2017 September;47(3)
Diving Hyperb Med. 2017 September;47(3):144-154. doi: 10.28920/dhm47.3.144-154. PMID: 28868594. PMCID: PMC6159623.
Chain of events analysis for a scuba diving fatality
John Lippmann1,2, Christopher Stevenson2, David McD Taylor3,4, Jo Williams2, Mohammadreza Mohebbi5
1 Divers Alert Network (DAN) Asia-Pacific, Ashburton, Victoria, Australia
2 School of Health and Social Development, Deakin University, Geelong, Victoria, Australia
3 Emergency Department, Austin Hospital, Victoria, Australia
4 Department of Medicine, University of Melbourne, Australia
5 Biostatistics Unit, Deakin University, Geelong, Victoria, Australia
Corresponding author: John Lippmann, Divers Alert Network (DAN) Asia-Pacific, PO Box 384, Ashburton, Victoria 3147, Australia
Key words
Scuba diving; Incidents; Deaths; Investigations; Analysis; Epidemiology
Abstract
(Lippmann J, Stevenson C, Taylor D McD, Williams J, Mohebbi M. Chain of events analysis for a scuba diving fatality. Diving and Hyperbaric Medicine. 2017 September;47(3):144-154. doi: 10.28920/dhm47.3.144-154. PMID: 28868594. PMCID: PMC6159623.)
Introduction: A scuba diving fatality usually involves a series of related events culminating in death. Several studies have utilised a chain of events-type analysis (CEA) to isolate and better understand the accident sequence in order to facilitate the creation of relevant countermeasures. The aim of this research was to further develop and better define a process for performing a CEA to reduce potential subjectivity and increase consistency between analysts.
Methodology: To develop more comprehensive and better-defined criteria, existing criteria were modified and a template was created and tested using a CEA. Modifications comprised addition of a category for pre-disposing factors, expansion of criteria for the triggers and disabling agents present during the incident, and more specific inclusion criteria to better encompass a dataset of 56 fatalities. Four investigators (raters) used both the previous criteria and this template, in randomlyassigned order, to examine a sample of 13 scuba diver deaths. Individual results were scored against the group consensus for the CEA. Raters’ agreement consistency was compared using the Index of Concordance and intra-class correlation coefficients (ICC).
Results: The template is presented. The index of concordance between the raters increased from 62% (194/312) using the previous criteria to 82% (257/312) with use of this template indicating a substantially higher inter-rater agreement when allocating criteria. The agreement in scoring with and without template use was also quantified by ICC which were generally graded as low, illustrating a substantial change in consistency of scoring before and after template use.
Conclusion: The template for a CEA for a scuba diving fatality improves consistency of interpretation between users and may improve comparability of diving fatality reports.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
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Diving Hyperb Med. 2017 September;47(3):155-158. doi: 10.28920/dhm47.3.155-158. PMID: 28868595. PMCID: PMC6159625.
Heat deactivation of the stonefish Synanceia horrida venom – implications for first-aid management
Samantha Barnett, Silvia Saggiomo, Michael Smout, Jamie Seymour
Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
Corresponding author: Silvia Saggiomo, Australian Institute of Tropical Health and Medicine, James Cook University, 14-88 McGregor Road, Smithfield, Cairns, Queensland 4878, Australia
Key words
Marine animals; Toxins; Envenomation; First aid; Water; Temperature; Myocytes, cardiac
Abstract
(Barnett S, Saggiomo S, Smout M, Seymour J. Heat deactivation of the stonefish Synanceia horrida venom – implications for first-aid management. Diving and Hyperbaric Medicine. 2017 September;47(3):155-158. doi: 10.28920/dhm47.3.155-158. PMID: 28868595. PMCID: PMC6159625.)
Objectives: To investigate the effects of temperature and hot water immersion time on neutralising venom lethality of the Australian estuarine stonefish (Synanceia horrida).
Design: Depths of the spines were measured while venom was extracted from S. horrida individuals. The venom was then exposed to temperatures of 4°C, 37.0°C, 40.1°C, 42.3°C, 45.0°C, 47.7°C, 55.2°C, and 60.0°C for either five or 20 minutes incubation periods. Venom samples were added to cultured human cardiomyocytes and cell viability curves were produced using the ACEA’s xCELLigence real-time cell monitoring system.
