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Mitchell SJ. Decompression illness: a comprehensive overview. Diving Hyperb Med 2024; 54:1-53. [PMID: 38537300 PMCID: PMC11098596 DOI: 10.28920/dhm54.1.suppl.1-53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 01/31/2024] [Indexed: 05/20/2024]
Abstract
Decompression illness is a collective term for two maladies (decompression sickness [DCS] and arterial gas embolism [AGE]) that may arise during or after surfacing from compressed gas diving. Bubbles are the presumed primary vector of injury in both disorders, but the respective sources of bubbles are distinct. In DCS bubbles form primarily from inert gas that becomes dissolved in tissues over the course of a compressed gas dive. During and after ascent ('decompression'), if the pressure of this dissolved gas exceeds ambient pressure small bubbles may form in the extravascular space or in tissue blood vessels, thereafter passing into the venous circulation. In AGE, if compressed gas is trapped in the lungs during ascent, pulmonary barotrauma may introduce bubbles directly into the pulmonary veins and thence to the systemic arterial circulation. In both settings, bubbles may provoke ischaemic, inflammatory, and mechanical injury to tissues and their associated microcirculation. While AGE typically presents with stroke-like manifestations referrable to cerebral involvement, DCS can affect many organs including the brain, spinal cord, inner ear, musculoskeletal tissue, cardiopulmonary system and skin, and potential symptoms are protean in both nature and severity. This comprehensive overview addresses the pathophysiology, manifestations, prevention and treatment of both disorders.
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Affiliation(s)
- Simon J Mitchell
- Department of Anaesthesiology, School of Medicine, University of Auckland, Auckland, New Zealand
- Department of Anaesthesia, Auckland City Hospital, Auckland, New Zealand
- Slark Hyperbaric Medicine Unit, North Shore Hospital, Auckland, New Zealand
- Corresponding address: Department of Anaesthesiology, School of Medicine, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand, ORCiD: 0000-0002-5149-6371,
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Doolette DJ, Murphy FG. Within-diver variability in venous gas emboli (VGE) following repeated dives. Diving Hyperb Med 2023; 53:333-339. [PMID: 38091593 PMCID: PMC10944664 DOI: 10.28920/dhm53.4.333-339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/10/2023] [Indexed: 12/18/2023]
Abstract
Introduction Venous gas emboli (VGE) are widely used as a surrogate endpoint instead of decompression sickness (DCS) in studies of decompression procedures. Peak post-dive VGE grades vary widely following repeated identical dives but little is known about how much of the variability in VGE grades is proportioned between-diver and within-diver. Methods A retrospective analysis of 834 man-dives on six dive profiles with post-dive VGE measurements was conducted under controlled laboratory conditions. Among these data, 151 divers did repeated dives on the same profile on two to nine occasions separated by at least one week (total of 693 man-dives). Data were analysed for between- and within-diver variability in peak post-dive VGE grades using mixed-effect models with diver as the random variable and associated intraclass correlation coefficients. Results Most divers produced a wide range of VGE grades after repeated dives on the same profile. The intraclass correlation coefficient (repeatability) was 0.33 indicating that 33% of the variability in VGE grades is between-diver variability; correspondingly, 67% of variability in VGE grades is within-diver variability. DCS cases were associated with an individual diver's highest VGE grades and not with their lower VGE grades. Conclusions These data demonstrate large within-diver variability in VGE grades following repeated dives on the same dive profile and suggest there is substantial within-diver variability in susceptibility to DCS. Post-dive VGE grades are not useful for evaluating decompression practice for individual divers.
