2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):209−217. doi: 10.28920/dhm48.4.209-217. PMID: 30517952.

Comparison of tissue oxygenation achieved breathing oxygen from a demand valve with four different mask configurations

Denise F Blake1,2, Melissa Crowe3, Daniel Lindsay4, Annie Brouff5, Simon J Mitchell6, Neal W Pollock7,8

1 Emergency Department, The Townsville Hospital, Townsville, Queensland, Australia
2 Marine Biology and Aquaculture, James Cook University, Townsville
3 Sport and Exercise Science, James Cook University
4 College of Public Health, Medical and Veterinary Sciences, James Cook University
5 Hyperbaric Medicine Unit, The Townsville Hospital
6 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
7 Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
8 Service de médecine hyperbare, Centre de médecine de plongée du Québec, Levis, Québec

Corresponding author: Denise F Blake, IMB 23, Emergency Department, 100 Angus Smith Drive, The Townsville Hospital, Douglas, Queensland, Australia 4814
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Key words
Decompression sickness; First aid; Masks; Medical kits; Oxygen; Transcutaneous oximetry; Scuba diving

Abstract
(Blake DF, Crowe M, Lindsay D, Brouff A, Mitchell SJ, Pollock NW. Comparison of tissue oxygenation achieved breathing oxygen from a demand valve with four different mask configurations. Diving and Hyperbaric Medicine. 2018 December 24;48(4):209–217. doi: 10.28920/dhm.48.4.209-217. PMID: 30517952.)
Introduction: High concentration normobaric oxygen (O2) is a priority in treating divers with suspected decompression illness. The effect of different O2 mask configurations on tissue oxygenation when breathing with a demand valve was evaluated.
Methods: Sixteen divers had tissue oxygen partial pressure (PtcO2) measured at six limb sites. Participants breathed O2 from a demand valve using: an intraoral mask (IOM®) with and without a nose clip (NC), a pocket face mask and an oronasal mask. In-line inspired O2 (FIO2) and nasopharyngeal FIO2 were measured. Participants provided subjective ratings of mask comfort, ease of breathing and holding in position.
Results: PtcO2 values and nasopharyngeal FIO2 (median & range) were greatest using the IOM® with NC and similar with the IOM® without NC. O2 measurements were lowest with the oronasal mask which also was rated as the most difficult to breathe from and to hold in position. The pocket face mask was reported as the most comfortable to wear. The NC was widely described as uncomfortable. The IOM® and pocket face mask were rated best for ease of breathing. The IOM® was rated as the easiest to hold in position.
Conclusion: Of the commonly available O2 masks for use with a demand valve, the IOM® with NC achieved the highest PtcO2 values. PtcO2 and nasopharyngeal FIO2 values were similar between the IOM® with and without NC. Given the reported discomfort of the NC, the IOM® without NC may be the best option.

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


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):218−223. doi: 10.28920/dhm48.4.218-223. PMID: 30517953.

Decompression illness and other injuries in a recreational dive charter operation

Marion Hubbard1, F Michael Davis2, Kate Malcolm3, Simon J Mitchell4

1 School of Medicine, Faculty of Medicine and Health Sciences, University of Auckland, Auckland, New Zealand
2 Formerly Hyperbaric Medicine Unit, Christchurch Hospital, Christchurch, New Zealand
3 Dive! Tutukaka, Tutukaka, Northland, New Zealand
4 Department of Anaesthesiology, Faculty of Medicine and Health Sciences, University of Auckland

Corresponding author: Simon Mitchell, Department of Anaesthesiology, Faculty of Medicine and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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Key words
Scuba diving; Diving at work; Diving incidents; Health surveys; Decompression sickness; Epidemiology

