2024 September;54(3)
Diving Hyperb Med. 2024 30 September;54(3):155−161. doi: 10.28920/dhm54.3.155-161. PMID: 39288918.
Validation of necrotising infection clinical composite endpoint in a retrospective cohort of patients with necrotising soft tissue infections
Victoria Bion1, Dylan Jape2, Rachel Niesen2, Margaret Angliss3, Frank Bruscino-Raiola3, Biswadev Mitra4,5, Bridget Devaney1,4,5
1 Department of Intensive Care and Hyperbaric Medicine, Alfred Health, Melbourne, Australia
2 School of Medicine, Monash University, Melbourne, Australia
3 Plastics, Hand and Faciomaxillary Surgery Unit, Alfred Health, Melbourne, Australia
4 School of Public Health and Preventative Medicine, Monash University, Melbourne, Australia
5 Emergency and Trauma Centre, Alfred Health, Melbourne, Australia
Corresponding author: Dr Bridget Devaney, Head of Hyperbaric Medicine, Alfred Health, 55 Commercial Road, Melbourne, VIC 3004, Australia
ORCiD: 0000-0001-6521-418X
Keywords
Fournier’s gangrene; Hyperbaric research; Necrotising fasciitis; Necrotising infections; Organ dysfunction scores
Abstract
(Bion V, Jape D, Niesen R, Angliss M, Bruscino-Raiola F, Mitra B, Devaney B. Validation of necrotising infection clinical composite endpoint in a retrospective cohort of patients with necrotising soft tissue infections. Diving and Hyperbaric Medicine. 2024 30 September;54(3):155−161. doi: 10.28920/dhm54.3.155-161. PMID: 39288918.)
Introduction: Rapidly progressive necrotising soft tissue infections (NSTIs) are associated with high mortality and morbidity. Low incidence and disease heterogeneity contribute to low event rates and inadequately powered studies. The Necrotising Infections Clinical Composite Endpoint (NICCE) provides a binary outcome with which to assess interventions for NSTIs. Partly with a view towards studies of hyperbaric oxygen treatment in NSTIs we aimed to validate NICCE in a retrospective cohort of NSTI patients.
Methods: Eligible patients were admitted between 2012 and 2021 to an adult major referral hospital in Victoria, Australia with surgically confirmed NSTI. The NICCE and its constituents were assessed in the whole cohort (n = 235). The cohort was divided into two groups using the modified sequential organ failure assessment (mSOFA) score, with an admission mSOFA score ≥ 3 defined as high acuity.
Results: Baseline characteristics of the whole (n = 235), the high (n = 188) and the low acuity cohorts (n = 47) were similar. Survival rates were high (91.1%). Patients with an admission mSOFA ≥ 3 were less likely to meet NICCE criteria for ‘success’ compared to the lower acuity cohort (34.1% and 64.7% respectively). Meeting NICCE criteria was significantly associated with lower resource utilisation, measured by intensive care unit days, ventilator days, and hospital length of stay for all patients and for those with high acuity on presentation.
Conclusions: The NICCE provides greater discriminative ability than mortality alone. It accurately selects patients at high risk of adverse outcomes, thereby enhancing feasibility of trials. Adaptation of NICCE to include patient-centred outcomes could strengthen its clinical relevance.
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
Diving Hyperb Med. 2024 30 September;54(3):162−167. doi: 10.28920/dhm54.3.162-167. PMID: 39288919.
The role of hyperbaric oxygen treatment in the management of spondylodiscitis
Kübra Canarslan Demir1, Burak Turgut1, Gözde B Sariyerli Dursun1, Fatma S Konyalioğlu2, Taylan Zaman1
1 Department of Underwater and Hyperbaric Medicine, University of Health Sciences, Gulhane Training and Research Hospital, Ankara, Turkey
2 Department of Public Health, University of Health Sciences, Gulhane Training and Research Hospital, Ankara, Turkey
Corresponding author: Dr Kübra Canarslan Demir, SBÜ-Gülhane Eğitim ve Araştırma Hastanesi, Sualtı Hekimliği ve Hiperbarik Tıp Kliniği, Etlik/Ankara, Turkey
Keywords
Discitis; Osteomyelitis; Pain; Recovery of function; Safety; Visual analog scale
Abstract
(Canarslan Demir K, Turgut B, Sariyerli Dursun GB, Konyalioğlu FS, Zaman T. The role of hyperbaric oxygen treatment in the management of spondylodiscitis. Diving and Hyperbaric Medicine. 2024 30 September;54(3):162−167. doi: 10.28920/dhm54.3.162-167. PMID: 39288919.)
Introduction: This study analysed treatment outcomes in a patient cohort diagnosed with spondylodiscitis, who received adjunct hyperbaric oxygen treatment (HBOT) in addition to antibiotic therapy at our clinic. Important considerations included the timing of HBOT initiation on treatment success, and recurrence rates.
Methods: We retrospectively reviewed the records of all patients diagnosed with spondylodiscitis who received HBOT at the Underwater and Hyperbaric Medicine Clinic in Gulhane Training and Research Hospital, between 1 November 2016 and 25 October 2022. The patients received HBOT at 243.2 kPa for a total of 120 minutes per session, once daily for five days a week for a total of 30 sessions.
