2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):318–324. doi: 10.28920/dhm50.4.318–324. PMID: 33325010.
Effects of inspiratory muscle training versus high intensity interval training on the recovery capacity after a maximal dynamic apnoea in breath-hold divers. A randomised crossover trial
Francisco de Asís-Fernández1,2, Tamara del Corral1,2, Ibai López-de-Uralde-Villanueva3
1 Departamento de Fisioterapia, Facultad de Ciencias de la Salud. Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Spain
2 Breatherapy Research Group, Instituto de Neurociencias y Ciencias del Movimiento (INCIMOV), Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Spain
3 Department of Radiology, Rehabilitation and Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, Complutense University of Madrid, Spain
Corresponding author: Professor Tamara del Corral, Departamento de Fisioterapia, Facultad de Ciencias de la Salud. Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Spain
Key words
Breath-hold diving; Apnea; Exercise; Pulmonary function; Performance; Metabolism
Abstract
(de Asís-Fernández F, del Corral T, López-de-Uralde-Villanueva I. Effects of inspiratory muscle training versus high intensity interval training on the recovery capacity after a maximal dynamic apnoea in breath-hold divers. A randomised crossover trial. Diving and Hyperbaric Medicine. 2020 December 20;50(4):318–324. doi: 10.28920/dhm50.4.318-324. PMID: 33325010.)
Introduction: After a maximal apnoea, breath-hold divers must restore O2 levels and clear CO2 and lactic acid produced. High intensity interval training (HIIT) and inspiratory muscle training (IMT) could be employed with the aim of increasing recovery capacity. This study aimed to evaluate the relative effects of IMT versus HIIT on recovery of peripheral oxygen saturation (SpO2), and also on pulmonary function, inspiratory muscle strength, lactate and heart rate recovery after a maximal dynamic apnoea in breath-hold divers.
Methods: Fifteen breath-hold divers performed two training interventions (IMT and HIIT) for 20 min, three days per week over four weeks in randomised order with a two week washout period.
Results: IMT produced a > 3 s reduction in SpO2 recovery time compared to HIIT. The forced expiratory volume in the first second (FEV1) and maximum inspiratory pressure (MIP) were significantly increased in the IMT group compared to HIIT. The magnitude of these differences in favour of IMT was large in both cases. Neither training intervention was superior to the other for heart rate recovery time, nor in peak- and recovery- lactate.
Conclusions: IMT produced a reduction in SpO2 recovery time compared to HIIT after maximal dynamic apnoea. Even a 3 s improvement in recovery could be important in scenarios like underwater hockey where repetitive apnoeas during high levels of exercise are separated by only seconds. IMT also improved FEV1 and MIP, but no differences in lactate and heart rate recovery were found post-apnoea between HIIT and IMT.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):325–331. doi: 10.28920/dhm50.4.325–331. PMID: 33325011.
Acute spontaneous spinal cord infarction: Utilisation of hyperbaric oxygen treatment, cerebrospinal fluid drainage and pentoxifylline
Catherine Ashton1, Neil Banham2, Merrilee Needham1,3,4,5
1 Neurology Department, Fiona Stanley Hospital, Murdoch, Australia
2 Department of Hyperbaric Medicine, Fiona Stanley Hospital, Murdoch, Australia
3 Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia
4 Perron Institute for Neurological and Translational Science, Nedlands, Australia
5 University of Notre Dame, Fremantle, Australia
Corresponding author: Dr Catherine Ashton, Neurology Department, Fiona Stanley Hospital, 11 Robin Warren Drive, Murdoch, WA 6150, Australia
Key words
Central nervous system; Hyperbaric oxygen treatment; Infarction; Outcome; Spinal cord; Stroke; Treatment
Abstract
(Ashton C, Banham N, Needham M. Acute spontaneous spinal cord infarction: Utilisation of hyperbaric oxygen treatment, cerebrospinal fluid drainage and pentoxifylline. Diving and Hyperbaric Medicine. 2020 December 20;50(4):325–331. doi: 10.28920/dhm50.4.325-331. PMID: 33325011.)
Introduction: Spinal cord infarction (SCI) is a potentially devastating disorder presenting with an acute anterior spinal artery syndrome, accounting for an estimated 1% of stroke presentations. Aetiologies include aortic surgical complications, systemic hypotension, fibrocartilaginous embolism and vascular malformations. Diagnosis is clinical combined with restriction on diffusion-weighted magnetic resonance imaging (MRI). There are no treatment guidelines for non-perioperative cases although there is limited literature regarding potential therapies, including hyperbaric oxygen treatment (HBOT) and cerebrospinal fluid (CSF) drainage. We describe 13 cases of acute SCI, five receiving HBOT, and three also receiving pentoxifylline and drainage of lumbar CSF.
Methods: Data for all patients with MRI-proven SCI at Fiona Stanley Hospital from 2014–2019 were reviewed.
Results: Thirteen patients, median age 57 years (31–74), 54% female, were identified. Aetiologies: two fibrocartilaginous emboli; seven likely atherosclerotic; two thromboembolic; two cryptogenic. All presented with flaccid paraplegia except one with Brown-Sequard syndrome. Levels ranged from C4 to T11. Five patients received HBOT within a median time of 40 hours from symptom onset, with an average 15 treatments (10−20). Three of these received triple therapy (HBOT, pentoxifylline, CSF drainage) and had median Medical Research Council manual muscle testing power of 5, median modified Rankin Score (mRS) of 1 and American Spinal Injury Association (ASIA) score of D on discharge, compared with 2 power, mRS 3.5 and ASIA B in those who did not.
Conclusions: SCI can be severely disabling. Triple therapy with pentoxifylline, CSF drainage and HBOT may reduce disability and further prospective trials are 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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):332–337. doi: 10.28920/dhm50.4.332-337. PMID: 33325012.