Main outcome measures: Determination of venom lethality on cardiomyocytes at a range of temperatures.
Results: The average depth of the spine required to go into a victims’ flesh before the venom gland compressed and expelled venom was 18 mm. Cardiomyocytes exposed to heat-treated venom for five minutes required higher temperatures to neutralise 99% of the venom, namely 44.6°C in comparison to 42.1°C with an incubation time of 20 minutes.
Conclusion: This study supports the use of hot water immersion therapy in the treatment of S. horrida stings. It is suggested that due to the depth of the puncture wound longer incubation times should be sought to allow heat to penetrate the deeper portions of the dermis and effectively begin venom deactivation.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
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Diving Hyperb Med. 2017 September;47(3):159-167. doi: 10.28920/dhm47.3.159-167. PMID: 28868596. PMCID: PMC6159624.
Decompressing rescue personnel during Australian submarine rescue operations
Michael P Reid1, Andrew Fock2, David J Doolette3
1 Submarine Underwater Medicine Unit, Royal Australian Navy, Sydney, Australia
2 Hyperbaric Unit, The Alfred Hospital, Melbourne, Australia
3 Navy Experimental Diving Unit, United States Navy, Panama City, USA
Corresponding author: Michael Reid, John Hunter Hospital, Department of Anaesthesia, Locked Bag 1, Hunter Region Mail Centre, NSW, 2310, Australia
Key words
Decompression tables; Decompression sickness; Probability; Models; Oxygen; Military diving; Environmental medicine
Abstract
(Reid MP, Fock A, Doolette DJ. Decompressing rescue personnel during Australian submarine rescue operations. Diving Hyperbaric Medicine. 2017 September;47(3):159-167. doi: 10.28920/dhm47.3.159-167. PMID: 28868596. PMCID: PMC6159624.)
Introduction: Personnel rescuing survivors from a pressurized, distressed Royal Australian Navy (RAN) submarine may themselves accumulate a decompression obligation, which may exceed the bottom time limits of the Defense and Civil Institute of Environmental Medicine (DCIEM) Air and In-Water Oxygen Decompression tables (DCIEM Table 1 and 2) presently used by the RAN. This study compared DCIEM Table 2 with alternative decompression tables with longer bottom times: United States Navy XVALSS_DISSUB 7, VVAL-18M and Royal Navy 14 Modified tables.
Methods: Estimated probability of decompression sickness (PDCS), the units pulmonary oxygen toxicity dose (UPTD), the volume of oxygen required and the total decompression time were calculated for hypothetical single and repetitive exposures to 253 kPa air pressure for various bottom times and prescribed decompression schedules.
Results: Compared to DCIEM Table 2, XVALSS_DISSUB 7 single and repetitive schedules had lower estimated PDCS, which came at the cost of longer oxygen decompressions. For single exposures, DCIEM schedules had PDCS estimates ranging from 1.8% to 6.4% with 0 to 101 UPTD and XVALSS_DISSUB 7 schedules had PDCS of less than 3.1%, with 36 to 350 UPTD.
Conclusions: The XVALSS_DISSUB 7 table was specifically designed for submarine rescue and, unlike DCIEM Table 2, has schedules for the estimated maximum required bottom times at 253 kPa. Adopting these tables may negate the requirement for saturation decompression of rescue personnel exceeding DCIEM limits.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
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Diving Hyperb Med. 2017 September;47(3):168-172. doi: 10.28920/dhm47.3.168-172. PMID: 28868597. PMCID: PMC6159615.
Decompressing recompression chamber attendants during Australian submarine rescue operations
Michael P Reid1, Andrew Fock2, David J Doolette3
1 Submarine Underwater Medicine Unit, Royal Australian Navy, Sydney, Australia
2 Hyperbaric Unit, The Alfred Hospital, Melbourne, Australia
3 Navy Experimental Diving Unit, United States Navy, Panama City, USA
Corresponding author: Michael Reid, John Hunter Hospital, Department of Anaesthesia, Locked Bag 1, Hunter Region Mail Centre, NSW, 2310, Australia
Key words
Decompression tables; Decompression sickness; Probability; Models; Oxygen; Military diving; Environmental medicine
Abstract
(Reid MP, Fock A, Doolette DJ. Decompressing recompression chamber attendants during Australian submarine rescue operations. Diving and Hyperbaric Medicine. 2017 September;47(3):168-172. doi: 10.28920/dhm47.3.168-172. PMID: 28868597. PMCID: PMC6159615.)