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Affiliation(s)
- David J Doolette
- Navy Experimental Diving Unit, Panama City, Florida, USA
- Department of Anaesthesiology, University of Auckland, New Zealand
- Corresponding author: Associate Professor David J Doolette, Navy Experimental Diving Unit, Panama City, Florida, USA, ORCiD: 0000-0001-9027-3536,
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Asya M, Axel B. Commentary: Comparison of newer hand-held ultrasound devices for post-dive venous gas emboli quantification to standard echocardiography. Front Physiol 2023; 13:1074436. [PMID: 36685195 PMCID: PMC9849592 DOI: 10.3389/fphys.2022.1074436] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 12/19/2022] [Indexed: 01/06/2023] Open
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Plogmark O, Hjelte C, Ekström M, Frånberg O. Agreement between ultrasonic bubble grades using a handheld self-positioning Doppler product and 2D cardiac ultrasound. Diving Hyperb Med 2022; 52:281-285. [PMID: 36525686 PMCID: PMC10017197 DOI: 10.28920/dhm52.4.281-285] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 10/22/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Intravascular bubble load after decompression can be detected and scored using ultrasound techniques that measure venous gas emboli (VGE). The aim of this study was to analyse the agreement between ultrasonic bubble grades from a handheld self-positioning product, the O'Dive™, and cardiac 2D ultrasound after decompression. METHODS VGE were graded with both bilateral subclavian vein Doppler ultrasound (modified Spencer scale) and 2D cardiac images (Eftedal Brubakk scale). Agreement was analysed using weighted kappa (Kw). Analysis with Kw was made for all paired grades, including measurements with and without zero grades, and for each method's highest grades after each dive. RESULTS A total of 152 dives yielded 1,113 paired measurements. The Kw agreement between ultrasound VGE grades produced by cardiac 2D images and those from the O'Dive was 'fair'; when zero grades were excluded the agreement was 'poor'. The O'Dive was found to have a lower sensitivity to detect VGE compared to 2D cardiac image scoring. CONCLUSIONS Compared to 2D cardiac image ultrasound, the O'Dive yielded generally lower VGE grades, which resulted in a low level of agreement (fair to poor) with Kw.
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Affiliation(s)
- Oscar Plogmark
- Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Respiratory Medicine and Allergology, Lund, Sweden
- Swedish Armed Forces Diving and Naval Medicine Center, Swedish Armed Forces, Karlskrona, Sweden
- Corresponding author: Oscar Plogmark, Sten Bergmans väg 21, 121 46 Johanneshov, Sweden,
| | - Carl Hjelte
- Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Respiratory Medicine and Allergology, Lund, Sweden
- Swedish Armed Forces Diving and Naval Medicine Center, Swedish Armed Forces, Karlskrona, Sweden
- Sahlgrenska University Hospital, Anesthesia and Intensive Care. Gothenburg, Sweden
| | - Magnus Ekström
- Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Respiratory Medicine and Allergology, Lund, Sweden
| | - Oskar Frånberg
- Swedish Armed Forces Diving and Naval Medicine Center, Swedish Armed Forces, Karlskrona, Sweden
- Blekinge Institute of Technology, Department of Mathematics and Natural Science, Karlskrona, Sweden
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Vascular Function Recovery Following Saturation Diving. Medicina (B Aires) 2022; 58:medicina58101476. [PMID: 36295636 PMCID: PMC9610043 DOI: 10.3390/medicina58101476] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/07/2022] [Accepted: 10/13/2022] [Indexed: 11/28/2022] Open
Abstract
Background and Objectives: Saturation diving is a technique used in commercial diving. Decompression sickness (DCS) was the main concern of saturation safety, but procedures have evolved over the last 50 years and DCS has become a rare event. New needs have evolved to evaluate the diving and decompression stress to improve the flexibility of the operations (minimum interval between dives, optimal oxygen levels, etc.). We monitored this stress in saturation divers during actual operations. Materials and Methods: The monitoring included the detection of vascular gas emboli (VGE) and the changes in the vascular function measured by flow mediated dilatation (FMD) after final decompression to surface. Monitoring was performed onboard a diving support vessel operating in the North Sea at typical storage depths of 120 and 136 msw. A total of 49 divers signed an informed consent form and participated to the study. Data were collected on divers at surface, before the saturation and during the 9 h following the end of the final decompression. Results: VGE were detected in three divers at very low levels (insignificant), confirming the improvements achieved on saturation decompression procedures. As expected, the FMD showed an impairment of vascular function immediately at the end of the saturation in all divers but the divers fully recovered from these vascular changes in the next 9 following hours, regardless of the initial decompression starting depth. Conclusion: These changes suggest an oxidative/inflammatory dimension to the diving/decompression stress during saturation that will require further monitoring investigations even if the vascular impairement is found to recover fast.