Abstract
(Hubbard M, Davis FM, Malcolm K, Mitchell SJ. Decompression illness and other injuries in a recreational dive charter operation. Diving and Hyperbaric Medicine. 2018 December 24;48(4):218–223. doi: 10.28920/dhm48.4.218-223. PMID: 30517953.)
Introduction: Health and safety within the recreational diving industry are poorly described. We aimed to obtain the true prevalence of decompression illness (DCI) and other diving and non-diving injuries, including occupational injuries, in a large recreational diving charter operation.
Methods: A New Zealand recreational diving operator keeps detailed records of diving activity and event/incident reports. We extracted passenger and crew numbers, dive numbers and incident statistics from all boat trips and associated work-related injuries between 01 January 2008 and 31 December 2014. The records of divers referred to the regional hyperbaric unit for suspected DCI were reviewed retrospectively. Using these data the prevalence of DCI and non-diving injuries were calculated.
Results: There were 65,536 person-trips to sea and 57,072 divers undertook 97,144 dives. Fifty-five injury events were documented over seven years, 31 in customers and 24 in staff. Four divers (including one staff member) diagnosed with DCI underwent recompression therapy, giving a prevalence of 0.41 cases requiring recompression per 10,000 dives, or one case per 24,386 dives, whilst five other divers were assessed as not having DCI. There was one cardiac-related fatality. Thirty-five non-diving injuries (mainly lacerations and minor musculoskeletal injuries) were documented in 30 people resulting in 10 consulting a general practitioner and seven presenting to the local regional hospital emergency department.
Conclusions: DCI requiring recompression was relatively rare in this supervised recreational diving operation. Minor non-diving injuries were the most common adverse event. Compared to other adventure sports, the prevalence of injury in recreational scuba diving is low.

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


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):224−228. doi: 10.28920/dhm48.4.224-228. PMID: 30517954.

Fatal shark attacks on divers in Australia, 1960–2017

John Lippmann1,2

1 Divers Alert Network Asia-Pacific Foundation, Ashburton, Victoria, Australia
2 Department of Public Health and Preventative Medicine at Monash University, Victoria

Corresponding author: John Lippmann, P O Box 384, Ashburton, Victoria 3147, Australia
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Key words
Diving; Marine animals; Diving incidents; Deaths; Injuries; Spearfishing; Snorkelling

Abstract
(Lippmann J. Fatal shark attacks on divers in Australia, 1960–2017. Diving and Hyperbaric Medicine. 2018 December 24;48(4):224–228. doi: 10.28920/dhm48.4.224-228. PMID: 30517954.)
Aim: The aim of this study was to identify the number, location and characteristics associated with fatal shark attacks on divers in Australian waters from 1960 to 2017, inclusive.
Methods: Searches were made of the Divers Alert Network Asia-Pacific Diving Mortality Database; the International Shark Attack File website; the Australian Shark Attack File and the Global Shark Attack File to identify cases of fatal shark attacks on divers in Australia. In addition, a systematic search of published medical and sporting literature was conducted to identify relevant reports. The data collected were scrutinised for relevance and duplication.
Results: There were 187 recorded attacks on divers, comprising 112 snorkellers, 62 scuba divers and 13 on divers using surface-supplied breathing apparatus. These included 28 verified deaths: 13 involving snorkellers, eight involving scuba divers, and seven divers using surface-supply. The victims’ ages ranged from 13−50 years (mean 31 years). All but three were males. The vast majority of attacks were by Carcharodon carcharias (Great White Shark).
Conclusion: Spearfishing and other seafood collection, as well as diving near fishing activities and/or seals, were identified as major risk factors. However, shark attacks on divers are relatively rare and represent only 3% of diving-related fatalities in Australia over this 57-year period.

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

Publication Type: Original article


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):229−234. doi: 10.28920/dhm48.4.229-234. PMID: 30517955.

Assessment of hyperbaric patients at risk of malnutrition using the Malnutrition Screening Tool – a pilot study

Hooi Geok See1, Yan Ru Tan1, Kwan Leong Au-Yeung2, Michael H Bennett3

1 Division of Anaesthesiology and Perioperative Medicine, Singapore General Hospital, Singapore
2 Department of Accident and Emergency, Queen Elizabeth Hospital, Hong Kong
3 Department of Diving and Hyperbaric Medicine, Prince of Wales Hospital, Sydney, Australia

Corresponding author: Hooi Geok See, Block 6 Level 2, Anaesthesiology Office, Singapore General Hospital, Outram Road, Singapore 169608
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Key words
Chronic wounds; Hyperbaric oxygen therapy; Nutrition assessment; Outpatients; Prevalence

