Fall from standing height, or greater, and mortality among ambulance-transported patients with major trauma from falls

Introduction: This study describes the relationship between falls from standing height, or greater, and mortality in ambulance-transported patients with major trauma from falls. Methods: Road ambulance records from 1 January 2013 to 31 December 2016 were linked with WA State Trauma Registry records to identify ambulance-transported falls patients with major trauma. Results: Of the patients who fell from standing level, 114/460 (25%) died within 30 days, compared with 47/222 (21%) who fell from height (p=0.64). Conclusion: Mortality is relatively high, and fall height is not associated with 30-day survival, among ambulance-transported patients with major trauma in metropolitan Perth, Western Australia

Hyperbaric exposure in rodents with noninvasive imaging assessment of decompression bubbles: A scoping review protocol

Hyperbaric pressure experiments have provided researchers with valuable insights into the effects of pressure changes, using various species as subjects. Notably, extensive work has been done to observe rodents subjected to hyperbaric pressure, with differing imaging modalities used as an analytical tool. Decompression puts subjects at a greater risk for injury, which often justifies conducting such experiments using animal models. Therefore, it is important to provide a broad view of previously utilized methods for decompression research to describe imaging tools available for researchers to conduct rodent decompression experiments, to prevent duplicate experimentation, and to identify significant gaps in the literature for future researchers. Through a scoping review of published literature, we will provide an overview of decompression bubble information collected from rodent experiments using various non-invasive methods of ultrasound for decompression bubble assessment. This review will adhere to methods outlined by the Joanna Briggs Institute Manual for Evidence Synthesis and be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR). Literature will be obtained from the PubMed, Embase, and Scopus databases. Extracted sources will first be sorted to a list for inclusion based on title and abstract. Two independent researchers will then conduct full-text screening to further refine included papers to those relevant to the scope. The final review manuscript will cover methods, data, and findings for each included publication relevant to non-invasive in vivo bubble imaging

Thirty years of American cave diving fatalities

INTRODUCTION: Cave divers enter an inherently dangerous environment that often includes little visibility, maze-like passageways and a ceiling of rock that prevents a direct ascent to the surface in the event of a problem.METHODS: Reports of cave diving fatality cases occurring between 01 July 1985 and 30 June 2015 collected by Divers Alert Network were reviewed. Training status, safety rules violated, relevancy of the violations, and root causes leading to death were determined.RESULTS: A total of 161 divers who died were identified, 67 trained cave divers and 87 untrained. While the annual number of cave diving fatalities has steadily fallen over the last three decades, from eight to less than three, the proportion of trained divers among those fatalities has doubled. Data regarding trained cave divers were divided into two equal 15-year time periods. Trained cave divers who died in the most recent time period were older but little else differed. The most common cause of death was asphyxia due to drowning, preceded by running out of breathing gas, usually after getting lost owing to a loss of visibility caused by suspended silt. An overwhelming majority of the fatalities occurred in the state of Florida where many flooded caves are located.CONCLUSION: Even with improvements in technology, the greatest hazards faced by cave divers remain unchanged. Efforts to develop preventative interventions to address these hazards should continue

Ten years of recreational diving fatalities in the United States and Canada: harvesters vs non-harvesters

© International Society of Travel Medicine, 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: [email protected]. Adult male recreational diver fatalities (n = 698) in North America from 2004 to 2013 were examined. Compared with non-harvesters, boat (86 vs 59%), solo (26 vs 13%) and night diving (10 vs 3%) were more common among harvesters. Of the divers who were low-on or out-of air, 20% were harvesters and 11% non-harvesters (OR?=?2.0, P = 0.03)

Possible central nervous system oxygen toxicity seizures among US recreational air or enriched air nitrox open circuit diving fatalities 2004–2013

© 2017 Taylor & Francis Group, LLC. Background: The first diver certification programme for recreational ‘enriched air nitrox’ (EAN) diving was released in 1985. Concerns were expressed that many EAN divers might suffer central nervous system (CNS) oxygen toxicity seizures and drown. Methods: US fatalities on open-circuit scuba occurring between 2004–2013, where the breathing gas was either air or EAN, were identified. Causes of death and preceding circumstances were examined by a medical examiner experienced in diving autopsies. Case notes were searched for witnessed seizures at elevated partial pressures of oxygen. Results: The dataset comprised 344 air divers (86%) and 55 divers breathing EAN (14%). EAN divers’ fatal dives were deeper than air divers’ (28 msw vs 18 msw, p < 0.0001). Despite this, of the 249 cases where a cause of death was established, only three EAN divers were considered to have possibly died following CNS oxygen toxicity seizures at depth (ppO2 132, 142 and 193 kPa). Conclusion: The analysis of recreational diving fatalities in the US over 10 years found just one death likely from CNS oxygen toxicity among EAN divers. A further two possible, although unlikely, cases were also found. Fears of commonplace CNS oxygen toxicity seizures while EAN diving have not apparently been realized

Risk factors for cardiovascular disease among active adult US scuba divers

Cardiovascular factors among uninjured active adult recreational scuba divers in the USA are described. Scuba diving as an activity was included in 2011, 2013, and 2015 Behavioral Risk Factor Surveillance System data. One-third of active US scuba divers were aged =50 years and/or reported prior high cholesterol, around half were overweight, more than half reported having smoked cigarettes, and 32% reported hypertension or borderline hypertension. High cholesterol, hypertension, high body mass index, and smoking status should all be addressed during routine diving fitness physician assessments, to reduce the risk of mortality while diving

Epidemiology of morbidity and mortality in US and Canadian recreational scuba diving