Reduction of bacterial load with the addition of ultraviolet-C disinfection inside the hyperbaric chamber
Katrina Browne1, Danielle Wood2, Kate Clezy3, Jan Lehm2, William R Walsh1
1 Surgical and Orthopaedic Research Laboratory, University of New South Wales, Prince of Wales Hospital, Sydney, Australia
2 Hyperbaric Medicine Unit, Prince of Wales Hospital, Sydney, Australia
3 Infectious Diseases Department, Prince of Wales Hospital, Sydney Australia
Corresponding author: Dr Danielle Wood, Hyperbaric Medicine Unit, Prince of Wales Hospital, Nurses Dr, Randwick, NSW 2031, Australia
Key words
Hyperbaric research; Hyperbaric facilities; Infectious disease; Bacteriology; Fire; Surveillance; Infection prevention
Abstract
(Browne K, Wood D, Clezy K, Lehm J, Walsh WR. Reduction of bacterial load with the addition of ultraviolet-C disinfection inside the hyperbaric chamber. Diving and Hyperbaric Medicine. 2020 December 20;50(4):332–337. doi: 10.28920/dhm50.4.332-337. PMID: 33325012.)
Introduction: Healthcare acquired infections (HAIs) are associated with increased mortality, morbidity and prolonged hospital stays. Microbiological contamination of the hospital environment directly contributes to HAIs. Optimising environmental cleaning reduces transmission of HAIs. The hyperbaric chamber poses a specific challenge for infection control as certain disinfectants and alcohol-based hand sanitisers are prohibited due to fire risk. Patients often possess multiple risk factors for HAIs. This study compared the bacteria remaining on a surface (bioburden) after a standard clean and after adjunctive disinfection with an ultraviolet-C (UV-C) robot.
Methods: Internal hyperbaric chamber surfaces were first manually cleaned with Clinell® universal wipes and the floor was mopped with Whiteley neutral detergent. Allocated surfaces were swabbed using sterile cotton swabs and processed using a standard microbial culture and a bacteria-specific rapid metabolic assay. Bacterial contamination was also measured by direct contact plating on flat surfaces. The plexiglass ports were covered to protect from potential UV-C mediated damage and used as a negative control. A UV-C disinfection robot was then used to disinfect the chamber for 30 min, whereafter surfaces were swabbed again.
Results: There was a significantly greater mean reduction in bioburden following adjunctive UV-C disinfection than with standard cleaning alone. The surfaces not routinely manually cleaned (e.g., bench, phone) showed greatest reduction in bacterial load following UV-C cleaning.
Conclusions: There was a significant reduction in the bacterial load in the chamber following an adjunctive UV-C clean compared with that of a standard clean. Adjunctive cleaning of the hyperbaric chamber environment with a non-touch UV-C device shows promise as a method to reduce HAIs.
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
Ful article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):338–342. doi: 10.28920/dhm50.4.338-342. PMID: 33325013.
Effect of antiplatelet and/or anticoagulation medication on the risk of tympanic barotrauma in hyperbaric oxygen treatment patients, and development of a predictive model
Adam E Howard1, Peter Buzzacott2, Ian C Gawthrope1,3, Neil D Banham1
1 Department of Hyperbaric Medicine, Fiona Stanley Hospital, Western Australia
2 Pre-Hospital, Resuscitation and Emergency Care Research Unit, School of Nursing, Midwifery and Paramedicine, Curtin University, Western Australia
3 University of Notre Dame, Fremantle, Western Australia
Corresponding author: Dr Adam Howard, Department of Hyperbaric Medicine, Fiona Stanley Hospital, 11 Robin Warren Drive, Murdoch, WA 6150, Australia
Key words
Middle ear; Risk factors; Haematology; Women; Age; Data
Abstract
(Howard AE, Buzzacott P, Gawthrope IC, Banham ND. Effect of antiplatelet and/or anticoagulation medication on the risk of tympanic barotrauma in hyperbaric oxygen therapy patients, and development of a predictive model. Diving and Hyperbaric Medicine. 2020 December 20;50(4):338–342. doi: 10.28920/dhm50.4.338-342. PMID: 33325013.)
Introduction: Middle ear barotrauma (MEBt) is a common side effect of hyperbaric oxygen treatment (HBOT) and can result in pain, hearing loss, tinnitus and otorrhagia. The use of antiplatelet/anticoagulant drugs is thought to increase the risk and severity of MEBt during HBOT.
Methods: Single centre, retrospective observational cohort study of all patients treated with HBOT over a 4-year period (between 01 January 2015 to 31 December 2018) looking at the incidence of MEBt and the concurrent use of antiplatelet and/or anticoagulant drugs. MEBt was assessed by direct otoscopy of the tympanic membrane post-HBOT and scored using the modified Teed classification. Multivariate modelling assessed the relationship between antiplatelet and/or anticoagulation drug use, age, sex, and MEBt during HBOT.
Results: There was no evidence that antiplatelet and/or anticoagulation drugs increase the risk of tympanic barotrauma in HBOT patients. The prevalence of MEBt was higher in female patients than in males (χ2 P = 0.004), and increased with age (χ2 P = 0.048). No MEBt was recorded in patients undergoing recompression therapy for decompression sickness or cerebral arterial gas embolism.
Conclusions: In this retrospective single-centre study, antiplatelet and/or anticoagulation drugs did not affect the risk of MEBt, but both age and sex did, with greater prevalence of MEBt among older patients and females compared with younger patients and males. A predictive model, requiring further validation, may be helpful in assessing the likelihood of MEBt in patients undergoing HBOT.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):343-349. doi: 10.28920/dhm50.4.343-349. PMID: 33325014.
