Abstract:
:Inner-ear decompression sickness (DCS) is an incompletely understood and increasingly recognized condition in compressed-air divers. Previous reports show a high association of inner-ear DCS with persistent foramen ovale (PFO), suggesting that a moderate-to-severe right-to-left shunt might represent a major predisposing factor, and more properly defining it as an event from arterial gas embolism (AGE). However, other conditions characterized by bubbles entering the arterial circulation, such as open-chamber cardiac surgery, do not produce inner-ear involvement, while sometimes damaging the brain extensively. Moreover, in other sites, such as the spinal cord, the prevailing mechanism for DCS is not AGE, but more likely local bubble formation with subsequent compression of venules and capillaries. Thus, AGE might be, more properly, a predisposing condition, neither sufficient, nor possibly even strictly necessary for inner-ear DCS. A 'two-hit hypothesis' has been proposed, implying a locally selective vulnerability of the inner ear to AGE. Modelled kinetics for gas removal are slower in the inner ear compared to the brain, leading to a supersaturated environment which allows bubbles to grow until they eventually obstruct the labyrinthine artery. Since this artery is relatively small, there is a low probability for a bubble to enter it; this might explain the disproportion between the high prevalence of PFO in the general population (25-30%) and the very low incidence of inner-ear DCS in compressed-air diving (approximately 0.005%). Furthermore, given that the labyrinthine artery usually originates either from the anterior inferior cerebellar artery, or directly from the basilar artery, shunting bubbles will more frequently swarm through the entire brain. In this case, however, the brain's much faster gas removal kinetics might allow for them to be reabsorbed without damaging brain tissue. In line with this scenario is the low probability (approx. 15%) of inner-ear DCS presenting with concomitant symptoms suggestive of brain involvement. Interestingly, PFO is a putative risk factor not only for DCS but also for ischaemic stroke, and it has been hypothesized that a predominantly silent ischaemic cerebral burden might represent a meaningful surrogate of end-organ damage in divers with PFO, with implications for stroke or cognitive decline. Here we report the case of a 44-year-old diving instructor (> 350 dives) who suffered from inner-ear DCS about 10 min after a routine dive (5 min/40 metres' fresh water (mfw), ascent 7.5 mfw·min⁻¹, stop 10 min/5 mfw), resulting in severe left cochlear/vestibular impairment (complete deafness and marked vertigo, only the latter slowly receding after a few hours). The patient was not recompressed. A few months later, transcranial Doppler ultrasonography demonstrated a moderate-to-severe shunt (> 30 bubbles), presumably due to a PFO (he refused confirmatory echocardiography), while a brain MRI (1.5 T) was reported as negative for both recent and remote lacunar infarcts (Figure 1). We believe this may be evidence that inner-ear DCS could occur while the brain is completely spared, not only clinically, but also at neuroimaging. This would support either of two hypotheses: (a) that the brain is indeed relatively protected from arterial bubbles that preferentially harm the inner ear where, however, they only rarely infiltrate, or (b) that direct bubble formation within the inner ear cannot be completely discarded, and that the elevated PFO-inner-ear DCS association might be, in this latter case, merely circumstantial. We favour the hypothesis that inner-ear DCS might be related to AGE in an anatomically vulnerable region. More precise data regarding the exact incidence of inner-ear involvement, isolating those subjects with moderate-to-severe shunt, should be obtained before exploring the risk-to-benefit ratio given by transcatheter occlusion of a PFO for prevention of inner-ear DCS; odds that could end up to be sensibly different with respect to other types of DCS presentation.
