of hyperbaric oxygen treatment (HBOT) on the accuracy and reliability of point-of-care fingertip capillary blood glucose values in euglycaemic non-diabetic participants compared against venous serum blood glucose samples processed in an accredited pathology laboratory.
Method: Ten non-diabetic hyperbaric staff members (age 35–55 years) underwent a standard 243 kPa HBOT exposure for 95 minutes. Blood glucose levels were measured via (i) finger-prick capillary test using the FreeStyle Optium™ Neo H glucometer and (ii) venous serum test using the Cobas 6000 laboratory analyser. Samples were taken at (T1) 0 minutes (pre-HBOT), (T2) 25 minutes, and (T3) 55 minutes into HBOT.
Results: All participants were euglycaemic at T1 (BGL 3.8–5.4 mmol·L-1). The highest venous serum value was 5.90 mmol·L-1 at T3 and the highest capillary value was 6.30 mmol·L-1 at T1. Post hoc tests showed a statistically significant difference between the mean capillary result pre-dive (T1) and readings at T2 (P = 0.001) and T3 (P < 0.001) while differences between T2 and T3 capillary results were not statistically significant, illustrating the effect of HBOT on capillary beds. Differences in venous values across the time points were not significant.
Conclusion: Venous serum glucose samples processed in an accredited laboratory may be more consistently accurate, but capillary point-of-care testing avoids delays in sample processing and provides glucose data that are of clinical relevance. The FreeStyle Optium™ Neo H glucometer is safe to use and provides a reliable measurement of blood glucose in the HBOT environment.

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


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):152–156. doi: 10.28920/dhm50.2.152-156. PMID: 32557417.

Experimental use of flow cytometry to detect bacteria viability after hyperbaric oxygen exposure: Work in progress report

Miroslav Rozloznik1,2,3, Alexandra Lochmanova1,4, Dittmar Chmelar1,5, Michal Hajek1,6, Karin Korytkova1, Monika Cisarikova1

1 Department of Biomedical Sciences, Faculty of Medicine, University of Ostrava, Czech Republic
2 DAN Europe, Slovensko, Slovakia
3 DNB consult, s.r.o, Kezmarok, Slovakia
4 Public Health Institute, Ostrava, Czech Republic
5 Czech National Anaerobic Bacteria Reference Laboratory, Faculty of Medicine, University of Ostrava, Czech Republic
6 Centre for Hyperbaric Medicine, City Hospital, Ostrava, Czech Republic

Corresponding author: Dr Miroslav Rozloznik, Department of Biomedical Sciences, Medical Faculty, University of Ostrava, Syllabova 19, Ostrava, Czech Republic
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Bacteria; Flow cytometry; Hyperbaric oxygen treatment; Hyperoxia; Wounds

Abstract
(Rozloznik M, Lochmanova A, Chmelar D, Hajek M, Korytkova K, Cisarikova M. Experimental use of flow cytometry to detect bacteria viability after hyperbaric oxygen exposure: Work in progress report. Diving and Hyperbaric Medicine. 2020 June 30;50(2):152–156. doi: 10.28920/dhm50.2.152-156. PMID: 32557417.)
Introduction: Hyperbaric oxygen treatment (HBOT), based on inhaling pure oxygen under elevated ambient pressure, is used as adjuvant intervention to promote healing in infected wounds. Despite extensive clinical evidence of beneficial effects of HBOT in soft tissue infections the mechanism of action remains to be elucidated. The aim of this study was to evaluate the use of flow cytometry as a novel method to assess the viability of pathogenic bacteria after hyperbaric oxygen (HBO) exposure.
Methods: Bacterial strains associated with soft tissues infections: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus were exposed to oxygen at 2.8 atmospheres absolute (atm abs) (283.6 kPa) pressure for 45, 90, or 120 min, then stained with propidium iodide and thiazole orange and analysed by flow cytometry.
Results: Escherichia coli and Staphylococcus aureus showed no change in viability, nor morphology, the viability of Pseudomonas aeruginosa reduced in a dose-dependent manner and Klebsiella pneumoniae also showed dye uptake after HBO.
Conclusions: These initial results, indicate diverse sensitivity of bacteria to HBO, and suggest that flow cytometry can be used to monitor viability and morphological changes triggered by HBO exposure in bacteria.

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: Short communication


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):157–163. doi: 10.28920/dhm50.2.157-163. PMID: 32557418.