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Fichtner A, Brunner BP, Pohl T, Grab T, Fieback T, Koch T. A Doppler ultrasound self-monitoring approach for detection of relevant individual decompression stress in scuba diving. Intern Emerg Med 2022; 17:173-180. [PMID: 34241767 PMCID: PMC8841331 DOI: 10.1007/s11739-021-02802-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 07/01/2021] [Indexed: 11/29/2022]
Abstract
Observing modern decompression protocols alone cannot fully prevent diving injuries especially in repetitive diving. Professional audio Doppler bubble measurements are not available to sports scuba divers. If those non-professionals were able to learn audio Doppler self-assessment for bubble grading, such skill could provide significant information on individual decisions with respect to diving safety. We taught audio Doppler self-assessment of subclavian and precordial probe position to 41 divers in a 45-min standardized, didactically optimized training. Assessment before and after air dives within sports diving limits was made through 684 audio Doppler measurements in dive-site conditions by both trained divers and a medical professional, plus additional 2D-echocardiography reference. In all dives (average maximum depth 22 m; dive time 44 min), 33% of all echocardiography measurements revealed bubbles. The specificity of audio bubble detection in combination of both detection sites was 95%, and sensitivity over all grades was 40%, increasing with higher bubble grades. Dive-site audio-Doppler-grading underestimated echo-derived bubble grades. Bubble detection sensitivity of audio Doppler self-assessments, compared to an experienced examiner, was 62% at subclavian and 73% at precordial position. 6 months after the training and 4.5 months after the last measurement, the achieved Doppler skill level remained stable. Audio Doppler self-assessment can be learned by non-professionals in a single teaching intervention. Despite accurate bubble grading is impossible in dive-site conditions, relevant high bubble grades can be detected by non-professionals. This qualitative information can be important in self-evaluating decompression stress and assessing measures for increased diving safety.
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Affiliation(s)
- Andreas Fichtner
- Head of Emergency Department and OR Management, Kreiskrankenhaus Freiberg, Donatsring 20, 09599 Freiberg, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | | | - Thomas Pohl
- Scientific Diving Center, TU Bergakademie Freiberg, Freiberg, Germany
| | - Thomas Grab
- Scientific Diving Center, TU Bergakademie Freiberg, Freiberg, Germany
| | - Tobias Fieback
- Scientific Diving Center, TU Bergakademie Freiberg, Freiberg, Germany
| | - Thea Koch
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Balestra C, Guerrero F, Theunissen S, Germonpré P, Lafère P. Physiology of repeated mixed gas 100-m wreck dives using a closed-circuit rebreather: a field bubble study. Eur J Appl Physiol 2021; 122:515-522. [PMID: 34839432 PMCID: PMC8627581 DOI: 10.1007/s00421-021-04856-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/19/2021] [Indexed: 10/25/2022]
Abstract
PURPOSE Data regarding decompression stress after deep closed-circuit rebreather (CCR) dives are scarce. This study aimed to monitor technical divers during a wreck diving expedition and provide an insight in venous gas emboli (VGE) dynamics. METHODS Diving practices of ten technical divers were observed. They performed a series of three consecutive daily dives around 100 m. VGE counts were measured 30 and 60 min after surfacing by both cardiac echography and subclavian Doppler graded according to categorical scores (Eftedal-Brubakk and Spencer scale, respectively) that were converted to simplified bubble grading system (BGS) for the purpose of analysis. Total body weight and fluids shift using bioimpedancemetry were also collected pre- and post-dive. RESULTS Depth-time profiles of the 30 recorded man-dives were 97.3 ± 26.4 msw [range: 54-136] with a runtime of 160 ± 65 min [range: 59-270]. No clinical decompression sickness (DCS) was detected. The echographic frame-based bubble count par cardiac cycle was 14 ± 13 at 30 min and 13 ± 13 at 60 min. There is no statistical difference neither between dives, nor between time of measurements (P = 0.07). However, regardless of the level of conservatism used, a high incidence of high-grade VGE was detected. Doppler recordings with the O'dive were highly correlated with echographic recordings (Spearman r of 0.81, P = 0.008). CONCLUSION Although preliminary, the present observation related to real CCR deep dives questions the precedence of decompression algorithm over individual risk factors and pleads for an individual approach of decompression.
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Affiliation(s)
- Costantino Balestra
- Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Avenue Schaller, 91, 1160, Brussels, Belgium.,Physical Activity Teaching Unit, Motor Sciences Department, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium.,DAN Europe Research Department, Brussels, Belgium
| | - François Guerrero
- Laboratoire ORPHY, EA 4324, Université de Bretagne Occidentale, Brest, France
| | - Sigrid Theunissen
- Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Avenue Schaller, 91, 1160, Brussels, Belgium
| | - Peter Germonpré
- Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Avenue Schaller, 91, 1160, Brussels, Belgium.,Centre for Hyperbaric Oxygen Therapy, Military Hospital Queen Astrid, Brussels, Belgium.,DAN Europe Research Department, Brussels, Belgium
| | - Pierre Lafère
- Environmental, Occupational, Ageing (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), Avenue Schaller, 91, 1160, Brussels, Belgium. .,Centre for Hyperbaric Oxygen Therapy, Military Hospital Queen Astrid, Brussels, Belgium. .,Laboratoire ORPHY, EA 4324, Université de Bretagne Occidentale, Brest, France. .,DAN Europe Research Department, Brussels, Belgium.