Introduction: Inside chamber attendants rescuing survivors from a pressurised, distressed submarine may themselves accumulate a decompression obligation which may exceed the limits of Defense and Civil Institute of Environmental Medicine tables presently used by the Royal Australian Navy. This study assessed the probability of decompression sickness (PDCS) for medical attendants supervising survivors undergoing oxygen-accelerated saturation decompression according to the National Oceanic and Atmospheric Administration (NOAA) 17.11 table.
Methods: Estimated probability of decompression sickness (PDCS), the units pulmonary oxygen toxicity dose (UPTD) and the volume of oxygen required were calculated for attendants breathing air during the NOAA table compared with the introduction of various periods of oxygen breathing.
Results: The PDCS in medical attendants breathing air whilst supervising survivors receiving NOAA decompression is up to 4.5%. For the longest predicted profile (830 minutes at 253 kPa) oxygen breathing at 30, 60 and 90 minutes at 132 kPa partial pressure of oxygen reduced the air-breathing-associated PDCS to less than 3.1 %, 2.1% and 1.4% respectively.
Conclusions: The probability of at least one incident of DCS among attendants, with consequent strain on resources, is high if attendants breathe air throughout their exposure. The introduction of 90 minutes of oxygen breathing greatly reduces the probability of this interruption to rescue operations.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
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Diving Hyperb Med. 2017 September;47(3):173-179. doi: 10.28920/dhm47.3.173-179. PMID: 28868598. PMCID: PMC6159611.
Turkish recreational divers: a comparative study of their demographics, diving habits, health and attitudes towards safety
Bengusu Mirasoglu, Samil Aktas
Istanbul Faculty of Medicine, Underwater and Hyperbaric Medicine Department
Corresponding author: Bengusu Mirasoglu, Istanbul Tip Fakultesi, Sualti Hekimligi ve Hiperbarik Tip Anabilim Dali, Capa/Fatih, 34093 Istanbul, Turkey
Key words
Scuba diving; Sex; Medical conditions; Decompression sickness; Menstruation; Pregnancy; Survey
Abstract
(Mirasoglu B, Aktas S. Turkish recreational divers: a comparative study of their demographics, diving habits, health and attitudes towards safety. Diving and Hyperbaric Medicine. 2017 September;47(3):173-179. doi: 10.28920/dhm47.3.173-179. PMID: 28868598. PMCID: PMC6159611.)
Introduction: In Turkey, scuba diving has become more popular and accessible in the past decade and there has been a commensurate rise in the number of certified divers. This new generation of recreational divers has not been described in detail previously. The aim of this study was to profile this group, while investigating any gender differences and making comparisons with the global diving community.
Methods: Turkish dive club members and diving forum/blog readers were invited to complete an online questionnaire investigating their demography, medical issues and diving history and habits.
Results: The questionnaire was completed by 303 female and 363 male divers. Significant differences were found between the sexes in terms of demographics, diving experience and attitudes toward safety. Previous or ongoing medical conditions were reported by 100 female divers and 141 males. Only 29% of females and 22% of males had been examined by a physician trained to conduct assessments of fitness to dive. Female divers did not report problems while diving during menstruation or while taking oral contraceptives. There was no significant difference in the occurrence of decompression sickness (DCS) and DCS-like symptoms between the sexes.
Conclusion: This is the largest study to date conducted on recreational divers in Turkey and so carries some value. It profiles their physical and behavioral attributes as well as differences in diving practices between the sexes in Turkey. Our findings should have implications for medical screening and dive training standards.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
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Diving Hyperb Med. 2017 September;47(3):180-190. doi: 10.28920/dhm47.3.180-190. PMID: 28868599. PMCID: PMC6159622.