journal_name
Diving Hyperb Medjournal_title
Diving and hyperbaric medicineauthors
Tremolizzo L,Malpieri M,Ferrarese C,Appollonio Isubject
Has Abstractpub_date
2015-06-01 00:00:00pages
135-6issue
2eissn
1833-3516issn
2209-1491journal_volume
45pub_type
信件abstract:INTRODUCTION:An individual case review of diving-related deaths reported as occurring in Australia in 2006 was conducted as part of the Divers Alert Network Asia-Pacific (DAN AP) dive fatality reporting project. METHOD:The case studies were compiled using reports from witnesses, the police and coroners. In each case, ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2011-06-01 00:00:00
abstract:INTRODUCTION:Running out of air, buoyancy problems and rapid ascents are known risk factors for diving morbidity and mortality. The effects of the diving environment and equipment and the influence of individual diver characteristics on these risks were studied. METHODS:Between 1995 and 2004, Project Dive Exploration ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2009-12-01 00:00:00
abstract:INTRODUCTION:Decompression illness (DCI) is associated with a right-to-left shunt, such as persistent foramen ovale (PFO), atrial septal defect (ASD) and pulmonary arteriovenous malformations. About one-quarter of the population have a PFO, but considerably less than one-quarter of divers suffer DCI. Our aim was to det...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2015-06-01 00:00:00
abstract::It is increasingly common for recreational scuba divers to use breathing mixtures enriched with additional oxygen ('nitrox' or 'enriched air nitrogen') and for technical divers to be exposed to elevated partial pressures of oxygen for prolonged periods of time. The National Oceanic and Atmospheric Administration oxyge...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2008-06-01 00:00:00
abstract:INTRODUCTION:In-water resuscitation has recently been proposed in the European resuscitation guidelines. Initiation of mechanical ventilation underwater might be considered when an immediate ascent to the surface is impossible or dangerous. The present study evaluated the feasibility of such ventilation underwater. ME...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2013-06-01 00:00:00
abstract:INTRODUCTION:This study identified pre-existing medical conditions among scuba diving fatalities in Australia from 2001 to 2013, inclusive, and assessed whether these conditions likely contributed to the deaths. METHODS:The National Coronial Information System (NCIS) was searched for scuba diving-related cases during ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm50.2.98-104
更新日期:2020-06-30 00:00:00
abstract:INTRODUCTION:The Diver Emergency Service (DES) in Australia provides specialised medical advice on diving incidents 24 hours a day to divers, dive operators, families and health professionals. It is operated from the Hyperbaric Medicine Unit of the Royal Adelaide Hospital where the physician-on-call also carries the DE...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2012-09-01 00:00:00
abstract:INTRODUCTION:Various prescribed and over-the-counter medications may theoretically be incompatible with the diving environment. Anecdotally, it is known divers regularly take medications around the time of their diving activities for different health conditions, possibly ignoring the recommendations not to do so. As pa...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2011-03-01 00:00:00
abstract::Divers suspected of suffering decompression illness (DCI) in locations remote from a recompression chamber are sometimes treated with in-water recompression (IWR). There are no data that establish the benefits of IWR compared to conventional first aid with surface oxygen and transport to the nearest chamber. However, ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,评审
doi:10.28920/dhm48.2.84-95
更新日期:2018-06-30 00:00:00
abstract::Cerebral arterial gas embolism (CAGE) from breath-holding or inadequate exhalation during ascent is a well-recognised complication of scuba diving. It does not usually occur with breath-hold (BH) diving in those with normal lungs, as the volume of gas in the lungs on surfacing cannot exceed what it was on leaving the ...
journal_title:Diving and hyperbaric medicine
pub_type:
doi:10.28920/dhm49.4.304-305
更新日期:2019-12-20 00:00:00
abstract::Divers from many countries travel to explore various diving sites worldwide. In 2005, the Divers Alert Network (DAN) wrote guidelines for recreational diving and diabetes mellitus, but there is no up-to-date consensus or adoption of international guidelines on diabetes and diving. There are also large differences betw...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2012-12-01 00:00:00
abstract:BACKGROUND:Both negative wound pressure therapy (NPWT) and hyperbaric oxygen therapy (HBOT) are useful modalities in the treatment of problem wounds. However, none of the commercially available portable negative-pressure devices have been certified safe for use in a recompression chamber. Thus, the NPWT device is remov...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,随机对照试验
doi:
更新日期:2011-09-01 00:00:00
abstract:INTRODUCTION:We investigated in a prospective, observational trial the feasibility of using the Eustachian tube function test (ETFT) to measure the effect of repetitive pressure exposure during open seawater dives on Eustachian tube function. METHODS:The study included 28 adult divers during six consecutive days of di...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm47.4.216-222
更新日期:2017-12-01 00:00:00
abstract::Sphenoid sinus mucocele is a rare cystic lesion. It grows gradually and causes visual disturbances, ocular motility abnormalities and headache due to cavernous sinus compression. Sudden change in sinus cavity volume by a barotrauma may compress a mucocele and precipitate symptoms that may easily be confused with decom...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm50.2.168-172
更新日期:2020-06-30 00:00:00
abstract::Vomiting and aspiration of gastric contents into the airways and lungs is a common and well-known clinicopathological entity. This phenomenon might also occur in underwater diving, where it can lead to life-threatening or fatal situations. This article presents two incidents involving diving-related vomiting with asso...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm48.1.36-39
更新日期:2018-03-31 00:00:00
abstract::Exposure to hyperoxia is associated with oxidative stress and is known to cause inflammation in the lung and the airways. Exhaled nitric oxide concentration (FENO) is a marker of some inflammatory processes in the lung and airways, and is reduced immediately after a single session of hyperbaric oxygen (HBO) exposure. ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2009-06-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to further the understanding of the opening of the Eustachian tube in relation to changes in barometric pressure. DESIGN:An ear canal microphone was used to measure the specific sounds related to tube opening and possible eardrum movements. Five subjects with normal tube functio...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2016-03-01 00:00:00
abstract:INTRODUCTION:Transcutaneous oximetry measurement (TCOM) is a non-invasive method of determining oxygen tension at the skin level using heated electrodes. AIM:To compare TCOM values generated by different machines and to establish lower limb TCOM values in a cohort of healthy individuals younger than 40 years of age. ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm47.2.82-87
更新日期:2017-06-01 00:00:00
abstract::Dear Editor, By focussing on the details of the Watson case, I believe Bryan Walpole has missed the thrust of my earlier letter. I agree this was a complex case, which is why I deliberately avoided the murky specifics in order to consider the 'big-picture' ramifications of the judgement. My concerns relate to the pote...