Results: Twenty-five patients with spondylodiscitis were evaluated before and after combination HBOT and targeted antibiotic treatment. After treatment, patients had lower median (range) visual analogue pain scores (8 [4–10] vs 3 [0–7], P < 0.001) and C-reactive protein (22.3 [4.3–79.9] mg·L-1 vs 6.8 [0.1–96.0] mg·L-1, P = 0.002) and lower mean (standard deviation) white blood cell counts (8.8 [3.5] x 109·L-1 vs 6.1 [1.6] x 109·L-1, P = 0.002). When patients were examined (median) 48 months (2–156 months) after the completion of treatment, there were no persistent cases of spondylodiscitis.
Conclusions: Combination HBOT with targeted antibiotic therapy effectively managed our cohort of patients diagnosed with spondylodiscitis. Hyperbaric oxygen treatment was safe, with no complications experienced. Moreover, HBOT may have helped to eliminate persistence and recurrence of symptoms with long term follow-up. A randomised controlled study with a larger number of patients is needed for more definitive conclusions.
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
Diving Hyperb Med. 2024 30 September;54(3):168−175. doi: 10.28920/dhm54.3.168-175. PMID: 39288920.
Methylphenidate and the risk of acute central nervous system oxygen toxicity: a rodent model and observational data in human divers
Ivan Gur1, Yehuda Arieli2, Yinnon Matsliah3
1 Rambam Medical Center, Haifa, Israel
2 Israel Naval Medical Institute, Israel Defence Force Medical Corps, Haifa, Israel
3 Department of Pediatric Neurology and Developmental Medicine, Carmel Medical Center, Haifa, Israel
Corresponding author: Dr Ivan Gur, Department of Internal Medicine C, Rambam Medical Center, 4 HaAlia Street, Haifa 3109601, Israel
Keywords
ADHD; Attention deficit hyperactivity disorder; Diving; Hyperbaric oxygen; Seizures
Abstract
(Gur I, Arieli Y, Matsliah Y. Methylphenidate and the risk of acute central nervous system oxygen toxicity: a rodent model and observational data in human divers. Diving and Hyperbaric Medicine. 2024 30 September;54(3):168−175. doi: 10.28920/dhm54.3.168-175. PMID: 39288920.)
Introduction: The effects of methylphenidate, a stimulant often prescribed for the treatment of attention-deficit/hyperactivity disorder (ADHD), on the development of central nervous system oxygen toxicity (COT) have not been experimentally evaluated.
Methods: The records of all pure-oxygen-rebreather divers evaluated at our institution from 1975–2022 were assessed. Cases of COT were defined as a new onset of tinnitus, tunnel vision, myoclonus, headache, nausea, loss of consciousness, or seizures resolving within 15 minutes from breathing normobaric air, and matched 4:1 with similar controls. Any medications issued to the diver in the preceding three months, including methylphenidate, were recorded. In the animal arm of this study, male mice were exposed to increasing doses of methylphenidate orally, with subsequent exposure to hyperbaric O2 until clinically evident seizures were recorded.
Results: Seventy-five cases of COT were identified in divers, occurring at a median of 80 (range 2–240) minutes after dive initiation at a median depth of 5 m (2–13). Hypercarbia was documented in 11 (14.7%) cases. Prescription of methylphenidate in the preceding three months was not associated with increased risk (OR 0.72, 95% CI 0.16–3.32) of COT. In mice, increasing methylphenidate exposure dose was associated with significantly longer mean COT latency time being 877 s (95% CI 711–1,043) with doses of 0 mg·kg-1; 1,312 s (95% CI 850–1,773) when given 0.75 mg·kg-1; and 1,500 s (95% CI 988–2,012) with 5 mg·kg-1 (F = 4.635, P = 0.014).
Conclusions: Observational human data did not demonstrate an association between methylphenidate and an increased risk of COT. Methylphenidate exposure in mice prolongs COT latency and may have protective effects against COT.
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
Diving Hyperb Med. 2024 30 September;54(3):176−183. doi: 10.28920/dhm54.3.176-183. PMID: 39288921.
Medical examination of divers after COVID-19 infection: a prospective, observational study using published (original and revised) guidelines for evaluation
Charlotte Sadler1, Anna Lussier1, Ian Grover1, Karen Van Hoesen1, Peter Lindholm1
1 Division of Hyperbaric Medicine and Wound Care, Department of Emergency Medicine UCSD University of California, San Diego
Corresponding author: Associate Professor Charlotte Sadler, Division of Hyperbaric Medicine and Wound Care, Department of Emergency Medicine, University of California, San Diego, San Diego, CA, USA
ORCiD: 0000-0002-3373-6597
Keywords
Diving medicine; Fitness to dive; Medicals – diving; Respiratory; Occupational diving
Abstract
(Sadler C, Lussier A, Grover I, Van Hoesen K, Lindholm P. Medical examination of divers after COVID-19 infection: a prospective, observational study using published (original and revised) guidelines for evaluation. Diving and Hyperbaric Medicine. 2024 30 September;54(3):176−183. doi: 10.28920/dhm54.3.176-183. PMID: 39288921.)