Assessment of a dive incident using heart rate variability

André Zenske1, Andreas Koch2, Wataru Kähler2, Kerstin Oellrich2, Clark Pepper3, Thomas Muth4, Jochen D Schipke5

1 Klinikum St. Elisabeth, Straubing, Germany
2 German Naval Medical Institute, Maritime Medicine, Kiel, Germany
3 Johanna Etienne Hospital, Dept. of Anaesthesiology, Neuss, Germany
4 Institute of Occupational, Social and Environmental Medicine, Heinrich Heine University, Düsseldorf, Germany
5 Forschungsgruppe Experimentelle Chirurgie, Universitäts-Klinikum, Düsseldorf, Germany

Corresponding author: Professor Jochen D Schipke, c/o Forschungsgruppe Experimentelle Chirurgie, Universitäts-Klinikum Düsseldorf, DE, Moorenstrasse 5, D-40225 Düsseldorf
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Diving; Incident; Holter monitor; ECG; Autonomic nervous system; Heart rate variability

Abstract
(Zenske A, Koch A, Kähler W, Oellrich K, Pepper C, Muth T, Schipke JD. Assessment of a dive incident using heart rate variability. Diving and Hyperbaric Medicine. 2020 June 30;50(2):157–163. doi: 10.28920/dhm50.2.157-163. PMID: 32557418.)
Introduction: Scuba diving likely has an impact on the autonomic nervous system (ANS). In the course of conducting trials of underwater ECG recording for measurement of heart rate variability, there was an unexpected stressful event; one participant’s regulator iced and began to free-flow.
Methods: A custom-made, water- and pressure-tight aluminum housing was used to protect a portable Holter monitor. ECGs were recorded in three experienced divers who witnessed an unplanned moderately stressful incident during diving. The ECG signals were analysed for measures of heart rate variability (HRV).
Results: Analysis for different short-term HRV measures provided consistent results if periods of interest were appropriately time-aligned. There was improvement in sympatho-vagal balance. One diver unexpectedly exhibited an increase in both sympathetic and vagal activity shortly after the incident.
Conclusions: A conventional open-water dive affected the ANS of experienced recreational divers as measured by HRV which provides a global evaluation of the ANS and alterations in its two branches. The heart rate variability data gathered from several participating divers around the time of this event illustrate the potential utility of this variable in quantifying stress during diving. HRV data may be useful in addressing relevant diving related questions such as effects of cold, exercise or different breathing gases on ANS function.

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: Short communication


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):164–167. doi: 10.28920/dhm50.2.164-167. PMID: 32557419.

Adult attention-deficit/hyperactivity disorder prevalence among commercial divers in South Africa

Charles H Van Wijk1,2, WA Jack Meintjes2

1 Institute for Maritime Medicine, Simon’s Town, South Africa
2 Division of Health Systems and Public Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa

Corresponding author: Dr Charles H Van Wijk, PO Box 494, Simon’s Town 7995, South Africa
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Epidemiology; Fitness to dive; Mental health; Occupational diving; Psychology

Abstract
(Van Wijk CH, Meintjes WAJ. Adult attention-deficit/hyperactivity disorder prevalence among commercial divers in South Africa. Diving and Hyperbaric Medicine. 2020 June 30;50(2):164–167. doi: 10.28920/dhm50.2.164-167. PMID: 32557419.)
Introduction: Adult attention-deficit/hyperactivity disorder (ADHD) is associated with increased chance of workplace accidents, psychiatric comorbidities, other risky behaviours and sophisticated psychopharmacological treatment. These factors all contribute to a potentially complex risk profile within the commercial diving context. In order to make informed decisions regarding ADHD and commercial diving, further description of this condition among commercial divers is required. This paper reports on a study that aimed to determine the prevalence of adult ADHD among commercial divers.
Methods: The study used a self-reporting survey-type questionnaire to determine likely diagnosis, based on Diagnostic and Statistical Manual of Mental Disorders, 5th ed. criteria, in a group of 245 commercial divers in South Africa.
Results: Fourteen cases (5.7% of the sample) met criteria for ADHD. The majority of the cases presented with combined type, and reflected mild forms of ADHD. Adult ADHD did not appear to occur in significantly different proportions across the biographical variables of age, education or diving qualification.
Conclusion: Based on this small survey, adult ADHD may be over-represented in commercial diving in South Africa, compared to general workplace populations. However, ADHD may not necessarily be a contra-indication to commercial 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.

Publication Type: Short communication


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):168–172. doi: 10.28920/dhm50.2.168-172. PMID:32557420.