Xuebijing attenuates decompression-induced lung injuries
Wen-tao Meng1,2, Long Qing3, Quan Zhou1, Wei-gang Xu1
1 Department of Diving and Hyperbaric Medicine, Naval Special Medicine Center, Naval Medical University, Shanghai, China
2 Discipline of Military and Special Medicine, The 92493 Military Hospital of PLA, Huludao, China
3 Naval Diving Medical Discipline, Naval Special Medicine Center, Naval Medical University, Shanghai, China
Corresponding author: Professor Wei-gang Xu, Department of Diving and Hyperbaric Medicine, Naval Special Medicine Center, Naval Medical University, Shanghai, China
Key words
Decompression sickness; Decompression illness; Inflammation; Pulmonary oedema
Abstract
(Meng W, Qing L, Zhou Q, Xu W. Xuebijing attenuates decompression-induced lung injuries. Diving and Hyperbaric Medicine. 2020 December 20;50(4):343–349. doi: 10.28920/dhm50.4.343-349. PMID: 33325014.)
Introduction: The lung is among the primary organs involved in decompression sickness (DCS). Xuebijing (XBJ), a traditional Chinese medicine, has been widely used in the treatment of various acute lung diseases. This study aimed to explore potential benefit of XBJ on lung injuries induced by DCS in a rabbit model.
Methods: Twenty-four male New Zealand white rabbits underwent a simulated air dive to 50 meters’ sea water for 60 min with 2.5 min decompression, and received an intravenous injection of XBJ (5 ml·kg-1) or an equal volume of saline immediately following decompression. DCS signs were monitored for 24 h, and blood was sampled before simulated diving and at 6 h and 12 h following decompression for determination of inflammatory indices. Lung tissues were sampled after euthanasia for histology analysis and lung water content, as well as tumour necrosis factor-α level. Another six rabbits were used as control.
Results: XBJ significantly ameliorated lung injuries (lung wet/dry ratio and total protein content in bronchoalveolar lavage fluid), and notably inhibited systemic (serum level of interleukin-1β) and local (tumour necrosis factor-α in bronchoalveolar lavage fluid) inflammation responses.
Conclusions: The results strongly suggest the benefits of XBJ on ameliorating DCS lung injuries, which is possibly via inhibiting systemic and local inflammation. XBJ may be a potential candidate for the treatment of decompression-induced lung injuries.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Original article
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):350–355. doi: 10.28920/dhm50.4.350-355. PMID: 33325015.
Effects of freediving on middle ear and eustachian tube function
Moritz F Meyer1,2, Kristijana Knezic1, Stefanie Jansen1, Heinz D Klünter1, Eberhard D Pracht3, Maria Grosheva1
1 Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Germany
2 Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Essen, University Duisburg-Essen, Essen, Germany
3 German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
Corresponding author: Dr Moritz F Meyer, Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, University Hospital of Essen, Hufelandstraße 55, 45122 Essen, Germany
Key words
Tympanometry; Repetitive diving; Ear barotrauma; ENT; Risk factors; Valsalva manoeuvre
Abstract
(Meyer MF, Knezic K, Jansen S, Klünter HD, Pracht ED, Grosheva M. Effects of freediving on middle ear and eustachian tube function. Diving and Hyperbaric Medicine. 2020 December 20;50(4):350–355. doi: 10.28920/dhm50.4.350-355. PMID: 33325015.)
Introduction: During descent in freediving there is exposure to rapidly increasing pressure. Inability to quickly equalise middle ear pressure may cause trauma to the ear. This study aimed to evaluate the occurrence of pressure-related damage to the middle ear and the Eustachian tube during freediving and to identify possible risk factors.
Methods: Sixteen free divers performed diving sessions in an indoor pool 20 metres’ freshwater (mfw) deep. During each session, each diver performed four own free dives and up to four safety dives. Naso- and oto-endoscopy and Eustachian tube function tests were performed on the right and left ears before diving, between each session and after the last session. The otoscopic findings were classified according to the Teed classification (0 = normal tympanic membrane to 4 = perforation). Additionally, ENT-related complaints were assessed using a questionnaire.
Results: Participants performed 317 dives (on average 20 dives per diver, six per session). The average depth was 13.3 mfw. Pressure-related changes (Teed 1 and 2) were detected in 48 % of ears. Teed level increased significantly with an increasing number of completed sessions (P < 0.0001). Higher pressure-related damage (Teed 2) occurred in less experienced divers, was associated with significantly lower peak pressures in the middle ear and led to more ear-related symptoms. A preference for the Frenzel technique for middle ear pressure equalisation during freediving was shown.
Conclusions: Pressure exposure during freediving had a cumulative effect on the middle ear. Factors such as diving depth, diving experience and number of diving sessions correlated with the occurrence of higher Teed levels.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):356–362. doi: 10.28920/dhm50.4.356-362. PMID: 33325016.
Safety proposals for freediving time limits should consider the metabolic-rate dependence of oxygen stores depletion
Charlotte Sadler1, Kaighley Brett1, Aaron Heerboth1, Austin R Swisher2, Nader Mehregani2, Ross Touriel1, Daniel T Cannon2
1 Department of Emergency Medicine, University of California, San Diego, USA
2 School of Exercise and Nutritional Sciences, San Diego State University, San Diego, USA
Corresponding author: Dr Charlotte Sadler, Department of Emergency Medicine, University of California, San Diego, USA
Key words
Hypoxia; Breath-hold diving; Diving research; Hyperventilation; Metabolism; Apnoea; Apnea
Abstract
(Sadler C, Brett K, Heerboth A, Swisher AR, Mehregani N, Touriel R, Cannon DT. Safety proposals for freediving time limits should consider the metabolic-rate dependence of oxygen stores depletion. Diving and Hyperbaric Medicine. 2020 December 20;50(4):356–362. doi: 10.28920/dhm50.4.356-362. PMID: 33325016.)