Introduction: The COVID-19 pandemic raised significant concerns about fitness to dive due to potential damage to the pulmonary and cardiovascular systems. Our group previously published guidelines (original and revised) for assessment of these divers. Here, we report a prospective, observational study to evaluate the utility of these guidelines.
Methods: Recreational, commercial, and scientific divers with a history of COVID-19 were consented and enrolled. Subjects were evaluated according to the aforementioned guidelines and followed for any additional complications or diving related injuries.
Results: One-hundred and twelve divers (56 male, 56 female, ages 19–68) were enrolled: 59 commercial, 30 scientific, 20 recreational, two unknown (not documented), one military. Cases were categorised according to two previous guidelines (‘original’ n = 23 and ‘revised’ n = 89): category 0 (n = 6), category 0.5 (n = 64), category 1 (n = 38), category 2 (n = 2), category 3 (n = 1), uncategorisable due to persistent symptoms (n = 1). One hundred divers (89.3%) were cleared to return to diving, four (3.6%) were unable to return to diving, four (3.6%) were able to return to diving with restrictions, and four (3.6%) did not complete testing. Regarding diving related complications, one diver had an episode of immersion pulmonary oedema one year later and one diver presented with decompression sickness and tested positive for COVID-19.
Conclusions: Most divers who presented for evaluation were able to return to diving safely. Abnormalities were detected in a small percentage of divers that precluded them from being cleared to dive. Guidelines were easily implemented by a variety of clinicians.
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
Diving Hyperb Med. 2024 30 September;54(3):184−187. doi: 10.28920/dhm54.3.184-187. PMID:39288922.
Retrospective analysis of challenging cases for medical examiners of diving
Inge Reus1, Erik van de Sande2,3, Rienk Rienks2,4, Thijs Wingelaar1,2
1 Royal Netherlands Navy Diving and Submarine Medical Centre, Den Helder, the Netherlands
2 Dutch Society of Diving and Hyperbaric Medicine (DSDHM), Bilthoven, the Netherlands
3 Dutch Society for Sports Medicine (VSG), Bilthoven, the Netherlands
4 CardioExpert Clinic for Sports and Occupational Cardiology, Amsterdam, the Netherlands
Corresponding author: Inge Reus, Royal Netherlands Navy Diving and Submarine Medical Centre, Den Helder, the Netherlands
ORCiD: 0009-0005-7416-1469
Keywords
Education; Fitness to dive; Medicals-diving; Recreational diving; Training
Abstract
(Reus I, van de Sande E, Rienks R, Wingelaar T. Retrospective analysis of challenging cases for medical examiners of diving. Diving and Hyperbaric Medicine. 2024 30 September;54(3):184−187. doi: 10.28920/dhm54.3.184-187. PMID:39288922.)
Introduction: Assessing a diver’s fitness to dive enhances diving safety, with medical examiners of diving (MED) being entrusted with this responsibility. However, the effectiveness of MED training in preparing physicians for this task remains underexplored. In the Netherlands, where any physician can pursue MED qualification, challenging cases can be presented to a board of experts.
Methods: This retrospective analysis included all cases presented to a board of experts in the period 2013–2023. Aside from baseline information, cases were coded using the International Classification of Diseases 11th Revision (ICD-11). Additionally, the type of advice given by the board was also recorded.
Results: A total of 291 cases could be included, 62.5% were male divers with a median age of 47 years old (interquartile range 29–55). Circulatory (20.9%), respiratory (16.2%), neurologic (14.4%), psychiatric (9.6%) and endocrine (6.5%) disease comprised more than two-thirds of all presented cases. Problems for the MED included multimorbidity, knowledge of guidelines and interpretation of diagnostic data.
Conclusions: These results could be used to improve MED courses or serve as a topic for continuing medical education for MEDs, however, further research into generalisability is required.
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
Diving Hyperb Med. 2024 30 September;54(3):188−195. doi: 10.28920/dhm54.3.188-195. PMID: 39288923.
Arterial dissection in scuba divers: a potential adverse manifestation of the physiological effects of immersion
Neal W Pollock1,2, John Lippmann3,4, John Pearn5, John Hayman6,7
1 Department of Kinesiology, Université Laval, Quebec, QC, Canada
2 CISSS Chaudière-Appalaches (CHAU-Hôtel-Dieu de Lévis), Hyperbaric Medicine Unit, Emergency Department, Lévis, QC, Canada
3 Australasian Diving Safety Foundation, VIC, Australia
4 Department of Public Health and Preventive Medicine, Monash University, Clayton, VIC, Australia
5 Queensland Children’s Hospital, South Brisbane QLD, Australia
6 Department of Clinical Pathology, The University of Melbourne, VIC, Australia
7 Menzies School of Health Research, Casuarina, NT, Australia
Corresponding author: Associate Professor Neal W Pollock, Université Laval, Quebec, QC, Canada
Keywords
Dissecting aneurysm; Dissecting aortic aneurysm; Dissecting coronary artery; Diving; Immersion; Mammalian dive response; Osteogenesis imperfecta
Abstract
(Pollock NW, Lippmann J, Pearn J, Hayman J. Arterial dissection in scuba divers: a potential adverse manifestation of the physiological effects of immersion. Diving and Hyperbaric Medicine. 2024 30 September;54(3):188−195. doi: 10.28920/dhm54.3.188-195. PMID: 39288923.)
