Diving and Hyperbaric Medicine The Journal of the South Pacific Underwater Medicine Society and the European Underwater and Baromedical Society© Volume 49 No. 2 June 2019 Bullous disease and cerebral arterial gas embolism Does closing a PFO reduce the risk of DCS? A left ventricular assist device in the hyperbaric chamber The impact of health on professional diver attrition Serum tau as a marker of decompression stress Are hypoxia experiences for rebreather divers valuable? Nitrox vs air narcosis measured by critical flicker fusion frequency The effect of medications in diving E-ISSN 2209-1491 ABN 29 299 823 713 CONTENTS Diving and Hyperbaric Medicine Volume 49 No.2 June 2019 Editorials Obituary 77 Risk mitigation in divers with persistent foramen ovale 144 Dr John Knight FANZCA, Dip Peter Wilmshurst DHM, Captain RANR 78 The Editor's offering Original articles SPUMS notices and news 80 The effectiveness of risk mitigation interventions in divers 146 SPUMS Presidents message with persistent (patent) foramen ovale David Smart George Anderson, Douglas Ebersole, Derek Covington, Petar J Denoble 146 ANZHMG Report 88 Serum tau concentration after diving – an observational pilot 147 SPUMS 49th Annual Scientific study Meeting 2020 Anders Rosén, Nicklas Oscarsson, Andreas Kvarnström, Mikael Gennser, Göran Sandström, Kaj Blennow, Helen Seeman-Lodding, Henrik 147 Divers Emergency Service/DAN Zetterberg AP Foundation Telemedicine Scholarship 2019 96 A survey of scuba diving-related injuries and outcomes among French recreational divers 148 Australian and New Zealand David Monnot, Pierre Lafère, Thierry Michot, Emmanuel Dugrenot, College of Anaesthetists Diving François Guerrero and Hyperbaric Medicine Special 107 The impact of health on professional diver attrition Interest Group Chris Sames, Desmond F Gorman, Simon J Mitchell, Lifeng Zhou 149 SPUMS Diploma in Diving and Hyperbaric Medicine 112 The utility and safety of hypoxia experiences for rebreather divers Simon J Mitchell, Hayden M Green, Stacey A Reading, Nicholas Gant 119 Early detection of diving-related cognitive impairment of EUBS notices and news different nitrogen-oxygen gas mixtures using critical flicker fusion frequency 150 EUBS 45th Annual Scientific Pierre Lafère, Walter Hemelryck, Peter Germonpré, Lyubisa Matity, Meeting 2019 François Guerrero, Costantino Balestra 150 EUBS Elections – Member at Large 150 EUBS Website Review article 151 EUBS President's message Ole Hyldegaard 127 Systematic review on the effects of medication under 151 EUBS 46th Annual Scientific hyperbaric conditions: consequences for the diver Erik Hoencamp, Thijs TCF van Dongen, Pieter-Jan AM van Ooij, Thijs Meeting 2020 T Wingelaar, Mees L Vervelde, Dave AA Koch, Rob A van Hulst, Rigo Preliminary Announcement Hoencamp 152 Courses and meetings Technical report 137 The Hyperbaric Protective Tube: A housing for a left 153 Diving and Hyperbaric Medicine: ventricular assist device (LVAD) in a multiplace hyperbaric Instructions for Authors chamber (summary) Jacek Kot, Piotr Siondalski, Ewa Lenkiewicz Case report 141 Cerebral arterial gas embolism in a scuba diver with a primary lung bulla Céline MJ Goffinet, Graham Simpson Diving and Hyperbaric Medicine is indexed on MEDLINE, Web of Science® and Embase/Scopus Articles from 2017 are deposited in PubMed Central PURPOSES OF THE SOCIETIES To promote and facilitate the study of all aspects of underwater and hyperbaric medicine To provide information on underwater and hyperbaric medicine To publish a journal and to convene members of each Society annually at a scientific conference SOUTH PACIFIC UNDERWATER EUROPEAN UNDERWATER AND MEDICINE SOCIETY BAROMEDICAL SOCIETY OFFICE HOLDERS OFFICE HOLDERS President President David Smart [email protected] Ole Hyldegaard [email protected] President elect Vice President Neil Banham [email protected] Jean-Eric Blatteau [email protected] Past President Immediate Past President Michael Bennett [email protected] Jacek Kot [email protected] Secretary Past President Douglas Falconer [email protected] Costantino Balestra [email protected] Treasurer Honorary Secretary Soon Teoh [email protected] Peter Germonpré [email protected] Education Officer Member-at-Large 2018 David Wilkinson [email protected] Francois Guerrero [email protected] Chairman ANZHMG Member-at-Large 2017 Neil Banham [email protected] Rodrigue Pignel [email protected] Committee Members Member-at-Large 2016 Jen Coleman [email protected] Bengusu Mirasoglu [email protected] Ian Gawthrope [email protected] Liaison Officer Cathy Meehan [email protected] Phil Bryson [email protected] Peter Smith [email protected] Webmaster Greg van der Hulst [email protected] Peter