Introduction: There is no required training for breath-hold diving, making dissemination of safety protocols difficult. A recommended breath-hold dive time limit of 60 s was proposed for amateur divers. However, this does not consider the metabolic-rate dependence of oxygen stores depletion. We aimed to measure the effect of apnoea time and metabolic rate on arterial and tissue oxygenation.
Methods: Fifty healthy participants (23 (SD 3) y, 22 women) completed four periods of apnoea for 60 s (or to tolerable limit) during rest and cycle ergometry at 20, 40, and 60 W. Apnoea was initiated after hyperventilation to achieve PETCO2 of approximately 25 mmHg. Pulse oximetry, frontal lobe oxygenation, and pulmonary gas exchange were measured throughout. We defined hypoxia as SpO2 < 88%.
Results: Static and exercise (20, 40, 60 W) breath-hold break times were 57 (SD 7), 50 (11), 48 (11), and 46 (11) s (F [2.432, 119.2] = 32.0, P < 0.01). The rise in PETCO2 from initiation to breaking of apnoea was dependent on metabolic rate (time × metabolic rate interaction; F [3,147] = 38.6, P < 0.0001). The same was true for the fall in SpO2 (F [3,147] = 2.9, P = 0.03). SpO2 fell to < 88% on 14 occasions in eight participants, all of whom were asymptomatic.
Conclusions: Independent of the added complexities of a fall in ambient pressure on ascent, the effect of apnoea time on hypoxia depends on the metabolic rate and is highly variable among individuals. Therefore, we contend that a universally recommended time limit for breath-hold diving or swimming is not useful to guarantee safety.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):363–369. doi: 10.28920/dhm50.4.363-369. PMID: 33325017.
A review of diving practices and outcomes following the diagnosis of a persistent (patent) foramen ovale in compressed air divers with a documented episode of decompression sickness
Christopher W Scarff1, John Lippmann2,3, Andrew W Fock1,3
1 Department of Intensive Care and Hyperbaric Medicine, Alfred Hospital, Melbourne, Australia
2 Australasian Diving Safety Foundation, Melbourne, Australia
3 Department of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
Corresponding author: Dr Christopher W Scarff, The Alfred, PO Box 315, Prahran 3181, VIC, Australia
Key words
Decompression illness; Persistent (patent) foramen ovale (PFO); Safety; Education; Diving research
Abstract
(Scarff CW, Lippmann J, Fock AW. A review of diving practices and outcomes following the diagnosis of a persistent (patent) foramen ovale in compressed air divers with a documented episode of decompression sickness. Diving and Hyperbaric Medicine. 2020 December 20;50(4):363–369. doi: 10.28920/dhm50.4.363-369. PMID: 33325017.)
Introduction: The presence of a persistent (patent) foramen ovale (PFO) increases the risk of decompression sickness (DCS) whilst diving with pressurised air. After the diagnosis of a PFO, divers will be offered a number of options for risk mitigation. The aim of this study was to review the management choices and modifications to diving practices following PFO diagnosis in the era preceding the 2015 joint position statement (JPS) on PFO and diving.
Methods: A retrospective study was conducted of divers sourced from both the Alfred Hospital, Melbourne and the Divers Alert Network Asia-Pacific during the period 2005–2015. Divers were contacted via a combination of phone, text, mail and email. Data collected included: diving habits (years, style and depths); DCS symptoms, signs and treatment; return to diving and modifications of dive practices; history of migraine and echocardiography (ECHO) pre- and post-intervention; ECHO technique(s) used, and success or failure of PFO closure (PFOC). Analyses were performed to compare the incidence of DCS pre- and post-PFO diagnosis.
Results: Seventy-three divers were interviewed. Sixty-eight of these returned to diving following the diagnosis of PFO. Thirty-eight underwent PFOC and chose to adopt conservative diving practices (CDPs); 15 chose PFOC with no modification to practices; 15 adopted CDPs alone; and five have discontinued diving. The incidence of DCS decreased significantly following PFOC and/or adoption of conservative diving practices. Of interest, migraine with aura resolved in almost all those who underwent PFOC.
Conclusions: Many divers had already adopted practices consistent with the 2015 JPS permitting the resumption of scuba diving with a lowering of the incidence of DCS to that of the general diving population. These results support the recommendations of the JPS.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):370–376. doi: 10.28920/dhm50.4.370-376. PMID: 33325018.
Decompression illness treated at the Geneva hyperbaric facility 2010–2016: A retrospective analysis of local cases
Julian Thaler1, Rodrigue Pignel2, Marie-Anne Magnan2, Michel Pellegrini2, Pierre Louge2
1 Department of Intensive Care Medicine, Valais Hospital, Sion, Switzerland
2 Hyperbaric Medicine, Geneva University Hospitals, Geneva, Switzerland
Corresponding author: Dr Julian Thaler, Department of Intensive Care Medicine, Valais Hospital, Avenue du Grand-Champsec 80, 1951 Sion, Switzerland
Key words
Diving; Decompression illness; Arterial gas embolism; Epidemiology; Scuba; Recompression
Abstract
(Thaler J, Pignel R, Magnan M-A, Pellegrini M, Louge P. Decompression illness treated at the Geneva hyperbaric facility 2010–2016: A retrospective analysis of local cases. Diving and Hyperbaric Medicine. 2020 December 20;50(4):370–376. doi: 10.28920/dhm50.4.370-376. PMID: 33325018.)
Introduction: The Geneva hyperbaric chamber is the main treatment centre for decompression illness (DCI) in Switzerland. The characteristics, symptomatology, treatment and short-term outcome of divers treated at this chamber have not previously been investigated.