Introduction: Aortic dissections and dissections of cervical, cerebral, and coronary arteries have been previously reported in scuba divers. These incidents may be the consequence of a variety of physiological effects. We review the reported cases of arterial dissection in scuba divers and discuss potential contributing factors related to immersion and diving.
Methods: Medline, CINAHL Plus, and SPORTDiscus were searched for published reports of arterial dissection and the Australasian Diving Safety Foundation fatality database was searched for additional cases from Australia. Identified cases were recorded and scrutinised for possible contributing factors.
Results: Nineteen cases of arterial dissection, both fatal and non-fatal, were identified. These included cervical or intracranial artery dissection (n = 14), aortic dissection (n = 4), and coronary artery dissection (n = 1). There were 14 male and five female victims; mean age 44 years (SD 14, range 18–65). Contributing factors may include a combination of vasoconstriction and blood redistribution, untreated hypertension, increased pulse pressure, abnormal neck movement or positioning, constrictive and burdensome equipment, exercise, increased gas density and circuit resistance with concomitant elevated work of breathing, atheroma, and possibly the mammalian dive response.
Conclusions: Dissecting aneurysms of the aorta or cervical, cerebral, and coronary arteries should be considered as a potential complication of scuba diving. The development of aneurysms associated with scuba diving is likely multifactorial in pathogenesis. Detailed reporting is important in the evaluation of cases. The potential role of the mammalian dive response as a contributing factor requires further evaluation.
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
Diving Hyperb Med. 2024 30 September;54(3):196−203. doi: 10.28920/dhm54.3.196-203. PMID: 39288924.
Role of tympanocentesis in the prevention of middle ear barotrauma induced by fast buoyant ascent escape from 200 m underwater
Xu Liu1,2*, Hengrong Yuan3*, Jieying Peng1*, Guanghao Zhu1, Nan Wang3, Yukun Wen3, Hongliang Zheng1, Yiqun Fang3, Wei Wang1
1 Department of Otolaryngology – Head and Neck Surgery, Changhai Hospital, Naval Medical University, Shanghai, China
2 Department of Otorhinolaryngology and Head and Neck Surgery, No. 905 Hospital of PLA Navy, Shanghai, China
3 Department of Diving and Hyperbaric Medicine, Naval Medical Center, Naval Medical University, Shanghai, China
* Xu Liu, Hengrong Yuan and Jieying Peng contributed equally to this work
Corresponding authors: Professor Yiqun Fang, 880 Xiangyin Road, Yangpu District, Shanghai, China
Dr Wei Wang, 168 Changhai Road, Yangpu District, Shanghai, China 200433
ORCiD: 0000-0001-9991-9356
Keywords
Hearing loss; Submarine; Military diving; Deep diving; Rescue
Abstract
(Liu X, Yuan H, Peng J, Zhu G, Wang N, Wen Y, Zheng H, Fang Y, Wang W. Role of tympanocentesis in the prevention of middle ear barotrauma induced by fast buoyant ascent escape from 200 m underwater. Diving and Hyperbaric Medicine. 2024 30 September;54(3):196−203. doi: 10.28920/dhm54.3.196-203. PMID: 39288924.)
Introduction: We aimed to study middle ear barotrauma caused by fast compression followed by buoyant ascent escape from 200 m underwater and its effect on the auditory system, and to validate the preventive effect of tympanocentesis on middle ear barotrauma.
Methods: Twenty Sprague Dawley rats were divided into two groups: rats in group A underwent a simulated fast buoyant ascent escape from a depth of 200 m, while those in group B underwent tympanocentesis before the procedure described for group A. Ear endoscopy, acoustic conductance, and auditory brainstem response (ABR) tests were conducted before and after the procedure to evaluate the severity of middle ear barotrauma and auditory function in both groups. Additionally, histopathological examination of the middle ear in both groups was conducted to evaluate the severity of middle ear barotrauma by observing submucosal haemorrhage.
Results: None of the ears in either group showed any abnormalities before the experiment. In group A, middle ear barotrauma was universally observed after the simulation procedure. The tympanograms of all ears were initially type A and became type B after the procedure. Further, after the simulation, the hearing thresholds at different frequencies (4, 8, 16, 24, and
32 kHz) assessed by ABR significantly increased compared to those before the procedure. In group B, no middle ear barotrauma was observed, and the hearing threshold at each frequency did not change significantly compared with post-puncturing. After dissecting the middle ear, gross pathological observations were consistent with the above results. Microscopically, blood accumulation and submucosal haemorrhage in the middle ear cavity were observed in group A but not in group B.
Conclusions: Fast buoyant ascent from 200 m underwater can cause middle ear barotrauma, resulting in hearing loss. Tympanic membrane puncture can effectively prevent middle ear barotrauma caused by the rapid buoyant ascent escape procedure.
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
Diving Hyperb Med. 2024 30 September;54(3):204−211. doi: 10.28920/dhm54.3.204-211. PMID: 39288925.