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Balestra C, Lambrechts K, Mrakic-Sposta S, Vezzoli A, Levenez M, Germonpré P, Virgili F, Bosco G, Lafère P. Hypoxic and Hyperoxic Breathing as a Complement to Low-Intensity Physical Exercise Programs: A Proof-of-Principle Study. Int J Mol Sci 2021; 22:ijms22179600. [PMID: 34502508 PMCID: PMC8431767 DOI: 10.3390/ijms22179600] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/27/2021] [Accepted: 09/01/2021] [Indexed: 12/14/2022] Open
Abstract
Inflammation is an adaptive response to both external and internal stimuli including infection, trauma, surgery, ischemia-reperfusion, or malignancy. A number of studies indicate that physical activity is an effective means of reducing acute systemic and low-level inflammation occurring in different pathological conditions and in the recovery phase after disease. As a proof-of-principle, we hypothesized that low-intensity workout performed under modified oxygen supply would elicit a "metabolic exercise" inducing a hormetic response, increasing the metabolic load and oxidative stress with the same overall effect expected after a higher intensity or charge exercise. Herein, we report the effect of a 5-week low-intensity, non-training, exercise program in a group of young healthy subjects in combination with the exposure to hyperoxia (30% and 100% pO2, respectively) or light hypoxia (15% pO2) during workout sessions on several inflammation and oxidative stress parameters, namely hemoglobin (Hb), redox state, nitric oxide metabolite (NOx), inducible nitric oxide synthase (iNOS), inflammatory cytokine expression (TNF-α, interleukin (IL)-6, IL-10), and renal functional biomarkers (creatinine, neopterin, and urates). We confirmed our previous reports demonstrating that intermittent hyperoxia induces the normobaric oxygen paradox (NOP), a response overlapping the exposure to hypoxia. Our data also suggest that the administration of modified air composition is an expedient complement to a light physical exercise program to achieve a significant modulation of inflammatory and immune parameters, including cytokines expression, iNOS activity, and oxidative stress parameters. This strategy can be of pivotal interest in all those conditions characterized by the inability to achieve a sufficient workload intensity, such as severe cardiovascular alterations and articular injuries failing to effectively gain a significant improvement of physical capacity.
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Affiliation(s)
- Costantino Balestra
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (K.L.); (M.L.); (P.G.); (P.L.)
- Physical Activity Teaching Unit, Motor Sciences Faculty, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
- DAN Europe Research Division, 1160 Brussels, Belgium
- Correspondence: (C.B.); (F.V.); (G.B.)
| | - Kate Lambrechts
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (K.L.); (M.L.); (P.G.); (P.L.)
| | - Simona Mrakic-Sposta
- Institute of Clinical Physiology, National Research Council (IFC-CNR), Piazza dell’Ospedale Maggiore, 3, 20162 Milan, Italy; (S.M.-S.); (A.V.)
| | - Alessandra Vezzoli
- Institute of Clinical Physiology, National Research Council (IFC-CNR), Piazza dell’Ospedale Maggiore, 3, 20162 Milan, Italy; (S.M.-S.); (A.V.)
| | - Morgan Levenez
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (K.L.); (M.L.); (P.G.); (P.L.)
| | - Peter Germonpré
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (K.L.); (M.L.); (P.G.); (P.L.)
- DAN Europe Research Division, 1160 Brussels, Belgium
- Centre for Hyperbaric Oxygen Therapy, Queen Astrid Military Hospital, 1120 Brussels, Belgium
| | - Fabio Virgili
- Council for Agricultural Research and Economics—Food and Nutrition Research Centre (C.R.E.A.-AN), 00178 Rome, Italy
- Correspondence: (C.B.); (F.V.); (G.B.)
| | - Gerardo Bosco
- Environmental Physiology & Medicine Lab, Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Correspondence: (C.B.); (F.V.); (G.B.)
| | - Pierre Lafère
- Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute Ecole Bruxelles-Brabant (HE2B), 1180 Brussels, Belgium; (K.L.); (M.L.); (P.G.); (P.L.)
- DAN Europe Research Division, 1160 Brussels, Belgium
- Centre for Hyperbaric Oxygen Therapy, Queen Astrid Military Hospital, 1120 Brussels, Belgium
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