Methods: This was a retrospective study of patients treated with hyperbaric oxygen (HBO) for DCI from 2010 to 2016. Data were analysed to provide a description of the cases and statistical analysis for possible factors associated with an unfavourable outcome.
Results: One hundred and thirty-five patients were treated for DCI. Ninety-two were included in the study. Sixty-four presented with neurological and 28 with mild DCI. One hundred and thirty-five patients were treated for DCI. Ninety-two were included in the study. Sixty-four presented with neurological and 28 with mild DCI. Patients with mild DCI mainly had musculoskeletal symptoms (79%). Patients with neurological DCI mainly had spinal (55%), followed by vestibular (36%) symptoms. Arterial gas embolism was diagnosed in 30% of cases. Diving depths ranged between 15 and 142 metres, and dive times between two and 241 min. Median time to treatment was 6 h. Patients with neurological DCI had a high rate (25%) of persisting deficits after treatment. Older age was associated with an unfavourable outcome in univariate but not in multivariate analysis. No adverse effects of HBO were observed. For spinal DCI, a high Boussuges score was associated with persisting deficits after treatment.
Conclusions: Our findings are consistent with other series. Severe DCI was associated with a high rate of persisting deficits. No single factor was associated with a negative outcome. A Boussuges score > 7 had sensitivity of 90% and positive predictive value 53% for predicting an unfavourable outcome in spinal DCI.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):377–385. doi: 10.28920/dhm50.4.377-385. PMID: 33325019.
Investigating critical flicker fusion frequency for monitoring gas narcosis in divers
Xavier CE Vrijdag1,2, Hanna van Waart1, Jamie W Sleigh1,3, Costantino Balestra4, Simon J Mitchell1,5
1 Department of Anaesthesiology, University of Auckland, Auckland, New Zealand
2 Deep Dive Dubai, Dubai, United Arab Emirates
3 Department of Anaesthesia, Waikato Hospital, Hamilton, New Zealand
4 Environmental, Occupational and Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium
5 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
Corresponding author: Xavier Vrijdag, Department of Anaesthesiology, School of Medicine, University of Auckland, Private bag 92019, Auckland 1142, New Zealand
Key words
CFFF; Diving research; Narcosis; Nitrogen; Oxygen; Physiology
Abstract
(Vrijdag XCE, van Waart H, Sleigh JW, Balestra C, Mitchell SJ. Investigating critical flicker fusion frequency for monitoring gas narcosis in divers. Diving and Hyperbaric Medicine. 2020 December 20;50(4):377–385. doi: 10.28920/dhm50.4.377-385. PMID: 33325019.)
Introduction: Critical flicker fusion frequency (CFFF) has been used in various studies to measure the cognitive effects of gas mixtures at depth, sometimes with conflicting or apparently paradoxical results. This study aimed to evaluate a novel automatic CFFF method and investigate whether CFFF can be used to monitor gas-induced narcosis in divers.
Methods: Three hyperbaric chamber experiments were performed: 1) Automated and manual CFFF measurements during air breathing at 608 kPa (n = 16 subjects); 2) Manual CFFF measurements during air and heliox breathing at sea level (101.3 kPa) and 608 kPa (n = 12); 3) Manual CFFF measurements during oxygen breathing at sea level, 142 and 284 kPa (n = 10). All results were compared to breathing air at sea level.
Results: Only breathing oxygen at sea level, and at 284 kPa, caused a significant decrease in CFFF (2.5% and 2.6% respectively compared to breathing air at sea level. None of the other conditions showed a difference with sea level air breathing.
Conclusions: CFFF did not significantly change in our experiments when breathing air at 608 kPa compared to air breathing at sea level pressure using both devices. Based on our results CFFF does not seem to be a sensitive tool for measuring gas narcosis in divers in our laboratory setting.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):386–390. doi: 10.28920/dhm50.4.386-390. PMID: 33325020.
Hyperbaric oxygen but not hyperbaric air increases insulin sensitivity in men with type 2 diabetes mellitus
David C Wilkinson1,2, Ian M Chapman2, Leonie K Heilbronn2
1 Hyperbaric Medicine Unit, Royal Adelaide Hospital, Adelaide, Australia
2 Adelaide Medical School, The University of Adelaide, Adelaide, Australia
Corresponding author: Dr David Wilkinson, Hyperbaric Medicine Unit, Royal Adelaide Hospital, Port Road, Adelaide SA 5000, Australia
Key words
Blood sugar level; Diabetes; Endocrinology; Hyperbaric research; Metabolism
Abstract
(Wilkinson DC, Chapman IM, Heilbronn LK. Hyperbaric oxygen but not hyperbaric air increases insulin sensitivity in men with type 2 diabetes mellitus. Diving and Hyperbaric Medicine. 2020 December 20;50(4):386–390. doi: 10.28920/dhm50.4.386-390. PMID: 33325020.)
Introduction: We have previously shown that hyperbaric oxygen treatment (HBOT) increased insulin sensitivity in men who were obese or overweight, both with and without type 2 diabetes. The aim of this study was to test whether this insulin-sensitising effect is seen in hyperbaric air (HA).
Methods: Men with type 2 diabetes who were obese or overweight were randomised to two groups: HBOT (n = 13) or HA (n = 11). A hyperinsulinaemic euglycaemic glucose clamp (80 mU·m-2·min-1) was performed at baseline and during hyperbaric intervention. Both groups were compressed to 203 kPa (two atmospheres absolute) for 90 minutes followed by a linear 30-minute decompression. The HBOT group breathed oxygen via a hood while the HA group breathed chamber air. Insulin sensitivity was assessed from the glucose infusion rate (GIR) during the last 30 minutes in the hyperbaric chamber (SS1) and the first 30 minutes after exit (SS2). Data were analysed for within-group effect by paired student t-test and between-group effect by one-way ANOVA.