journal_title:Diving and hyperbaric medicine
pub_type: 信件
doi:
更新日期:2011-12-01 00:00:00
abstract: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 diabe...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,随机对照试验
doi:10.28920/dhm50.4.386-390
更新日期:2020-12-20 00:00:00
abstract:INTRODUCTION:When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automaticall...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm47.3.191-197
更新日期:2017-09-01 00:00:00
abstract::A case of a 24-year-old gentleman who had pulmonary barotrauma (PBT) after diving is reported. He presented with chest pain after the second of two uneventful shallow SCUBA dives. Computerized tomography (CT) scan confirmed the diagnosis and he was treated conservatively. Relevant radiology and a discussion of PBT are...
journal_title:Diving and hyperbaric medicine
pub_type:
doi:10.28920/dhm50.1.66-69
更新日期:2020-03-31 00:00:00
abstract::Decompression illness (DCI) is a syndrome with diverse clinical manifestations but in which cardiac symptoms are rare. In the presence of cardiac symptoms, the necessity to rule out an acute coronary syndrome (ACS) which requires prompt treatment may result in delay to appropriate recompression treatment. We describe ...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2013-12-01 00:00:00
abstract::Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adapt...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,评审
doi:
更新日期:2013-09-01 00:00:00
abstract::The South Pacific Underwater Medicine Society (SPUMS) diving medical for recreational scuba divers was last reviewed in 2011. From 2011 to 2019, considerable advancements have occurred in cardiovascular risk assessment relevant to divers. The SPUMS 48th (2019) Annual Scientific Meeting theme was cardiovascular risk as...
journal_title:Diving and hyperbaric medicine
pub_type: 指南
doi:10.28920/dhm50.3.273-277
更新日期:2020-09-30 00:00:00
abstract:BACKGROUND:Since 2009, the United Kingdom diving incident data show an increasing number of fatalities in the over-50s age group. Previous studies also suggest some divers take cardiac medications. Since 2001, diving medicals have not been mandatory for UK sport divers. Instead, an annual medical self-certification for...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2015-09-01 00:00:00
abstract::In an emergency, life support can be provided during recompression or hyperbaric oxygen therapy using very basic equipment, provided the equipment is hyperbaric-compatible and the clinicians have appropriate experience. For hyperbaric critical care to be provided safely on a routine basis, however, a great deal of pre...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,评审
doi:
更新日期:2015-03-01 00:00:00
abstract:INTRODUCTION:During a hyperbaric oxygen therapy (HBOT) session, every medical device that is used within the hyperbaric chamber is exposed to several hazards, including an increased ambient pressure and partial pressure of oxygen. In Europe, all medical devices marketed and/or sold for use in hyperbaric conditions must...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:10.28920/dhm49.2.137-140
更新日期:2019-06-30 00:00:00
abstract::Divers are exposed to circulatory stress that directly affects the endothelial lining of blood vessels, and even asymptomatic dives are associated with inflammatory responses, microparticle release and endothelial dysfunction. As humans age, there is a relative increase in the risk of cardiovascular disease, attribute...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章,评审
doi:
更新日期:2015-12-01 00:00:00
abstract:INTRODUCTION:Scuba diving involves risks, and candidates in Australia usually have a medical evaluation prior to undertaking a diving course. Hyperbaric physicians act as secondary referral practitioners for these assessments. This study aimed to identify reasons for these secondary referrals, and document the assessme...
journal_title:Diving and hyperbaric medicine
pub_type: 杂志文章
doi:
更新日期:2010-09-01 00:00:00