Acoustic emission, an innovative diagnosis tool for therapeutic hyperbaric chambers: or how to requalify safely using pneumatic pressure test
Johann Catty1, Olivier Seguin2, Jean-Laurent Juillie2, Daniel Mathieu2, Erika Parmentier-Decrucq2
1 CETIM, F-60304 Senlis Cedex, France
2 Intensive Care Unit and Hyperbaric Center, Lille University Hospital, F-59037 Lille Cedex, France
Corresponding author: Johann Catty, CETIM, Pôle MCO, 52 Avenue Félix Louat, F-60304 Senlis Cedex, France
ORCiD: 0009-0006-4853-2825
Keywords
Bioengineering; Equipment; Hyperbaric facilities; Hyperbaric oxygen treatment; Therapeutic hyperbaric chamber; Requalification
Abstract
(Catty J, Seguin O, Juillie J-L, Mathieu D, Parmentier-Decrucq E. Acoustic emission, an innovative diagnosis tool for therapeutic hyperbaric chambers: or how to requalify safely using pneumatic pressure test. Diving and Hyperbaric Medicine. 2024 30 September;54(3):204−211. doi: 10.28920/dhm54.3.204-211. PMID: 39288925.)
Therapeutic hyperbaric chambers require continuous monitoring and maintenance, including periodic requalification. The primary aim is to verify the suitability for continued safe service. Maintenance is regulated in Europe, and in France requalification is mandatory where a hyperbaric chamber operates above pressures equal to or greater than 4 bar gauge. French requalification requires a hydraulic (hydrostatic) pressure test to determine the absence of deformation and leaks during the test. However, in such cases, it is often necessary to move the chamber if the combined mass of the chamber and water may exceed the allowable floor loading strength. In 2009, an innovative alternative to a hydraulic pressure testing was authorised in France. It consists of carrying out a pneumatic pressure test simultaneously with a non-destructive monitoring technique called ‘acoustic emission’. This can be compared to a microseismology technique, where sensors are applied to the pressure retaining boundary of the hyperbaric chamber, and signals emitted by the vessel under load are captured. These signals are analysed, prioritised, and classified, to determine the physical position of any sources (artifacts) through triangulation calculations. This technique makes it possible to assess the behaviour of the vessel very accurately in real time and, a posteriori, to assess its fitness for continued service. This technique reduces the unavailability time of the chamber to two days, compared to potentially several weeks when a hydraulic test is performed. Over and above financial considerations and availability of facilities, this technique provides a baseline of the integrity of pressure vessels and allows monitoring over time of any potential deterioration.
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
Diving Hyperb Med. 2024 30 September;54(3):212−216. doi: 10.28920/dhm54.3.212-216. PMID:39288926.
Evaluation of a new hyperbaric oxygen ventilator during pressure-controlled ventilation
Cong Wang1, Qiuhong Yu1, Yaling Liu1, Ziqi Ren1, Ying Liu1, Lianbi Xue2
1 Department of Hyperbaric Oxygen, Beijing Tiantan Hospital, Capital Medical University, A zone, No.199 Nansihuan West Road, Fengtai District, Beijing 100070, China
2 Department of Hyperbaric Oxygen, Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), No. 89 Taoyuan Road, Nanshan District, Shenzhen 518052, China
Corresponding author: Professor Lianbi Xue, Department of Hyperbaric Oxygen, Huazhong University of Science and Technology Union Shenzhen Hospital (Nanshan Hospital), No. 89 Taoyuan Road, Nanshan District, Shenzhen 518052, China
Keywords
Airway resistance; Intensive care; Intermittent positive-pressure ventilation; Respiratory mechanics
Abstract
(Wang C, Yu Q, Liu Y, Ren Z, Liu Y, Xue L. Evaluation of a new hyperbaric oxygen ventilator during pressure-controlled ventilation. Diving and Hyperbaric Medicine. 2024 30 September;54(3):212−216. doi: 10.28920/dhm54.3.212-216. PMID: 39288926.)
Introduction: The stability of a new hyperbaric ventilator (Shangrila590, Beijing Aeonmed Company, Beijing, China) at different clinically relevant pressures in a hyperbaric chamber during pressure-controlled ventilation (PCV) was investigated.
Methods: The ventilator was connected to a test lung in the multiplace hyperbaric chamber. The inspiratory pressure (PI) of the ventilator was set to 1.0, 1.5, 2.0, 2.5 and 3.0 kPa (approximately 10, 15, 20, 25 and 30 cmH2O). The compliance and resistance of the test lung were set to 200 mL·kPa-1 and 2 kPa·L-1·s-1, respectively. Experiments were conducted at 101, 203 and 284 kPa ambient pressure (1.0, 2.0 and 2.8 atmospheres absolute respectively). At each of the 5 PI values, the tidal volume (VT), peak inspiratory pressure (Ppeak) and peak inspiratory flow (Fpeak) displayed by the ventilator and the test lung were recorded for 20 cycles. Test lung data were considered the actual ventilation values. The ventilation data were compared among the three groups to evaluate the stability of the ventilator.
Results: At every PI, the Ppeak detected by the ventilator decreased slightly with increasing ambient pressure. The Fpeak values measured by the test lung decreased substantially as the ambient pressure increased. Nevertheless, the reduction in VT at 284 kPa and PI 30 cmH2O (compared to performance at 101 kPa) was comparatively small (approximately 60 ml).
