scholarly journals Dysbaric osteonecrosis (DON) among the artisanal diving fishermen of Yucatán, Mexico

2020 ◽  
Vol 50 (4) ◽  
pp. 391-398
Author(s):  
Daniel Popa ◽  
◽  
Anthony Medak ◽  
Walter Chin ◽  
Oswaldo Huchim-Lara ◽  
...  
Keyword(s):  
Avascular Necrosis ◽  
Decompression Sickness ◽  
Compressed Air ◽  
Prevalence Rates ◽  
Wide Spread ◽  
Diving Depth ◽  
Pairwise Correlations ◽  
Grade Ii ◽  
Hyperbaric Medicine ◽  
Diving Safety

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.

Inner Ear Decompression Sickness in Sport Compressed-Air Diving

2001 ◽  
Vol 111 (5) ◽  
pp. 851-856 ◽  
Author(s):  
Zohar Nachum ◽  
Avi Shupak ◽  
Orna Spitzer ◽  
Zohara Sharoni ◽  
Ilana Doweck ◽  
...  
Keyword(s):  
Inner Ear ◽  
Decompression Sickness ◽  
Compressed Air ◽  
Inner Ear Decompression Sickness

Fatal decompression sickness in a compressed-air worker

1965 ◽  
Vol 89 (1) ◽  
pp. 319-329 ◽  
Author(s):  
W. H. Bennison ◽  
M. J. Catton ◽  
D. I. Fryer
Keyword(s):  
Decompression Sickness ◽  
Compressed Air

scholarly journals Effects of freediving on middle ear and eustachian tube function

2020 ◽  
Vol 50 (4) ◽  
pp. 350-355
Author(s):  
Moritz F Meyer ◽  
◽  
Kristijana Knezic ◽  
Stefanie Jansen ◽  
Heinz D Klünter ◽  
...  
Keyword(s):  
Eustachian Tube ◽  
Middle Ear ◽  
Cumulative Effect ◽  
Eustachian Tube Function ◽  
Diving Depth ◽  
Middle Ear Pressure ◽  
Tube Function ◽  
Hyperbaric Medicine ◽  
The Right ◽  
Peak Pressures

(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.

scholarly journals Historical Aspects of Hyperbaric Physiology and Medicine

2020 ◽  
Author(s):  
Chandrasekhar Krishnamurti
Keyword(s):  
Heart Surgery ◽  
Scientific Explanation ◽  
Decompression Sickness ◽  
Open Heart Surgery ◽  
Medical Society ◽  
Scientific Application ◽  
History Of ◽  
Cardiac Surgeon ◽  
Hyperbaric Medicine ◽  
Lung Infections

The history of hyperbaric oxygen therapy (HBOT) makes for fascinating reading. From pneumatic chambers and compressed air baths to empirical therapeutic applications during the nineteenth century, the impetus to scientific application of HBOT began in seeking solution for decompression sickness during various construction ventures. French physiologist Paul Bert’s research was pathbreaking and provided a scientific explanation on the etiology of the “bends.” In 1908, JS Haldane’s experiments recommended staged decompression and made diving safe. In 1921, OJ Cunningham employed HBOT to treat hypoxia secondary to lung infections successfully. It was cardiac surgeon Ite Boerema who put HBOT on a solid footing with his open-heart surgery results in various pediatric cardiac conditions and rightly deserved the title of father of modern-day hyperbaric medicine. From 1937 onwards, HBOT research snowballed into treating a wide variety of diseases. In 1999, the Undersea and Hyperbaric Medical Society and Food and Drug Administration recognized the value of HBOT, and this led to its becoming a major tool in the armamentarium of clinicians, either as a primary or adjunctive therapy for a spectrum of diseases.

Predicting risk of decompression sickness in humans from outcomes in sheep

1999 ◽  
Vol 86 (6) ◽  
pp. 1920-1929 ◽  
Author(s):  
Robert Ball ◽  
Charles E. Lehner ◽  
Erich C. Parker
Keyword(s):  
Animal Model ◽  
Kinetic Parameters ◽  
Body Mass ◽  
Decompression Sickness ◽  
Compressed Air ◽  
Combined Model ◽  
Scaled Model ◽  
Log Likelihood ◽  
Practical Tool ◽  
Similar Body

In animals, the response to decompression scales as a power of species body mass. Consequently, decompression sickness (DCS) risk in humans should be well predicted from an animal model with a body mass comparable to humans. No-stop decompression outcomes in compressed air and nitrogen-oxygen dives with sheep ( n = 394 dives, 14.5% DCS) and humans ( n = 463 dives, 4.5% DCS) were used with linear-exponential, probabilistic modeling to test this hypothesis. Scaling the response parameters of this model between species (without accounting for body mass), while estimating tissue-compartment kinetic parameters from combined human and sheep data, predicts combined risk better, based on log likelihood, than do separate sheep and human models, a combined model without scaling, and a kinetic-scaled model. These findings provide a practical tool for estimating DCS risk in humans from outcomes in sheep, especially in decompression profiles too risky to test with humans. This model supports the hypothesis that species of similar body mass have similar DCS risk.