Diving with pre-existing medical conditions
John Lippmann1,2, David McD Taylor3,4,Christopher Stevenson2, Jo Williams2, Simon J Mitchell5
1 Divers Alert Network Asia-Pacific, Ashburton, Victoria, Australia
2 School of Health and Social Development, Deakin University, Victoria, Australia
3 Emergency Department, Austin Hospital, Victoria, Australia
4 Department of Medicine, University of Melbourne, Australia
5 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
Corresponding author: John Lippmann, DAN Asia Pacific, PO Box 384, VIC 3147, Australia
Key words
Fitness to dive; Scuba divers; Cardiovascular; Diabetes; Respiratory; Asthma; Survey
Abstract
(Lippmann J, Taylor D McD, Stevenson C, Williams J, Mitchell SJ. Diving with pre-existing medical conditions. Diving and Hyperbaric Medicine. 2017 September;47(3):180-190. doi: 10.28920/dhm47.3.180-190. PMID: 28868599. PMCID: PMC6159622.)
Introduction: This is the second report based on a survey of Divers Alert Network Asia-Pacific (DAN AP) members who dive with cardiovascular and respiratory conditions and diabetes. It examines the medical management of the divers’ conditions, any diving modifications used to mitigate the risk and outcomes.
Methodology: An online cross-sectional survey was sent to 833 divers who had declared a targeted medical condition when applying for DAN AP membership between July 2009 and August 2013.
Results: Two-hundred-and-sixty-eight respondents (32%) provided sufficient information on their conditions to be included in the analyses. These included ischaemic heart disease (31), arrhythmias (20), cardiac septal defects (31), other cardiac conditions (10), hypertension (127), diabetes (25), asthma (40) and pneumothorax (5). Forty-nine per cent had sought
specialist diving medical advice about their condition and 23% reported modifying their diving practices to mitigate their risk. The cohort had completed 183,069 career dives, 57,822 of these since being diagnosed with their medical condition. There were 27 individuals who reported having decompression illness (25 of whom were subsequently diagnosed with a persistent foramen ovale), and two individuals who experienced an arrhythmia during diving.
Conclusions: Some DAN AP members are diving with medical conditions which could potentially impact the safety of their diving. A minority modified their diving practices to mitigate the risk of their condition and approximately half sought specialist diving medical advice. The incidence of diving-related problems precipitated by known and managed pre-existing health conditions seems low but further studies of larger cohorts and incorporating fatality data would be necessary to confirm this. These results are limited by the 32% response rate and potential for bias towards selection of those most careful with their health.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Original article
Full article available here.
Diving Hyperb Med. 2017 September;47(3):191-197. doi: 10.28920/dhm47.3.191-197. PMID: 28868600. PMCID: PMC6159614.
A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment
Marco Gelsomino, Theo Tsouras, Ian Millar, Andrew Fock
Hyperbaric Medicine Service, The Alfred Hospital, Melbourne, Victoria, Australia
Corresponding author: Marco Gelsomino, Kleinhüningerstrasse 177, 4057 Basel, Switzerland
Key words
Equipment; Chest tubes; Suction; Patient monitoring; Lung; Barotrauma; Pressure
Abstract
(Gelsomino M, Tsouras T, Millar I, Fock A. A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment. Diving and Hyperbaric Medicine. 2017 September;47(3):191-197. doi: 10.28920/dhm47.3.191-197. PMID: 28868600. PMCID: PMC6159614.)
Introduction: When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automatically manages these risks, whilst allowing more rapid hyperbaric pressure change rates.
Methods: The custom-made PVR device consists of a one-way pressure relief valve connected in line with a sterile micro filter selected for its specific flow capacity. The PVR device is designed for connection to the patient side sampling port of a PDU system, allowing inflow of ambient air whenever negative pressure is present, creating a small, controlled air leak which prevents excessive negative pressure. The hyperbaric performance of a Pleur-Evac A-6000 intercostal drain was assessed with and without this added device by measuring simulated IPP with an electronic pressure monitor connected at the patient end of the PDU. IPP readings were taken at 10, 15, 20 and 30 cmH2O of suction (set on the drain unit) at compression rates of 10, 30, 60, 80, 90 and 180 kPa·min-1 to a pressure of 280 kPa.