Conclusions: In PCV mode this ventilator provided relatively stable VT across clinically relevant PI values to ambient pressures as high as 284 kPa. However, because Fpeak decreases at higher ambient pressure, some user adjustment might be necessary for precise VT maintenance during clinical use at higher PIs and ambient pressures.
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
Diving Hyperb Med. 2024 30 September;54(3):217−224. doi: 10.28920/dhm54.3.217-224. PMID: 39288927.
The investigation of diving accidents and fatalities
John Lippmann1,2,3, James Caruso4
1 Australasian Diving Safety Foundation, Canterbury, Victoria, Australia
2 Department of Public Health and Preventive Medicine, Monash University, Victoria, Australia
3 The Royal Lifesaving Society – Australia, Sydney, Australia
4 Denver Office of the Medical Examiner, Denver, Colorado, United States of America
Corresponding author: Dr John Lippmann, Australasian Diving Safety Foundation, PO Box 478, Canterbury VIC 3126, Australia
Keywords
Arterial gas embolism; Autopsy; Coroner; Decompression sickness; Diving deaths; Diving incidents; Investigations; Scuba
Abstract
(Lippmann J, Caruso J. The investigation of diving accidents and fatalities. Diving and Hyperbaric Medicine. 2024 30 September;54(3):217−224. doi: 10.28920/dhm54.3.217-224. PMID: 39288927.)
Diving accidents result from a variety of causes including human error, inadequate health and fitness, environmental hazards and equipment problems. They usually involve a cascade of events resulting in the diver being injured or deceased. The accuracy and usefulness of a diving accident investigation relies on well-targeted interviews, good field investigation, evidence collection and preservation, and appropriate equipment assessment. In the event of a fatality, a thorough and targeted autopsy is indicated. Investigators should have the appropriate knowledge, training, skills and support systems to perform the required tasks. Relevant investigations include the victim’s medical and diving history, the dive circumstances and likely accident scenario, management of the accident including rescue and first aid, equipment inspection and testing and a thorough postmortem examination conducted by a forensic pathologist with an awareness of the special requirements of a diving autopsy and the knowledge to correctly interpret the findings. A chain of events analysis can determine the likely accident scenario, identify shortcomings and inform countermeasures.
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
Diving Hyperb Med. 2024 30 September;54(3):225−229. doi: 10.28920/dhm54.3.225-229. PMID: 39288928.
Large lungs in divers: a risk for pulmonary barotrauma?
Robert A van Hulst1, Pieter-Jan AM van Ooij2,3
1 Department of Anesthesiology/Hyperbaric Medicine, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands
2 Royal Netherlands Navy Diving and Submarine Medical Centre, Den Helder, the Netherlands
3 Department of Pulmonology, Amsterdam University Medical Centre, Amsterdam, the Netherlands
Corresponding author: Professor Robert A van Hulst, Department of Hyperbaric Medicine, Anesthesiology, Meibergdreef 9, 1100 DD, Amsterdam, the Netherlands
ORCiD: 0009-0002-6945-5508
Keywords
Air embolism; Lung function; Risk factors; Vital capacity
Abstract
(van Hulst RA, van Ooij PJAM. Large lungs in divers: a risk for pulmonary barotrauma? Diving and Hyperbaric Medicine. 2024 30 September;54(3):225−229. doi: 10.28920/dhm54.3.225-229. PMID: 39288928.)
This retrospective study analysed a series of investigations on lung function in military divers and the importance of computed tomography (CT) scans concerning fitness to dive. We examined the incidence of blebs and bullae in a population of military divers with large lungs prompted by six cases of pulmonary barotrauma. All of these divers’ medicals were normal apart from having large lungs (FVC > 120% predicted). A subsequent survey of the database of all divers and submariners of the Royal Netherlands Navy (RNLN) found another 72 divers/submariners with large lungs who were then evaluated by a CT scan. This resulted in the identification of three further individuals with blebs and/or bullae, who were then declared unfit to dive. In total, the incidence of these lung abnormalities in this cohort was 11.5%. We discuss the possible consequences for fitness to dive with regard to the current literature on the subject, and also consider the most recent standards of reference values for pulmonary function indices. Based on our results and additional insights from other studies, we advise using the Global Lung Initiative reference values for pulmonary function, while performing high resolution CT scans only in divers with clinical indications.
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
Diving Hyperb Med. 2024 30 September;54(3):230−232. doi: 10.28920/dhm54.3.230-232. PMID: 39288929.
Maxillary sinus barotrauma with infraorbital nerve paraesthesia after breath-hold diving
Kubra Canarslan Demir1, Zeliha Yücel2
1 Department of Underwater and Hyperbaric Medicine, University of Health Sciences, Gulhane Training and Research Hospital, Ankara, Turkey
2 Department of Neurology, Karaman Training And Research Hospital, Neurology Clinic, Karaman, Turkey
Corresponding author: Dr Kubra Canarslan Demir, SBÜ-Gülhane Eğitim ve Araştırma Hastanesi, Sualtı Hekimliği ve Hiperbarik Tıp Kliniği, Etlik/Ankara, Turkey
ORCiD: 0000-0001-6911-2375
Keywords
Diving incidents; Diving medicine; Neurological manifestations; Recovery of function; Valsalva manoeuvre
Abstract
(Canarslan Demir K, Yücel Z. Maxillary sinus barotrauma with infraorbital nerve paraesthesia after breath-hold diving. Diving and Hyperbaric Medicine. 2024 30 September;54(3):230−232. doi: 10.28920/dhm54.3.230-232. PMID: 39288929.)