Sphenoid sinus mucocele as an unusual differential diagnosis in diving injuries

Bengusu Mirasoglu1, Seren Kirmizi1, Samil Aktas1

1 Underwater and Hyperbaric Medicine Department, Istanbul Faculty of Medicine, Istanbul, Turkey

Corresponding author: Dr Bengusu Mirasoglu, Istanbul Tip Fakultesi, Sualti Hekimligi ve Hiperbarik Tip Anabilim Dali, 34093 Fatih, Istanbul, Turkey
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Barotrauma; Decompression sickness; Inner ear; Hearing loss; Vertigo; Mucocele

Abstract

(Mirasoglu B, Kirmizi S, Aktas S. Sphenoid sinus mucocele as an unusual differential diagnosis in diving injuries. Diving and Hyperbaric Medicine. 2020 June 30;50(2):168–172. doi: 10.28920/dhm50.2.168-172. PMID: 32557420.)
Sphenoid sinus mucocele is a rare cystic lesion. It grows gradually and causes visual disturbances, ocular motility abnormalities and headache due to cavernous sinus compression. Sudden change in sinus cavity volume by a barotrauma may compress a mucocele and precipitate symptoms that may easily be confused with decompression sickness. A diver suffering from vertigo, nausea, blurry vision and hearing loss following uneventful dives is presented in this report. He underwent hyperbaric oxygen treatment for inner ear decompression sickness but later was diagnosed as sphenoid sinus mucocele. A high index of suspicion is necessary to capture rare conditions like mucocele in the differential diagnosis for divers with symptoms suggesting vestibulocochlear origin. To our knowledge, only one sphenoid sinus mucocele case presenting as a diving injury has been previously reported.

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 reports


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):173–177. doi: 10.28920/dhm50.2.173-177. PMID: 32557421.

Bubbles in the skin microcirculation underlying cutis marmorata in decompression sickness: Preliminary observations

Eduardo García1, Simon J Mitchell2,3

1 International Hospital, SSS Recompression Chamber Network, Diving Medicine and Internal Medicine Department, Cozumel, México
2 Department of Anaesthesiology, School of Medicine, University of Auckland, Auckland, New Zealand
3 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand

Corresponding author: Dr Eduardo García, International Hospital, 5 Sur #21-B Centro CP 77600, Cozumel, Quintana Roo, México
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Bubbles; Decompression illness; Decompression sickness; Skin; Venous gas embolism; Persistent foramen ovale; Pathology

Abstract
(García E, Mitchell SJ. Bubbles in the skin microcirculation underlying cutis marmorata in decompression sickness: Preliminary observations. Diving and Hyperbaric Medicine. 2020 June 30;50(2):173–177. doi: 10.28920/dhm50.2.173-177. PMID: 32557421.)
Introduction: The cutaneous form of decompression sickness (DCS) known as cutis marmorata is a frequent clinical presentation. Beyond a general acceptance that bubbles formed from dissolved inert gas are the primary vector of injury, there has been debate about pathophysiology. Hypotheses include: 1) local formation of bubbles in the skin or its blood vessels; 2) arterialisation of venous bubbles across a right to left shunt (RLS) with local amplification in bubble size after reaching supersaturated skin via the arterial circulation; and 3) passage of arterialised venous bubbles to the cerebral circulation with stimulation of a sympathetically mediated vasomotor response.
Methods: Four divers exhibiting cutis marmorata had the underlying tissue examined with ultrasound 4–5.5 hours after appearance of the rash. All subsequently underwent transthoracic echocardiography with bubble contrast to check for a RLS.
Results: In all cases numerous small bubbles were seen moving within the skin microvasculature. No bubbles were seen in adjacent areas of normal skin. All four divers had a large RLS.
Conclusion: This is the first report of bubbles in skin affected by cutis marmorata after diving. The finding is most compatible with pathophysiological hypotheses one and two above. The use of ultrasound will facilitate further study of this form of DCS.

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 reports


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):178–180. doi: 10.28920/dhm50.2.178-180. PMID: 32557422.

Diaphragmatic injury a hidden issue for divers following trauma: Case report

Matthew Summers1, Ian C Gawthorpe1,2

1 Hyperbaric Medicine Unit, Fiona Stanley Hospital, Fremantle, Western Australia
2 University of Notre Dame, Fremantle, Western Australia

Corresponding author: Matthew Summers, Fiona Stanley Hyperbaric Medicine Unit, 11 Robin Warren Drive 6150, Western Australia
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Diving; Trauma

Abstract

(Summers M, Gawthrope IC. Diaphragmatic injury a hidden issue for divers following trauma: Case report. Diving and Hyperbaric Medicine. 2020 June 30;50(2):178–180. doi: 10.28920/dhm50.2.178-180. PMID: 32557422.)
Occult diaphragmatic injury was uncovered in a patient who returned to scuba diving after a traumatic injury. Diaphragmatic injury can be a difficult diagnosis in the setting of trauma and a significant number of injuries are missed on the initial presentation. This has potential implications to those wishing to return to diving after trauma, and diving doctors must maintain a high degree of suspicion for such injuries.