Abstract
(See HG, Tan YR, Au-Yeung KL, Bennett MH. Assessment of hyperbaric patients at risk of malnutrition using the Malnutrition Screening Tool: a pilot study. Diving and Hyperbaric Medicine. 2018 December 24;48(4);229–234. doi: 10.28920/dhm48.4.229-234. PMID: 30517955.)
Background: Nutritional assessment and support is essential for wound management. The hyperbaric oxygen clinic is a unique outpatient service where chronically unwell patients present daily for hyperbaric oxygen treatment (HBOT) over several weeks, allowing time for effective nutritional intervention. This is the first study to examine the prevalence of those at risk of malnutrition in a cohort of hyperbaric medical patients.
Methods: A prospective study was undertaken over six months. Following consent, 39 enrolled patients had the Malnutrition Screening Tool and Baseline Characteristic Collection Form completed. Those at risk of malnutrition were given an option to be assessed by a dietitian to complete a Subjective Global Assessment (SGA). At the completion of treatment, the patients completed a questionnaire.
Results: Twelve of the 39 patients screened were at risk of malnutrition using our screening process. Of these, all the patients with available SGA results were diagnosed with moderate to severe malnutrition. Patients receiving HBOT for non-healing wounds and osteoradionecrosis were most at risk of malnutrition.
Conclusion: The prevalence of patients being at risk of malnutrition in our hyperbaric medical service was about one in three. Malnutrition screening should be part of routine patient assessment in order to ensure patients receive timely nutritional intervention. This may improve wound healing.

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

Publication Type: Original article


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):235−240. doi: 10.28920/dhm48.4.235-240. PMID: 30517956.

Preventive effects of ketone ester BD-AcAc2 on central nervous system oxygen toxicity and concomitant acute lung injury

Hongjie Yi1, Shichong Yu2, Yanan Zhang1, Runping Li1, Dazhi Zhang2, Weigang Xu1

1 Department of Diving and Hyperbaric Medicine, Naval Medical University, Shanghai, P R China
2 Department of Organic Chemistry, Naval Medical University, Shanghai

Corresponding author: Weigang Xu, Department of Diving and Hyperbaric Medicine, Naval Medical University, Shanghai 200433, China
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Key words
Hyperbaric oxygen; Hyperoxia; Injuries; Respiratory; Animal model; Pharmacology

Abstract
(Yi H, Yu S, Zhang Y, Li R, Zhang D, Xu W. Preventive effects of ketone ester BD-AcAc2 on central nervous system oxygen toxicity and concomitant acute lung injury. Diving and Hyperbaric Medicine. 2018 December 24;48(4):235–240. doi: 10.28920/dhm48.4.235-240. PMID: 30517956.)
Background: Recent studies indicated that ketone ester R,S-1,3-butanediol acetoacetate diester (BD-AcAc2) may be effective in preventing central nervous system oxygen toxicity (CNS-OT) and concomitant acute lung injury, a serious medical problem to be faced when breathing hyperbaric oxygen (HBO). This study aimed to further investigate the protective effects of BD-AcAc2 against CNS-OT and concomitant acute lung injury (ALI) in mice.
Methods: Mice were treated with BD-AcAc2 in peanut oil vehicle (2.5, 5.0 or 10.0 g·kg-2 body weight) by gavage 20 minutes before 600 kPa HBO exposure. Control mice received the vehicle only. Seizure latency was recorded. Malondialdehyde content in brain and lung tissues, total protein level in bronchoalveolar lavage fluid (BLF) and lung water content were measured 60 minutes after the hyperbaric exposure. Histopathology of lung tissue was undertaken.
Results: Compared with the vehicle alone, BD-AcAc2 prolonged seizure latency in a dose-dependent manner (P < 0.01). The HBO-induced increase in brain malondialdehyde, BLF protein and lung water were significantly reduced by BD-AcAc2 (P < 0.01).
Conclusion: Oral administration of the ketone ester BD-AcAc2 significantly protected against CNS-OT and concomitant ALI. Alleviation of oxidative stress may be one underlying mechanism providing this effect.

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

Publication Type: Original article


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):241−251. doi: 10.28920/dhm48.4.241-251. PMID: 30517957.