Germonpré [email protected] Webmaster ADMINISTRATION and MEMBERSHIP Joel Hissink [email protected] Membership Secretary and Treasurer ADMINISTRATION and MEMBERSHIP Kathleen Pye [email protected] Membership For further information on EUBS and to complete a membership Steve Goble [email protected] application, go to the Society’s website: www.eubs.org For further information on SPUMS and to register to become a The official address for EUBS is: member, go to the Society’s website: www.spums.org.au c/o Mrs Kathleen Pye, Membership Secretary and Treasurer The official address for SPUMS is: 35 Sutherland Crescent, Abernethy, c/o Australian and New Zealand College of Anaesthetists, Perth, Perthshire PH2 9GA, United Kingdom 630 St Kilda Road, Melbourne, Victoria 3004, Australia EUBS is a UK Registered Charity No. 264970 SPUMS is incorporated in Victoria A0020660B DIVING AND HYPERBARIC MEDICINE www.dhmjournal.com Editor Editorial Board Simon Mitchell [email protected] Michael Bennett, Australia European (Deputy) Editor David Doolette, USA Lesley Blogg [email protected] Christopher Edge, United Kingdom Associate Editor Ingrid Eftedal, Norway Michael Davis [email protected] Peter Germonpré, Belgium Editorial Assistant Jacek Kot, Poland Nicky Telles [email protected] Claus-Martin Muth, Germany Neal Pollock, Canada Submissions: https://www.manuscriptmanager.net/dhm Monica Rocco, Italy Martin Sayer, United Kingdom Subscriptions and print copies of back issues to 2017: Erika Schagatay, Sweden Steve Goble [email protected] David Smart, Australia Robert van Hulst, The Netherlands Diving and Hyperbaric Medicine is published online jointly by the South Pacific Underwater Medicine Society and the European Underwater and Baromedical Society E-ISSN 2209-1491; ABN 29 299 823 713 Diving and Hyperbaric Medicine Volume 49 No. 2 June 2019 77 Editorial Risk mitigation in divers with persistent (patent) foramen ovale In this issue, Anderson and colleagues report follow-up of Randomisation to the treatment groups was not possible divers who were found to have a persistent (patent) foramen and its absence results in imbalance. Because the closure ovale (PFO) or, in eleven cases, an atrial septal defect group is approximately twice as large as the conservative (ASD).1 In most divers diagnosis followed an episode of group, similar changes in incidence would have a greater decompression illness (DCI). The efficacy of closure of the probability of achieving statistical significance in the former. PFO/ASD in preventing future DCI was compared with Large shunts were present in more than three-quarters of conservative diving. They reported that in the closure group the closure group but fewer than half of the conservative the occurrence of confirmed DCI decreased significantly group. The authors have three definitions of a 'large' PFO, compared with pre-closure, but in the conservative group so the definition of large was inconsistent. All ASDs were this reduction was not significant. considered to be large. It is believed there are three requirements for a diver to suffer When dealing with small numbers, one needs patient-level shunt-mediated DCI: data, but that is lacking and may mask inconsistency in • A significant right-to-left shunt (usually a large PFO management. The divers were investigated and treated in but sometimes an ASD or pulmonary arteriovenous at least 38 hospitals (some divers did not state where they malformation). were treated). We do not know what devices were used for • Venous bubbles nucleated during decompression PFO/ASD closure, and closure effectiveness varies, or what circumvent the lung filter by passing through the shunt. tests were performed to assess the effectiveness of closure.5 • Target tissues are supersaturated with dissolved inert gas, so that they are able to amplify embolic bubbles.2,3 The primary end-point was not different between the All three are required because DCI does not occur after two groups because only two episodes of confirmed DCI contrast echocardiography when bubbles cross a right-to- occurred in each group. The authors also considered a softer left shunt. and subjective end-point, possible DCI. Therefore, there are two ways that a diver who has suffered Crucially we are not told what the divers in the conservative shunt-mediated DCI may continue to dive – either their group were told constitutes a conservative dive and whether shunt is sealed or future dives should be so conservative it was consistent. Nor are we told whether they followed that venous bubbles are not liberated and/or critical tissues the advice given. That is important because it appears that are not able to amplify embolic bubbles.4 incidence