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 reports


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):178–180. doi: 10.28920/dhm50.2.181-184. PMID: 32557423.

Clinical problem solving: Mental confusion and hypoxaemia after scuba diving

Jean-Eric Blatteau1, Jean Morin1, Romain Roffi1, Arnaud Druelle1, Fabrice Sbardella2, Olivier Castagna3

1 Department of Diving and Hyperbaric Medicine, Sainte-Anne Military Hospital, Toulon, France
2 Department of Radiology, Sainte-Anne Military hospital, Toulon, France
3 Military Institute of Biomedical Research (ERRSO), Toulon, France

Corresponding author: Professor Jean-Eric Blatteau, Service de Médecine Hyperbare et d’Expertise Plongée (SMHEP), Hôpital d’Instruction des Armées (HIA) Sainte-Anne, BP 600, 83800 Toulon cedex 9, France
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Bubbles; Decompression sickness; Differential diagnosis; Hyperbaric oxygen therapy; Respiratory symptoms; Stroke

Abstract
(Blatteau J-E, Morin J, Roffi R, Druelle A, Sbardella F, Castagna O. Clinical problem solving: Mental confusion and hypoxaemia after scuba diving. Diving and Hyperbaric Medicine. 2020 June 30;50(2):181–184. doi: 10.28920/dhm50.2.181-184. PMID: 32557423.)
Introduction: We report a case of a diving accident associating both cerebral symptoms and signs of respiratory impairment after two dives. The objective is to describe the process for obtaining the diagnosis.
Case report: A 52-year-old man experienced mental confusion associated with hypoxaemia after surfacing. All decompression procedures were fully respected. The diver had a spatio-temporal disorientation accompanied by a marked tendency to fall asleep spontaneously. He had no dyspnoea and no cough, but crepitations at both lung bases were found with oxygen saturation at 80%.
Conclusions: In this clinical case, cerebral magnetic resonance imaging and chest computed tomography scan helped to exclude other pathology that would have necessitated urgent transfer rather than urgent hyperbaric treatment. The imaging is particularly useful in case of cerebral and respiratory symptoms following scuba 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.

Publication Type: Case reports


2020 June;50(2)

Diving Hyperb Med. 2020 June 30;50(2):181–184. doi: 10.28920/dhm50.2.181-184. PMID: .

Sudden death after oxygen toxicity seizure during hyperbaric oxygen treatment: Case report

Rutger C Lalieu1,2, René D Bol Raap1, Emile FL Dubois1, Rob A van Hulst2,3

1 Hyperbaar Geneeskundig Centrum, Rijswijk, the Netherlands
2 Amsterdam University Medical Centres, Department of Anaesthesiology, Amsterdam, the Netherlands
3 Amsterdam University Medical Centres, Department of Surgery, Hyperbaric Dept., Amsterdam, the Netherlands

Corresponding author: Rutger C Lalieu, Treubstraat 5A, 2288 EG Rijswijk, the Netherlands
This email address is being protected from spambots. You need JavaScript enabled to view it.

Key words
Case reports; Deaths; Hyperbaric oxygen treatment; Obesity; Risk management; Side effects

Abstract

(Lalieu RC, Bol Raap RD, Dubois EFL, van Hulst RA. Sudden death after oxygen toxicity seizure during hyperbaric oxygen treatment: A case report. Diving and Hyperbaric Medicine. 2020 June 30;50(2):185–188. doi: 10.28920/dhm50.2.185-188. PMID: 32557424.)
Acute cerebral oxygen toxicity (ACOT) is a known side effect of hyperbaric oxygen treatment (HBOT), which can cause generalised seizures. Fortunately, it has a low incidence and is rarely harmful. Nevertheless, we present a case of a 37 year-old patient with morbid obesity who died unexpectedly after an oxygen toxicity seizure in the hyperbaric chamber. Considering possible causes, physiologic changes in obesity and obesity hypoventilation syndrome may increase the risk of ACOT. Obesity, especially in extreme cases, may hinder emergency procedures, both in- and outside of a hyperbaric chamber. Physicians in the hyperbaric field should be aware of the possibility of a fatal outcome after ACOT through the described mechanisms and take appropriate preventative measures. Basic airway management skills are strongly advised for involved physicians, especially when specialised personnel and equipment are not immediately available.

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 reports


 

Diving and Hyperbaric Medicine is indexed on MEDLINE, Science Citation Index Expanded (SciSearch®) and Embase/Scopus and complies with the International Committee of Medical Journal Editors (ICMJE) Recommendation for the Conduct, Report, Editing and Publication of Scholarly Work in Medical Journals.
Articles from 2017 are deposited in PubMed Central