Barosinusitis, or sinus barotrauma, is a sinonasal injury and/or inflammation that results when the aerated spaces of the nose and sinuses are exposed to an uncompensated change in ambient pressure. We describe a 19-year-old male diver who presented to our clinic on the fourth day following a breath-hold diving session. During descent on a constant weight monofin dive at the South Cyprus World Championship he began to experience symptoms due to the inability to equalise the pressure, particularly in the Eustachian tubes and middle ear cavities. He felt pain and pressure in the upper left half of his face, left upper molars, and under his left eye at 60 metres, and he continued diving down to 74 metres. At presentation to our clinic, he still had ecchymosis under his right eye and pain in his upper right teeth, half of his face, and ear. He also described tingling in the lower left half of his nose and the left half of his upper lip. He received decongestants, B vitamins, and underwent endoscopic sinus drainage which alleviated his symptoms alleviated over time. The diver reported complete resolution of tingling, numbness, and pain after three months. It should not be forgotten that if appropriate treatment is delayed, permanent changes may occur as a result of long-term compression of the nerve, and therefore patients should be monitored closely.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Case report
Diving Hyperb Med. 2024 30 September;54(3):233−236. doi: 10.28920/dhm54.3.233-236. PMID: 39288930.
Lateral ST-elevation myocardial infarction from systemic air embolism after CT guided lung biopsy
Aung Myo Htay1, Emma Wilson1
1 Department of Diving and Hyperbaric Medicine, Royal Hobart Hospital, Hobart, Tasmania, Australia
Corresponding author: Dr Aung Myo Htay, Department of Diving and Hyperbaric Medicine, Royal Hobart Hospital, 48 Liverpool Street, Hobart, Tasmania 7000, Australia
Keywords
Arterial gas embolism; Cardiac; Coronary; Iatrogenic; Complications and management
Abstract
(Htay AM, Wilson E. Lateral ST-elevation myocardial infarction from systemic air embolism after CT guided lung biopsy. Diving and Hyperbaric Medicine. 2024 30 September;54(3):233−236. doi: 10.28920/dhm54.3.233-236. PMID: 39288930.)
Systemic air embolism is a rare but potentially life-threatening complication of computed tomography (CT)-guided lung biopsy. The largest lung biopsy audits report an incidence rate of approximately 0.061% for systemic air embolism, with a mortality rate of 0.07–0.15%. A prompt diagnosis with high index of suspicion is essential, and hyperbaric oxygen treatment (HBOT) is the definitive management. We report the case of a 44-year-old lady who developed a lateral ST elevation myocardial infarction from coronary artery air embolism following CT-guided lung biopsy for evaluation of a left lung lesion. The biopsy was performed in the right lateral decubitus position, and the patient reported chest pain after coughing during the procedure. The clinician decided to proceed, taking four biopsy samples as no pneumothorax was identified in the intraprocedural CT image. The patient was noted to have hypotension with ongoing chest pain post-procedure. Resuscitative measures were taken to stabilise her haemodynamics, and she was successfully treated with HBOT with total resolution of air embolism. She developed a left sided pneumothorax post-treatment and needed intercostal chest drain insertion. The left lung fully re-expanded, and the patient was discharged home after day two of admission.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Case report
Diving Hyperb Med. 2024 30 September;54(3):237−241. doi: 10.28920/dhm54.3.237-241. PMID: 39288931.
Bispectral index with density spectral array (BIS-DSA) monitoring in a patient with inner ear and cerebral decompression sickness
Gerald Schmitz1, Sharon Aguero1
1 Hyperbaric and Undersea Medical Service – Hospital CIMA, San Jose, Costa Rica
Corresponding author: Gerald Schmitz, Hyperbaric and Undersea Medical Service – Hospital CIMA, San Jose, Costa Rica
ORCiD: 0000-0002-1138-8456
Keywords
Brain; Cerebral blood flow; Decompression illness; Diving; Inner ear; Electroencephalography
Abstract
(Schmitz G, Aguero S. Bispectral index with density spectral array (BIS-DSA) monitoring in a patient with inner ear and cerebral decompression sickness. Diving and Hyperbaric Medicine. 2024 30 September;54(3):237−241. doi: 10.28920/dhm54.3.237-241. PMID: 39288931.)
Bispectral index with density spectral array (BIS-DSA) monitoring during hyperbaric oxygen therapy of a case with inner ear and cerebral decompression sickness is described. During the initial treatment, a particular DSA pattern was found, which resolved after four treatments. Clinical resolution of the symptoms accompanied this improvement. The particular BIS-DSA pattern described in this case is concordant with a potential hypo-perfusion of the cortex related to decompression stress. This case suggests that BIS-DSA monitoring may be an easy, cost-effective, and viable form of neuro-monitoring during hyperbaric oxygen treatment for 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: Case report
Diving Hyperb Med. 2024 30 September;54(3):242−248. doi: 10.28920/dhm54.3.242-248. PMID: 39288932.