Results: At any compression rate of > 10 kPa·min-1, the negative IPP generated by the Pleur-Evac A-6000 alone was excessive and resulted in back flow through the PDU water seal. By adding the PVR device, the generated negative IPP remains within a clinically acceptable range, allowing compression rates of at least 30 kPa·min-1 with suction settings up to -20 cmH2O during all phases of hyperbaric treatment.
Conclusions: The PDU PVR device we have developed works well, minimising attendant workload and automatically avoiding the excessive negative IPPs that can otherwise occur. This device should only be used with suction.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Technical report
Full article available here.
Diving Hyperb Med. 2017 September;47(3):198-200. doi: 10.28920/dhm47.3.198-200. PMID: 28868601. PMCID: PMC6159621.
Periorbital emphysema after a wet chamber dive
Wei-Shih Tseng1,2, Hui-Chieh Lee1, Bor-Hwang Kang1,3
1 Department of Diving and Hyperbaric Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
2 Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
3 Department of Otorhinolaryngology Head and Neck Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
Corresponding author: Bor-Hwang Kang, Associate Professor and Director of Rhinology, Department of Otorhinolaryngology Head and Neck Surgery, Kaohsiung Veterans General Hospital, 386 Dazhong 1st Rd, Kaohsiung, Taiwan 81362
Key words
Barotrauma; Diving medicine; Military diving; Risk factors; Simulation; Training; Valsalva manoeuvre
Abstract
(Tseng W-S, Lee H-C, Kang B-H. Periorbital emphysema after a wet chamber dive. Diving and Hyperbaric Medicine. 2017 September;44(3):198-200. doi: 10.28920/dhm47.3.198-200. PMID: 28868601. PMCID: PMC6159621.)
Although periorbital emphysema (PE) is commonly associated with orbital fractures, it may develop without any fracture or significant trauma in circumstances such as post-surgery, infection, forceful nose blowing, sneezing, and weight lifting. We report on a healthy military diver who developed PE following a wet chamber dive. A diagnosis of PE secondary to sinus barotrauma was reached. He was treated conservatively without medication and his symptoms recovered completely within 10 days. To the best of our knowledge, only five cases of diving-related PE have been reported in the literature. Analysis of these cases and ours revealed that facial trauma, repeated forceful Valsalva manoeuvres and recent upper respiratory tract infection are probable risk factors for diving-related PE.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Case report
Full article available here.
Diving Hyperb Med. 2017 September;47(3):201-202. doi: 10.28920/dhm47.3.201-202. PMID: 28868602. PMCID: PMC6159616.
Ruptured tympanic membrane from underwater impact with an Atlantic salmon, Salmo salar
David Smart
Department of Diving and Hyperbaric Medicine, Royal Hobart Hospital and School of Medicine, and Faculty of Health Sciences, University of Tasmania, GPO Box 1061, Hobart, Tasmania 7001, Australia
Key words
Ear barotrauma; Underwater hazards; Marine animals
Abstract
(Smart D. Ruptured tympanic membrane from underwater impact with an Atlantic salmon, Salmo salar. Diving and Hyperbaric Medicine. 2017 September;47(3):201-202. doi: 10.28920/dhm47.3.201-202. PMID: 28868602. PMCID: PMC6159616.)
An unusual case of tympanic membrane rupture in a diver due to impact from an Atlantic Salmon, salmo salar is described. The diver was treated conservatively and the injury fully healed by eight weeks after which the diver successfully returned to diving. The author contends that the appearances of such traumatic perforations differ from barotrauma in divers secondary to ear clearing problems on descent.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in printed and other forms.
Publication Type: Case report
Full article available here.
Diving Hyperb Med. 2017 September;47(3):203. doi: 10.28920/dhm47.3.203. PMID: 28868603. PMCID: PMC8349729.
Proliferative retinopathy during hyperbaric oxygen treatment
Viet Tran1,2, David Smart1,2
1 Hyperbaric Medicine Unit, Royal Hobart Hospital, Tasmania, Australia
2 School of Medicine, University of Tasmania, Australia
Key words
Hyperbaric medicine; Vision; Side effects; Ophthalmology; Letters (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 printed and other forms.
Publication Type: Letter to the Editor
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