© 2017 The Royal Society for Public Health Objectives: This study investigates morbidity and mortality suffered by divers in the USA and Canada. Study design: Prospectively recruited probability-weighted sample for estimating the national burden of injury and a weighted retrospective survey for estimating exposure. Methods: The National Electronic Surveillance System and Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were searched for scuba diving injuries. The Divers Alert Network diving fatality database was searched for deaths, and Sports and Fitness Industry Association estimates for diving were obtained from annual surveys. Results: In the USA, there were an estimated 1394 emergency department (ED) presentations annually for scuba-related injuries. The majority (80%) were treated and/or released. There were an estimated 306 million dives made by the US residents 2006–2015 and concurrently 563 recreational diving deaths, a fatality rate of 0.18 per 105 dives and 1.8 per 105 diver-years. There were 658 diving deaths in the US 2006–2015 and 13,943 ED presentations for scuba injuries, giving a ratio of 47 diving deaths in the USA for every 1000 ED presentations. There were 98 cases of scuba-related injuries identified in the CHIRPP data. The prevalence of scuba-related injuries for patients aged 3–17 years was 1.5 per 105 cases, and the prevalence of scuba-related injuries to patients 18–62 years was 16.5 per 105 cases. Discussion: In Canada and the USA, only one out of every 10,000 ED presentations is due to a scuba-related injury. That there are 47 deaths for every 1000 ED presentations for scuba injuries speaks to the relatively unforgiving environment in which scuba diving takes place. For 1.8 deaths per million recreational dives, mortality in scuba diving is nonetheless relatively low

Theoretical tissue compartment inert gas pressures during a deep dive with and without deep decompression stops: a case analysis.

BACKGROUND: Deep decompression stops are increasingly common in recreational technical diving. Concerns exist that they shift decompression stress back into slower tissues. A diver recorded an exceptional exposure dive, with deeps stops, on a commercially available dive computer. MATERIAL AND METHODS: Using the R package SCUBA tissue inert gas pressures in 17 Bühlmann (ZH-L16A) compartments were estimated from the dive computer recorded profile. The RGBM dive plan generated by the diver's software was similarly interrogated, as was a third profile with reduced deep stops generated using the VPM-B/E model. RESULTS: In this dive the combination of 5 gas switches appeared to ameliorate the effect of deep stops from 76 m depth. CONCLUSIONS: A higher-than-anticipated inert gas content in a decompression mixture, coupled with climbing 200 stairs post-decompression, appear possible risk factors for decompression sickness. Nonetheless, the physiological effect of deep decompression stops during exceptional exposure, even when diving with gas switches, remains urgently to be determined to improve safe decompression following exceptional exposures. Until algorithms utilising deep decompression stops are validated with human data, dive profiles incorporating deep decompression stops should be considered experimental

Evidence of Heritable Determinants of Decompression Sickness in Rats

Introduction Decompression sickness (DCS) is a complex and poorly understood systemic disease caused by inadequate desaturation after a decrease of ambient pressure. Strong variability between individuals is observed for DCS occurrence. This raises questions concerning factors that may be involved in the interindividual variability of DCS occurrence. This study aimed to experimentally assess the existence of heritable factors involved in DCS occurrence by selectively breeding individuals resistant to DCS from a population stock of Wistar rats. Methods Fifty-two male and 52 female Wistar rats were submitted to a simulated air dive known to reliably induce about 63% DCS: compression was performed at 100 kPa·min-1up to 1000 kPa absolute pressure before a 45-min long stay. Decompression was performed at 100 kPa·min-1with three decompression stops: 5 min at 200 kPa, 5 min at 160 kPa, and 10 min at 130 kPa. Animals were observed for 1 h to detect DCS symptoms. Individuals without DCS were selected and bred to create a new generation, subsequently subjected to the same hyperbaric protocol. This procedure was repeated up to the third generation of rats. Results As reported previously, this diving profile induced 67% of DCS, and 33% asymptomatic animals in the founding population. DCS/asymptomatic ratio was not initially different between sexes, although males were heavier than females. In three generations, the outcome of the dive significantly changed from 33% to 67% asymptomatic rats, for both sexes. Interestingly, survival in females increased sooner than in males. Conclusions This study offers evidence suggesting the inheritance of DCS resistance. Future research will focus on genetic and physiological comparisons between the initial strain and the new resistant population

Compact Recreational Rebreather With Innovative Gas Sensing Concept and Low Work of Breathing Loop Design

Recreational rebreathers are increasingly popular, and recreational diver training organizations now routinely offer training for rebreather diving. Few rebreathers on the market, however, fulfill the criteria of a dedicated recreational rebreather. These remain based on traditional sensor technology, which may be linked to rebreather use having an estimated 10 times the risk of mortality while diving compared with open circuit breathing systems. In the present work, a new recreational rebreather based on two innovative approaches is described. Firstly the rebreather uses a novel sensor system including voltammetric and spectroscopic validation of galvanic pO(2) sensor cells, a redundant optical pO(2) sensor, and a two-wavelength infrared pCO(2) sensor. Secondly a new breathing loop design is introduced, which reduces failure points improves work of breathing, and can be mass fabricated at a comparatively low cost. Two prototypes were assembled and tested in the laboratory at a notified body for personal protective equipment before both pool and sea water diving trials. Work of breathing was well below the maximum allowed by the European Normative. These trails also demonstrated that optical pO(2) sensors can be successfully employed in rebreathers. The pCO(2) sensor defected pCO(2) from 0.0004 to 0.0024 bar. These new approaches, which include a new concept for simplified mechanical design as well as improved electronic control, may prove useful in future recreational diving apparatus