589 research outputs found

    Management considerations of massive hemoptysis while on extracorporeal membrane oxygenation.

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    BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is a life-saving procedure in patients with both respiratory and cardiac failure. Bleeding complications are common since patients must be maintained on anticoagulation. Massive hemoptysis is a rare complication of ECMO; however, it may result in death if not managed thoughtfully and expeditiously. METHODS: A retrospective chart review was performed of consecutive ECMO patients from 7/2010-8/2014 to identify episodes of massive hemoptysis. The management of and the outcomes in these patients were studied. Massive hemoptysis was defined as an inability to control bleeding (\u3e300 mL/day) from the endotracheal tube with conventional maneuvers, such as bronchoscopy with cold saline lavage, diluted epinephrine lavage and selective lung isolation. All of these episodes necessitated disconnecting the ventilator tubing and clamping the endotracheal tube, causing full airway tamponade. RESULTS: During the period of review, we identified 118 patients on ECMO and 3 (2.5%) patients had the complication of massive hemoptysis. One case was directly related to pulmonary catheter migration and the other two were spontaneous bleeding events that were propagated by antiplatelet agents. All three patients underwent bronchial artery embolization in the interventional radiology suite. Anticoagulation was held during the period of massive hemoptysis without any embolic complications. There was no recurrent bleed after appropriate intervention. All three patients were successfully separated from ECMO. CONCLUSIONS: Bleeding complications remain a major issue in patients on ECMO. Disconnection of the ventilator and clamping the endotracheal tube with full respiratory and cardiac support by V-A ECMO is safe. Early involvement of interventional radiology to embolize any potential sources of the bleed can prevent re-hemoptysis and enable continued cardiac and respiratory recovery

    Spatial variability of nitrous oxide flux measurements at the plot, field and farm scale

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    Nitrous oxide (N2O) is a potent greenhouse gas (GHG) which is released naturally into the atmosphere as a by-product of the microbial processes of nitrification and denitrification. Agricultural activities are believed to account for up to 80% of anthropogenic N2O emissions at a global scale; however, these estimates are prone to large uncertainties due to the large temporal and spatial variability associated with flux measurements. This thesis contains five studies which aimed to improve the ability to measure and predict N2O emissions from agricultural activities. A closed loop dynamic chamber was developed using a quantum cascade laser (QCL). This method provided high precision chamber measurements of N2O flux from soils with a detection limit below 4 μg N2O-N m-2 h-1. Using the dynamic chamber method allowed for a detailed investigation of uncertainties in individual measurements including contributions from regression fitting, temperature and pressure. The lack of negative fluxes measured that were outwith the detection limits of the methodology (0.3% of all measurements) highlighted that the uptake of N2O reported in some previous literature is likely to have been the result of detection limits of measurement methods applied. Spatial variability of N2O flux was investigated at the plot, field and farm scale. Fluxes were measured from a grassland field plot before and after a tillage event. These measurements highlighted the large spatially variability present in N2O fluxes from agricultural soils. Fluxes varied by up to three orders of magnitude over distances less than 5 metres after the tillage event. A field scale experiment carried out on grazed grassland investigated relationships between soil properties and N2O flux. This study found that N2O emissions correlated strongly with available nitrogen content in the soil and that animal waste was likely responsible for the spatial variability of N2O flux observed at the field scale. A farm scale inventory of N2O emissions was carried out investigating several large point sources of N2O and emissions from the wider field coverage. The inventory estimates that nitrogen fertiliser application is the single largest N2O source from the livestock farm accounting for 49% of annual emissions

    Massive haemoptysis on veno-arterial extracorporeal membrane oxygenation.

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    A 49-year old female presented with severe heart failure with end-organ dysfunction and was placed on veno-arterial extracorporeal membrane oxygenation (ECMO) as a bridge to a decision for end-organ recovery. While on ECMO, the patient developed massive haemoptysis after a Swan-Ganz catheter manipulation. The haemoptysis was not controllable by conventional methods including bronchoscopy with cold saline and epinephrine lavage, bronchial blocker or angiography. The endotracheal tube was clamped to provide tamponade and the patient relied on full ECMO support for 36 h. After the haemoptysis resolved, the endotracheal tube was unclamped. The patient developed adult respiratory distress syndrome and was ventilated using the ARDSnet protocol with continued support from ECMO. On post-ECMO day 20, the patient underwent a successful ECMO wean and a Heart Mate II left ventricular assist device placement

    Nitrous oxide emission factors of mineral fertilisers in the UK and Ireland: a Bayesian analysis of 20 years of experimental data

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    In this study, we analysed datasets of N2O emission factors (EFs) from 21 separate studies carried out on arable and managed grasslands across the UK and Ireland over the past 20 years. A total of 641 separate events were collated from 40 experimental field sites. Individual EFs ranged over an order of magnitude (0–12% of applied N) for each fertiliser type, following a log-normal distribution in all cases. Our study shows that a Bayesian approach can provide a robust statistical method that is capable of performing uncertainty analysis on log-normal distributed data in a more defensible manner than conventional statistical methods allow. This method allowed for a national scale comparison of EFs between the most commonly applied mineral fertilisers based solely on previously published data (UK and Ireland in this case). The study shows that ammonium nitrate (AN) and Calcium ammonium nitrate (CAN) are the largest emitting fertiliser types by mass across the British Isles (temperate climate zone), with EFs of 1.1 (1.0–1.2) % and 1.0 (0.7–1.3) % for all recorded events, respectively; however, emissions from AN applications were significantly lower for applications to arable fields (0.6%) than to grasslands (1.3%). EFs associated with urea (CO(NH₂)₂) were significantly lower than AN for grasslands with an EF of 0.6 (0.5–0.7) %, but slightly higher for arable fields with an EF of 0.7 (0.4–1.4) %. The study highlights the potential effectiveness of microbial inhibitors at reducing emissions of N2O from mineral fertilisers, with Dicyandiamide (DCD) treated AN reducing emissions by approximately 28% and urea treated with either DCD or N-(n)-butyl) thiophosphorictriamide (NBTP) reducing emissions by approximately 40%. Although limited by a relatively small sample size (n = 11), urea treated with both DCD and NBPT appeared to have the lowest EF of all treatments at 0.13 (0.08–0.21) %, highlighting the potential to significantly reduce N2O emissions at regional scales if applied instead of conventional nitrogen fertilisers

    CEA systems: the means to achieve future food security and environmental sustainability?