AVASCULAR NECROSIS OF THE FEMORAL HEADS IN A COMPRESSED AIR WORKER

1954 ◽  
Vol 36-B (4) ◽  
pp. 606-611 ◽  
Author(s):  
R. I. McCallum ◽  
J. K. Stanger ◽  
D. N. Walder ◽  
W. D. M. Paton
Keyword(s):  
Avascular Necrosis ◽  
Compressed Air ◽  
Femoral Heads

scholarly journals Association of microparticles and neutrophil activation with decompression sickness

2015 ◽  
Vol 119 (5) ◽  
pp. 427-434 ◽  
Author(s):  
Stephen R. Thom ◽  
Michael Bennett ◽  
Neil D. Banham ◽  
Walter Chin ◽  
Denise F. Blake ◽  
...  
Keyword(s):  
Decompression Sickness ◽  
Multiple Logistic Regression Analysis ◽  
Annexin V ◽  
Neutrophil Activation ◽  
Surface Proteins ◽  
Diving Depth ◽  
Circulating Microparticles ◽  
Systemic Disorder ◽  
Von Willebrand ◽  
Willebrand Factor

Decompression sickness (DCS) is a systemic disorder, assumed due to gas bubbles, but additional factors are likely to play a role. Circulating microparticles (MPs)—vesicular structures with diameters of 0.1-1.0 μm—have been implicated, but data in human divers have been lacking. We hypothesized that the number of blood-borne, Annexin V-positive MPs and neutrophil activation, assessed as surface MPO staining, would differ between self-contained underwater breathing-apparatus divers suffering from DCS vs. asymptomatic divers. Blood was analyzed from 280 divers who had been exposed to maximum depths from 7 to 105 meters; 185 were control/asymptomatic divers, and 90 were diagnosed with DCS. Elevations of MPs and neutrophil activation occurred in all divers but normalized within 24 h in those who were asymptomatic. MPs, bearing the following proteins: CD66b, CD41, CD31, CD142, CD235, and von Willebrand factor, were between 2.4- and 11.7-fold higher in blood from divers with DCS vs. asymptomatic divers, matched for time of sample acquisition, maximum diving depth, and breathing gas. Multiple logistic regression analysis documented significant associations ( P < 0.001) between DCS and MPs and for neutrophil MPO staining. Effect estimates were not altered by gender, body mass index, use of nonsteroidal anti-inflammatory agents, or emergency oxygen treatment and were modestly influenced by divers' age, choice of breathing gas during diving, maximum diving depth, and whether repetitive diving had been performed. There were no significant associations between DCS and number of MPs without surface proteins listed above. We conclude that MP production and neutrophil activation exhibit strong associations with DCS.

scholarly journals Persistent extravascular bubbles on radiologic imaging after recompression treatment for decompression sickness: A case report

2020 ◽  
Vol 50 (4) ◽  
pp. 424-430
Author(s):  
Juan C Dapena ◽  
◽  
Corine A Lansdorp ◽  
Simon J Mitchell ◽  
◽  
...  
Keyword(s):  
Case Report ◽  
Decompression Sickness ◽  
Mechanisms Of Action ◽  
Definitive Treatment ◽  
General Belief ◽  
Persistent Symptoms ◽  
Radiologic Imaging ◽  
Us Navy ◽  
Hyperbaric Medicine ◽  
Treatment Table

(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.

Acclimatization to diving: a systematic review

2021 ◽  
Vol 03 (01) ◽  
pp. 127-147
Author(s):  
Jan Risberg ◽  
◽  
Keyword(s):  
Systematic Review ◽  
Decompression Sickness ◽  
Experimental Studies ◽  
Subjective Health ◽  
Epidemiological Studies ◽  
Compressed Air ◽  
Cochrane Library ◽  
Hyperbaric Exposure ◽  
Review Reports ◽  
Sensitizing Effect

Multiday hyperbaric exposure has been shown to reduce the incidence of decompression sickness (DCS) of compressed-air workers. This effect, termed acclimatization, has been addressed in a number of studies, but no comprehensive review has been published. This systematic review reports the findings of a literature search. PubMed, Ovid Embase, The Cochrane Library and Rubicon Research Repository were searched for studies reporting DCS incidence, venous gas embolism (VGE) or subjective health reports after multiday hyperbaric exposure in man and experimental animals. Twenty-nine studies fulfilled inclusion criteria. Three epidemiological studies reported statistically significant acclimatization to DCS in compressed- air workers after multiday hyperbaric exposure. One experimental study observed less itching after standardized simulated dives. Two human experimental studies reported lower DCS incidence after multiday immersed diving. Acclimatization to DCS has been observed in six animal species. Multiday diving had less consistent effect on VGE after hyperbaric exposure in man. Four studies observed acclimatization while no statistically significant acclimatization was reported in the remaining eight studies. A questionnaire study did not report any change in self-perceived health after multiday diving. This systematic review has not identified any study suggesting a sensitizing effect of multiday diving, and there is a lack of data supporting benefit of a day off diving after a certain number of consecutive diving days. The results suggest that multiday hyperbaric exposure probably will have an acclimatizing effect and protects from DCS. The mechanisms causing acclimatization, extent of protection and optimal procedure for acclimatization has been insufficiently investigated.

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