Results: HBOT increased GIR by a mean 26% at SS1 (P = 0.04) and 23% at SS2 (P = 0.018). There was no significant change in GIR during or after HA. A between-group effect was evident for the change in GIR at SS1 in HBOT vs HA (P = 0.036).
Conclusions: The pathway by which insulin sensitivity is increased in men with type 2 diabetes requires the high oxygen partial pressures of HBOT and should be further investigated. Insulin sensitivity was not changed in hyperbaric air.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):391–398. doi: 10.28920/dhm50.4.391-398. PMID: 33325021.
Dysbaric osteonecrosis (DON) among the artisanal diving fishermen of Yucatán, Mexico
Daniel Popa1,2, Anthony Medak2, Walter Chin3, Oswaldo Huchim-Lara4, Evelyne Fliszar5, Tudor Hughes5, Ian Grover2
1 Rush University Department of Emergency Medicine, Chicago IL, USA
2 UCSD Department of Emergency Medicine, Division of Hyperbaric and Undersea Medicine, San Diego, USA
3 Winship Cancer Institute of Emory University, Atlanta GA, USA
4 La Universidad Marista de Mérida School of Medicine, Mérida, Yucátan, Mexico
5 UCSD Department of Radiology, San Diego CA, USA
Corresponding author: Dr Daniel Popa, Rush University Department of Emergency Medicine, 1750 W. Harrison St., Kellogg Suite 108, Chicago, IL 60612, USA
Key words
Bone necrosis; Decompression sickness; Diving at work; Indigenous divers; Surface supplied diving
Abstract
Popa D, Medak A, Chin W, Huchim-Lara O, Fliszar E, Hughes T, Grover I. Dysbaric osteonecrosis (DON) among the artisanal diving fishermen of Yucatán, Mexico. Diving and Hyperbaric Medicine. 2020 December 20;50(4):391–398. doi: 10.28920/dhm50.4.391-398. PMID: 33325021.)
Introduction: Artisanal diving fishermen in Yucatán, Mexico have high rates of decompression sickness as a result of frequently unsafe diving practices with surface supplied compressed air. In this study, we investigated the prevalence of dysbaric osteonecrosis (DON), a type of avascular necrosis, in the most susceptible joints in a cohort of these fishermen.
Methods: We performed radiographs of bilateral shoulders, hips, and knees of 39 fishermen in Mexico and surveyed them about their medical and diving histories. We performed pairwise correlations to examine if the fishermen’s diving behaviours affected the numbers of joints with DON.
Results: The radiographs revealed Grade II or higher DON in 30/39 (76.9%) of the fishermen. Twenty-two of 39 fishermen (56.4%) had at least two affected joints. The number of joints with DON positively correlates with the lifetime maximum diving depth and average bottom time.
Conclusions: These findings represent among the highest prevalence rates of DON in divers and reflect the wide-spread scale of decompression sickness among these fishermen. Through this work, we hope to further educate the fishermen on the sequelae of their diving with the aim of improving their diving safety.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):399–404. doi: 10.28920/dhm50.4.399-404. PMID: 33325022.
Children and diving, a guideline
Mattijn Buwalda1, Abraham L Querido2, Robert A van Hulst3
1 Medical and Educational Services, De Meent 51A, Odijk, The Netherlands
2 Praktijk Querido, Larenseweg 14, Hilversum, The Netherlands
3 Department of Anaesthesiology and Hyperbaric Medicine, Academic Medical Center, Amsterdam, The Netherlands
Corresponding author: Dr Mattijn Buwalda, Medical and Educational Services, De Meent 51A, Odijk, The Netherlands
Key words
Recreational diving; Children; Physiology; Psychology; Diving incidents; Review article
Abstract
(Buwalda M, Querido AL, van Hulst RA. Children and diving, a guideline. Diving and Hyperbaric Medicine. 2020 December 20;50(4):399–404. doi: 10.28920/dhm50.4.399-404. PMID: 33325022.)
Scuba diving is an increasingly popular recreational activity in children and adolescents. During the dive medical examination aspects of human physiology, anatomy, and psychology, that differ between adults and children, deserve our special attention. For example, lack of mental maturity, diminished Eustachian tube function and heat loss can pose problems during diving. It is important that children who wish to take up scuba diving are seen by a dive physician, with extra attention to Eustachian tube function. In children, asthma, bronchial hyperreactivity, pulmonary hypertension, and right-to-left shunts are contra-indications for scuba diving. Attention deficit hyperactivity disorder is a relative contra-indication. This article provides a review of the current literature and presents recommendations for recreational diving in children and adolescents. These recommendations are based solely on ‘expert’ opinion and were accepted by the Dutch Society of Diving and Hyperbaric Medicine in 2020.
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: Guideline
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):405–412. doi: 10.28920/dhm50.4.405-412. PMID: 33325023.
First impressions: Use of the Azoth Systems O’Dive subclavian bubble monitor on a liveaboard dive vessel
Peter Germonpré1,2,3, Paul Van der Eecken4, Elke Van Renterghem2,5, Faye-Lisa Germonpré6, Costantino Balestra3,7
1 Centre for Hyperbaric Oxygen Therapy, Military Hospital Brussels, Belgium
2 Medyssea EVR, Expedition and Diving Medicine, Ghent, Belgium
3 Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Brussels, Belgium
4 ENT Department, St Lucas Hospital, Ghent, Belgium
5 Emergency Department, St Lucas Hospital, Ghent, Belgium
6 Medical Student, Ghent University, Ghent, Belgium
7 DAN Europe Research Department, Brussels, Belgium and Roseto, Italy
Corresponding author: Dr Peter Germonpré, Centre for Hyperbaric Oxygen Therapy, Military Hospital Brussels, Belgium
Key words
Bubble detection; Bubbles; Decompression; Recreational diving; Risk assessment; Surveillance
Abstract
(Germonpré P, Van der Eecken P, Van Renterghem E, Germonpré F-L, Balestra C. First impressions: Use of the Azoth Systems O’Dive subclavian bubble monitor on a liveaboard dive vessel. Diving and Hyperbaric Medicine. 2020 December 20;50(4):405–412. doi: 10.28920/dhm50.4.405-412. PMID: 33325023.)