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    As demand for food production continues to rise, it is clear that in order to meet the challenges of the future in terms of food security and environmental sustainability, radical changes are required throughout all levels of the global food system. Controlled Environment Agriculture (CEA) (a.k.a. indoor farming) has an advantage over conventional farming methods in that production processes can be largely separated from the natural environment, thus, production is less reliant on environmental conditions, and pollution can be better restricted and controlled. While output potential of conventional farming at a global scale is predicted to suffer due to the effects of climate change, technological advancements in this time will drastically improve both the economic and environmental performance of CEA systems. This article summarizes the current understanding and gaps in knowledge surrounding the environmental sustainability of CEA systems, and assesses whether these systems may allow for intensive and fully sustainable agriculture at a global scale. The energy requirements and subsequent carbon footprint of many systems is currently the greatest environmental hurdle to overcome. The lack of economically grown staple crops which make up the majority of calories consumed by humans is also a major limiting factor in the expansion of CEA systems to reduce the environmental impacts of food production at a global scale. This review introduces the concept of Integrated System CEA (ISCEA) in which multiple CEA systems can be deployed in an integrated localized fashion to increase efficiency and reduce environmental impacts of food production. We conclude that it is feasible that with sufficient green energy, that ISCEA systems could largely negate most forms of environmental damage associated with conventional farming at a global scale (e.g., GHGs, deforestation, nitrogen, phosphorus, pesticide use, etc.). However, while there is plenty of research being carried out into improving energy efficiency, renewable energy and crop diversification in CEA systems, the circular economy approach to waste is largely ignored. We recommend that industries begin to investigate how nutrient flows and efficiencies in systems can be better managed to improve the environmental performance of CEA systems of the future

    The impact of atmospheric N deposition and N fertilizer type on soil nitric oxide and nitrous oxide fluxes from agricultural and forest Eutric Regosols

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    Agricultural and forest soils with low organic C content and high alkalinity were studied over 17 days to investigate the potential response of the atmospheric pollutant nitric oxide (NO) and the greenhouse gas nitrous oxide (N2O) on (1) increased N deposition rates to forest soil; (2) different fertilizer types to agricultural soil and (3) a simulated rain event to forest and agricultural soils. Cumulative forest soil NO emissions (148–350 ng NO-N g−1) were ~ 4 times larger than N2O emissions (37–69 ng N2O-N g−1). Contrary, agricultural soil NO emissions (21–376 ng NO-N g−1) were ~ 16 times smaller than N2O emissions (45–8491 ng N2O-N g−1). Increasing N deposition rates 10 fold to 30 kg N ha−1 yr−1, doubled soil NO emissions and NO3− concentrations. As such high N deposition rates are not atypical in China, more attention should be paid on forest soil NO research. Comparing the fertilizers urea, ammonium nitrate, and urea coated with the urease inhibitor ‘Agrotain®,’ demonstrated that the inhibitor significantly reduced NO and N2O emissions. This is an unintended, not well-known benefit, because the primary function of Agrotain® is to reduce emissions of the atmospheric pollutant ammonia. Simulating a climate change event, a large rainfall after drought, increased soil NO and N2O emissions from both agricultural and forest soils. Such pulses of emissions can contribute significantly to annual NO and N2O emissions, but currently do not receive adequate attention amongst the measurement and modeling communities

    ‘I Am Deadly’ project evaluation December 2022

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    CERC (formally CERG) evaluated the implementation of the ‘I Am Deadly’ project, which is a version of the ‘I Am Ready’ project targeting young Aboriginal students. The project aimed at encouraging up to 20 Aboriginal students to take up a trade and providing them with a pathway into a trade. It also aimed to encourage Aboriginal Students to continue their education to allow a greater choice for employment options post-secondary school

    A survey of heavy metal contents of rural and urban roadside dusts: comparisons at low, medium and high traffic sites in Central Scotland

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    Roadside dust can contain particulates enriched with potentially toxic elements (PTEs) as a result of the degradation of mechanical vehicular parts, tyre wear and combustion processes. To assess the potential accumulation of these metals in roadside areas, a snapshot study was carried out, investigating metal content at rural and urban locations in central Scotland. Samples of road dust were collected at six sites representing low, medium and high traffic intensity at rural and urban locations. The samples were separated based on particle size and analysed for heavy metal content using inductively coupled plasma optical emission spectroscopy (ICP-OES) after acid digestion. The metals analysed were aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), lead (Pb) and zinc (Zn). The rural area measurements were carried out in West Lothian, approximately 13 to 17 miles west of the city of Edinburgh (UK). The urban area measurements were carried out in the southern part of the Edinburgh city district (UK). Concentrations of Cu, Cr and Zn were found to correlate with traffic intensity, although only Cu and Zn concentrations exceed recommended EC directive 86/278/EEC guidelines for urban runoff materials. The metal concentrations of small particles (0.45–20 μm) were exceedingly high in both Cu and Zn at areas of high traffic intensity, indicating potential areas of concern regarding health impacts for pedestrians and cyclists who are exposed to roadside dust on a regular basis
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