Vibration and bubbles: a systematic review of the effects of helicopter retrieval on injured divers

Denise F Blake1,2, Melissa Crowe3, Simon J Mitchell4, Peter Aitken5,6, Neal W Pollock7,8

1 Emergency Department, The Townsville Hospital, Townsville, Queensland, Australia
2 Marine Biology and Aquaculture, James Cook University, Townsville
3 Discipline of Sport and Exercise Science, James Cook University, Townsville
4 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
5 College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville
6 Health Disaster Management Unit, Queensland Health, Brisbane, Queensland
7 Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
8 Service de médecine hyperbare, Centre de médecine de plongée du Québec, Levis, Québec

Corresponding author: Denise F Blake, IMB 23, Emergency Department, 100 Angus Smith Drive, The Townsville Hospital, Douglas, Queensland, Australia, 4814
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Key words
Transport; Scuba diving; Decompression sickness; Venous gas embolism (VGE); Vibration; Review article

Abstract
(Blake DF, Crowe M, Mitchell SJ, Aitken P, Pollock NW. Vibration and bubbles: a systematic review of the effects of helicopter retrieval on injured divers. Diving and Hyperbaric Medicine. 2018 December 24;48(4):241−251. doi: 10.28920/dhm48.4.241-251. PMID: 30517957.)
Introduction: Vibration from a helicopter during aeromedical retrieval of divers may increase venous gas emboli (VGE) production, evolution or distribution, potentially worsening the patient’s condition.
Aim: To review the literature surrounding the helicopter transport of injured divers and establish if vibration contributes to increased VGE.
Method: A systematic literature search of key databases was conducted to identify articles investigating vibration and bubbles during helicopter retrieval of divers. Level of evidence was graded using the Oxford Centre for Evidence-Based Medicine guidelines. A modified quality assessment tool for studies with diverse designs (QATSDD) was used to assess the overall quality of evidence.
Results: Seven studies were included in the review. An in vitro research paper provided some evidence of bubble formation with gas supersaturation and vibration. Only one prospective intervention study was identified which examined the effect of vibration on VGE formation. Bubble duration was used to quantify VGE load with no difference found between the vibration and non-vibration time periods. This study was published in 1980 and technological advances since that time suggest cautious interpretation of the results. The remaining studies were retrospective chart reviews of helicopter retrieval of divers. Mode of transport, altitude exposure, oxygen and intravenous fluids use were examined.
Conclusion: There is some physical evidence that vibration leads to bubble formation although there is a paucity of research on the specific effects of helicopter vibration and VGE in divers. Technological advances have led to improved assessment of VGE in divers and will aid in further research.

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

Publication Type: Review article


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):252−258. doi: 10.28920/dhm48.4.252-258. PMID: 30517958.

Validation of algorithms used in commercial off-the-shelf dive computers

Doug Fraedrich1

1 Washington DC, USA

Corresponding author: Doug Fraedrich, 31 D St NW, Washington DC 2004, USA
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Key words
Decompression; Decompression sickness; Deep diving; Computers-diving; Simulation

Abstract
(Fraedrich D. Validation of algorithms used in commercial off-the-shelf dive computers. Diving and Hyperbaric Medicine. 2018 December 24;48(4):252–258. doi: 10.28920/dhm48.4.252-258. PMID: 30517958.)
Introduction: Whilst the US Navy has been very systematic about validating Navy dive computer algorithms, there has been little documented or published evidence of rigorous testing of the algorithms in commercial off-the-shelf dive computers. This paper reports the evaluation of four algorithms used in these − Bühlmann ZHL-16C; VPM-B; Suunto-RGBM; EMC-20H − by comparison with US Navy experimental dives with known decompression sickness outcomes.
Methods: Three specific tests were developed to test the algorithms’ ability to mitigate decompression sickness: Total decompression time; no stop times and first stop depth. Output of commercial decompression algorithms were compared to either the probability of decompression sickness (PDCS) results from US Navy man-trials or statistical models derived from PDCS data. The algorithms were first tested with default conservative factors, then these factors were adjusted if the tests were not initially passed. The last verification step was to compare the output of the wrist computer with that of the full desktop algorithm.
Results: This testing indicated that, whilst none of the four passed all of the proposed tests with factory-default conservatism, ZHL-16C and Suunto-RGBM could be made to pass by adjusting user-defined settings.
Conclusions: Man-trial data on PDCS is available to the non-US Navy scientific community for testing of commercial decompression algorithms. This type of validation testing can be very informative on how to best use available commercial dive computers to improve diver safety.