Introduction: The Azoth Systems O’Dive bubble monitor is marketed at recreational and professional divers as a tool to improve personal diving decompression safety. We report the use of this tool during a 12-day dive trip aboard a liveaboard vessel.
Methods: Six divers were consistently monitored according to the user manual of the O’Dive system. Data were synchronised with the Azoth server whenever possible (depending on cell phone data signal). Information regarding ease of use, diver acceptance and influence on dive behaviour were recorded.
Results: In total, 157 dives were completely monitored over 11 diving days. Formal evaluations were only available after six days because of internet connection problems. Sixty-one dives resulted in the detection of bubbles, mostly in one diver, none of which produced any symptoms of decompression illness.
Conclusions: The O’Dive system may contribute to increasing dive safety by making divers immediately aware of the potential consequences of certain types of diving behaviour. It was noted that bubble monitoring either reinforced divers in their safe diving habits or incited them to modify their dive planning. Whether this is a lasting effect is not known.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):413–416. doi: 10.28920/dhm50.4.413-416. PMID: 33325024.
Considerations for scuba and breath-hold divers during the COVID-19 pandemic: A call for awareness
Antonis Elia1, Mikael Gennser1
1 Division of Environmental Physiology, School of Chemistry, Bioengineering and Health, KTH Royal Institute of Technology, Stockholm, Sweden
Corresponding author: Dr Antonis Elia, Division of Environmental Physiology, School of Chemistry, Bioengineering and Health, KTH Royal Institute of Technology, Stockholm, Sweden
Key words
Apnoea; Breath-hold diving; COVID-19; Hypoxaemia; Scuba diving; SARS-CoV-2; Lungs
Abstract
(Elia A, Gennser M. Considerations for scuba and breath-hold divers during the COVID-19 pandemic: A call for awareness. Diving and Hyperbaric Medicine. 2020 December 20;50(4):413–416. doi: 10.28920/dhm50.4.413-416. PMID: 33325024.)
In late 2019, a highly pathogenic novel coronavirus (CoV), severe acute respiratory syndrome (SARS)-CoV-2 emerged from Wuhan, China and led to a global pandemic. SARS-CoV-2 has a predilection for the pulmonary system and can result in serious pneumonia necessitating hospitalisation. Computed tomography (CT) chest scans of patients with severe symptoms, show signs of multifocal bilateral ground or ground-glass opacities (GGO) associated with consolidation areas with patchy distribution. However, it is less well known that both asymptomatic and mild symptomatic patients may exhibit similar lung changes. Presumably, the various pathological changes in the lungs may increase the risk of adverse events during diving (e.g., lung barotrauma, pulmonary oedema, etc.), thus these lung manifestations need to be considered prior to allowing resumption of diving. Presently, it is not known how the structural changes in the lungs develop and to what extent they resolve, in particular in asymptomatic carriers and patients with mild disease. However, current evidence indicates that a month of recovery may be too short an interval to guarantee complete pulmonary restitution even after COVID-19 infections not demanding hospital care.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):417–420. doi: 10.28920/dhm50.4.417-420. PMID: 33325025.
Common mental health conditions among navy divers: A brief report
Charles H Van Wijk1, Jarred H Martin2, Nazneen Firfirey1
1 Institute for Maritime Medicine, Simon’s Town, South Africa
2 Department of Psychology, University of Pretoria, South Africa
Corresponding author: Dr Charles H Van Wijk, Institute for Maritime Medicine, PO Box 494, Simon’s Town 7995, South Africa
Key words
Anxiety; Depression; Health surveillance; Psychology
Abstract
(Van Wijk CH, Martin JH, Firfirey N. Common mental health conditions among navy divers: A brief report. Diving and Hyperbaric Medicine. 2020 December 20;50(4):417–420. doi: 10.28920/dhm50.4.417-420. PMID: 33325025.)
Introduction: A recent article reported on common mental health conditions among recreational scuba divers, and observed that the prevalence mirrored national population figures. This raised the question of the extent to which this might also be the case among professional divers. No data on commercial divers could be located; this paper presents the situation among navy divers.
Methods: Mental health survey data from 132 South African Navy divers were reviewed to describe the 12-month prevalence of common mood, anxiety, and alcohol misuse disorders.
Results: Prevalence of common mood and anxiety conditions appeared to reflect local general population estimates, and the occurrence of alcohol misuse was higher than local population figures, although the usefulness of the population data could be challenged.
Conclusions: It appeared that common mental health conditions in both sport and navy divers may generally conform to their respective local general population estimates. If this were to be the case in the broader professional diving environment as well, the inclusion of some form of formal mental health screening during commercial diving medical examinations may be beneficial.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):421–423. doi: 10.28920/dhm50.4.421-423. PMID: 33325026.