Decompression sickness in surface decompression breathing air instead of oxygen
Jan Risberg1, Helle Midtgaard2
1 NUI, Bergen, Norway
2 Oslo University Hospital, Oslo, Norway
Corresponding author: Dr Jan Risberg. NUI, Gravdalsveien 245, 5165 Laksevåg, Bergen, Norway
Keywords
Decompression illness; Decompression tables; Diving tables; Incidents; Occupational diving
Abstract
(Risberg J, Midtgaard H. Decompression sickness in surface decompression breathing air instead of oxygen. Diving and Hyperbaric Medicine. 2024 30 September;54(3):242−248. doi: 10.28920/dhm54.3.242-248. PMID: 39288932.)
We report an unusual decompression sickness (DCS) incident in a commercial diving project. Eleven divers completed 91 dives to 23.5–36.2 m with bottom times ranging 23–67 min. The divers were breathing compressed air while immersed. Decompression was planned as surface decompression in a deck decompression chamber breathing oxygen typically for 15–30 min. Due to a technical error the divers breathed air rather than oxygen during the surface decompression procedure. Two divers suffered DCS. Both were recompressed on site with the same error resulting in them breathing compressed air rather than oxygen. One of them experienced a severe relapse with cardiovascular decompensation following recompression treatment. While DCS was expected due to the erroneous decompression procedures, it is noteworthy that only two incidents occurred during 91 dives with surface decompression breathing air instead of oxygen. Accounting for this error, the median omitted decompression time was 17 min (range 0–26 min) according to the Bühlmann ZHL-16C algorithm. These observations suggest that moderate omission of decompression time has a relatively small effect on DCS incidence rate. The other nine divers were interviewed in the weeks following completion of the project. None of them reported symptoms at the time, but five divers reported having experienced minor symptoms compatible with mild DCS during the project which was not reported until later.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Case report
Diving Hyperb Med. 2024 30 September;54(3):249−251. doi: 10.28920/dhm54.3.249-251. PMID: 39288933.
Hyperbaric oxygen treatment (HBOT) in a case of traumatic chondronecrosis of the cricoid cartilage
Subhranshu Kumar1, HBS Chaudhry1, Chandrasekhar Mohanty1, Sourabh Bhutani1, Muhammed Risham1, Kshitij Lanjekar1
1 Department of Marine Medicine, Institute of Naval Medicine, INHS Asvini, RC church, Colaba, Mumbai, India
Corresponding author: Dr Subhranshu Kumar, Department of Marine Medicine, Institute of Naval Medicine, INHS Asvini, RC church, Colaba, Mumbai, India
Keywords
Chronic wounds; Larynx trauma; Hyperbaric medicine; Outcome; Tracheostomy complication
Abstract
(Kumar S, Chaudhry HBS, Risham M, Lanjekar K, Mohanty C, Bhutani S. Hyperbaric oxygen treatment (HBOT) in a case of traumatic chondronecrosis of the cricoid cartilage. Diving and Hyperbaric Medicine. 2024 30 September;54(3):249−251. doi: 10.28920/dhm54.3.249-251. PMID: 39288933.)
Cricoid chondronecrosis is a rare entity and is scarcely reported in the literature. Its prevalence is increasing in the form of chondroradionecrosis among the survivorship of head and neck carcinoma patients treated with radiotherapy. We have reported a case of cricoid chondronecroisis caused by trauma from repeated tracheostomy. The patient presented with hoarseness and dyspnoea. Radiological findings in multidetector computed tomography showed disintegration of the cricoid and confirmed the diagnosis. Conservative treatment was given in the form of antibiotics, steroids and nebulised anticholinergics and bronchodilators. However, the patient did not improve and his condition worsened throughout two months of hospitalisation. He was referred for hyperbaric oxygen treatment, which was given over 30 sessions. This was associated with improvement in his condition and he was able to be decannulated from tracheostomy. Six monthly follow up of the patient showed a well-healed tracheostomy scar.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Case report
Diving Hyperb Med. 2024 30 September;54(3):252. doi: 10.28920/dhm54.3.252. PMID: 39288934.
Hyperbaric medicine and climate footprint
Alice Varichon1, Rodrigue Pignel1, Sylvain Boet1,2
1 Diving and hyperbaric Unit, Division of Emergency Medicine, Department of Anesthesiology, Clinical Pharmacology, Intensive Care and Emergency Medicine. Geneva University Hospitals and Faculty of Medicine, University of Geneva, Geneva, Switzerland
2 Hyperbaric Medicine Unit, Department of Anesthesiology and Pain Medicine, Ottawa Hospital Research Institute, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada
Corresponding author: Dr Sylvain Boet, Diving and hyperbaric Unit, Division of Emergency, Geneva University Hospital, 4 Gabrielle-Perret-Gentil Street, 1205 Geneva, Switzerland
Keywords
Climate footprint; Ecology; Hyperbaric oxygen; Hyperbaric oxygen treatment; Life cycle assessment
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Letter to the Editor