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

Publication Type: Technical report


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):259−261. doi: 10.28920/dhm48.4.259-261. PMID: 30517959.

A diver with immersion pulmonary oedema and prolonged respiratory symptoms

Ryo Morishima1,2,3, Kei Nakashima2, Shinya Suzuki4, Nobuo Yamami5, Masahiro Aoshima2

1 Department of Neurology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyo, Japan
2 Department of Pulmonary Medicine, Kameda Medical Centre, Kamogawa, Chiba, Japan
3 Department of Medicine, Awa Regional Medical Centre, Tateyama, Chiba
4 Department of Emergency Medicine, Kameda Medical Centre
5 Yamami Clinic, Nichinan, Miyazaki, Japan

Corresponding author: Ryo Morishima, 183-0042 Musashidai 2-6-1, Fuchu city, Tokyo, 183-0042, Japan
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Key words
Ascent; Barotrauma; Breath-hold diving; Scuba diving; Hyperbaric oxygen therapy; Inflammation; Case reports

Abstract

(Morishima R, Nakashima K, Suzuki S, Yamami N, Aoshima M. A diver with immersion pulmonary oedema and prolonged respiratory symptoms. Diving and Hyperbaric Medicine. 2018 December 24;48(4):259−261. doi: 10.28920/dhm48.3.259-261. PMID: 30517959.)
Immersion pulmonary oedema (IPE) is particularly associated with an excessive reaction to exercise and/or cold stress. IPE usually resolves without recompression therapy within a day or two. Herein we report a diver diagnosed with IPE, in whom symptoms persisted for five days. A 58-year-old man presented with sudden onset of dyspnoea, cough and haemoptysis after surfacing. He was an experienced diving instructor with a history of moderate mitral valve regurgitation. While IPE was diagnosed and oxygen administered, respiratory symptoms deteriorated, and serum C-reactive protein elevated. No evidence of infection was seen. Three hyperbaric oxygen treatments were given on the basis of suspected decompression sickness, and symptoms subsequently resolved. The recently diagnosed mitral valve regurgitation and inflammatory response were considered to have contributed to the prolongation of symptoms.

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

Publication Type: Case report


2018 December;48(4)

Diving Hyperb Med. 2018 December;48(4):262−263. doi: 10.28920/dhm48.4.262-263. PMID: 30517960.

The on-site differential diagnosis of decompression sickness from endogenous cerebral ischaemia in an elderly Ama diver using ultrasound

Youichi Yanagawa, Kazuhiko Omori, Ikuto Takeuchi, Kei Jitsuiki, Hiromichi Ohsaka, Kouhei Ishikawa

 

Department of Acute Critical Care Medicine, Juntendo Shizuoka Hospital, Izunokuni City, Shizuoka Prefecture, Japan

Corresponding author: Youchi Yanagawa, 1129 Nagaoka, Izunokuni City, Shizuoka, Japan 410-2295
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Key words
Breath-hold diving; Indigenous divers; Stroke; Doppler; Case reports

Abstract

(Yanagawa Y, Omori K, Takeuchi I, Jitsuiki K, Ohsaka H, Ishikawa K. The on-site differential diagnosis of decompression sickness from endogenous cerebral ischaemia in an elderly Ama diver using ultrasound. Diving and Hyperbaric Medicine. 2018 December 24;48(4):262−263. doi: 10 28920/dhm48.4.262-263. PMID: 30517960.)
Commercial or occupational breath-hold (BH) harvest divers along the coast and islands of Japan are collectively called Ama divers. Repetitive BH diving by Ama divers may place them at risk of developing neurological decompression sickness (DCS). We report a 74-year-old Ama diver who demonstrated right hemiparesis during an ascent after free diving at a depth of 5 metres' sea water. This report suggests the usefulness of on-site ultrasound for making a differential diagnosis of DCS from endogenous cerebral ischaemia. Further clinical studies of this management approach are warranted.

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

Publication Type: Case report


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Articles from 2017 are deposited in PubMed Central

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