Impaired consciousness when scuba diving associated with vasovagal syncope
Peter Wilmshurst1, Margaret Clamp2
1 Royal Stoke University Hospital, Stoke-on-Trent, United Kingdom
2 MC Occupational Health, Colwick, Nottingham, United Kingdom
Corresponding author: Dr Peter Wilmshurst, Consultant Cardiologist, Royal Stoke University Hospital, Stoke-on-Trent, ST4 6QG, United Kingdom
Key words
Vasovagal syncope; Neurocardiogenic syncope; Faints; Micturition syncope; Scuba diving
Abstract
(Wilmshurst P, Clamp M. Impaired consciousness when scuba diving associated with vasovagal syncope. Diving and Hyperbaric Medicine. 2020 December 20;50(4):421–423. doi: 10.28920/dhm50.4.421-423. PMID: 33325026.)
Introduction: Drowning is likely to result from impairment of consciousness when scuba diving. Causes include toxic effects of breathing gas, including nitrogen narcosis and oxygen toxicity, and arterial gas embolism.
Methods: Review of the medical records of scuba divers who had impaired consciousness underwater that could not be attributed to toxic effects of breathing gas or arterial gas embolism.
Results: Four scuba divers had episodes of impaired consciousness when at shallow depths (8−18 m) underwater. The descriptions of the episodes were very similar. Three had histories of recurrent episodes of vasovagal syncope on land.
Conclusions: Absence of other causes for their impaired consciousness underwater leads to the conclusion that the probable cause was vasovagal syncope.
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
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):424–430. doi: 10.28920/dhm50.4.424-430. PMID: 33325027.
Persistent extravascular bubbles on radiologic imaging after recompression treatment for decompression sickness: A case report
Juan C Dapena1, Corine A Lansdorp2, Simon J Mitchell3,4
1 Navy Medicine Operational Training Center, Hyperbaric Medicine Department, Pensacola (FL), USA
2 Amsterdam University Medical Centre, location AMC, Department of Anaesthesiology/Hyperbaric Medicine, Amsterdam, The Netherlands
3 Department of Anaesthesiology, School of Medicine, University of Auckland, New Zealand
4 Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
Corresponding author: Dr Juan C Dapena, Navy Medicine Operational Training Center, Hyperbaric Medicine Department, 220 Hovey Rd, Pensacola, Florida, 32508, USA
Key words
Decompression illness; Computed tomography; Hyperbaric oxygen; Residual symptoms; Bubbles; Nitrogen
Abstract
(Dapena JC, Lansdorp CA, Mitchell SJ. Persistent extravascular bubbles on radiologic imaging after recompression treatment for decompression sickness: A case report. Diving and Hyperbaric Medicine. 2020 December 20;50(4):424–430. doi: 10.28920/dhm50.4.424-430. PMID: 33325027.)
Decompression sickness (DCS) is a condition arising when dissolved inert gas in tissue forms extravascular and/or intravascular bubbles during or after depressurisation. Patients are primarily treated with 100% oxygen and recompression, which is often assumed to lead to resolution of bubbles. After this, repeated hyperbaric exposures can be provided in case of persistent symptoms, with oxygen delivery to ischaemic tissues, anti-inflammatory properties and reduction of oedema considered the main mechanisms of action. In this case report we present the history and imaging of a diver diagnosed with DCS that was treated with two US Navy Treatment Table 6 recompressions, but who still had multiple extravascular bubbles apparent on CT-imaging after these hyperbaric treatments. Based on these findings we hypothesise that, contrary to general belief, it is possible that large extravascular bubbles can persist after definitive treatment for DCS.
Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.
Publication Type: Case report
Full article available here.
2020 December;50(4)
Diving Hyperb Med. 2020 December 20;50(4):431–436. doi: 10.28920/dhm50.4.431-436. PMID: 33325028.
Hyperbaric oxygen treatment of central retinal vein occlusion with cilioretinal artery occlusion secondary to hormonal treatment: Case report and review
Asma Khallouli1, Khaled Khelifi1, Rahma Saidane1, Racem Choura1, Afef Maalej1, Raja Ben Sassi2
1 Department of Ophthalmology, Military Hospital of Tunis, Tunisia
2 Department of Hyperbaric Oxygen Therapy, Military Hospital of Tunis, Tunisia
Corresponding author: Dr Racem Choura, Department of Ophthalmology, Military Hospital of Tunis, Mont Fleury- 1008, Tunisia
Key words
Cilioretinal artery occlusion; Retinal vein occlusion; Fertility agents; Female
Abstract
(Khallouli A, Khelifi K, Saidane R, Choura R, Maalej A, Ben Sassi R. Hyperbaric oxygen treatment of central retinal vein occlusion with cilioretinal artery occlusion secondary to hormonal treatment: Case report and review. Diving and Hyperbaric Medicine. 2020 December 20;50(4):431–436. doi: 10.28920/dhm50.4.431-436. PMID: 33325028.)
Introduction: This report describes a case of central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CLRAO) after hormonal treatment for induction of ovulation that was successfully treated with hyperbaric oxygen.
Case report: A 48 year-old woman was admitted to our department for sudden blurred vision in her left eye. The patient had a history of 3-months hormonal treatment for induction of ovulation. The best corrected visual acuity was 7/10 (20/32) in the left eye and 10/10 (20/20) in the right eye. Fundus examination of the left eye revealed flame-shaped haemorrhages, whitening of the retina along the distribution of cilioretinal artery and tortuous retinal veins. Fluorescein angiography confirmed the combination of a non-ischaemic CRVO with CLRAO. The patient was treated with a 2 h session of hyperbaric oxygen at 253 kPa (2.5 atmospheres absolute) once daily for a total of 30 sessions. Best corrected visual acuity improved to 10/10 (20/20) in the left eye.
Conclusions: CRVO and CLRAO are both occlusive disorders. HBOT is a safe low-cost treatment modality that can be beneficial in some ocular pathologies. It can maintain oxygenation of the retina through the choroidal blood supply, decrease oedema and preserve compromised tissue adjacent to the ischaemic area.
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