Reduction In Discharge Research Articles

Subaqueous Topographic Deformation in Abandoned Delta Lobes—A Case Study in the Yellow River Delta, China

Reduction in river discharge and sediment load has left deltaic lobes in the world’s many river deltas starving, but knowledge of how the subaqueous topography of these abandoned subdeltas responds to environmental changes is limited. In this study, we aimed to determine the long-term dynamics of the subaqueous seabed of abandoned delta lobes to advance current knowledge. As a case study, we selected an abandoned subdelta on the Yellow River Delta of the Bohai Sea, China, for which three-decade long (1984–2017) bathymetric data and long-term river discharge and sediment load records are available. We analyzed the seafloor surface change and quantified the void space from the sea water surface to the seafloor. In addition, we surveyed the seafloor surface with an M80 unmanned surface vehicle carrying a multibeam echo sounder system (MBES) in 2019 to obtain high-resolution microtopography information. We found that a net volume of 5.3 × 108 m3 of sediment was eroded from the study seabed within an area of 3.6 × 108 m2 during 1984–2017. This volumetric quantity is equivalent to 6.89 billion metric tons of sediment, assuming a bulk density of 1.3 t/m3 for the seabed sediment. The seabed erosion from 0 to −5 m, from −5 to −10 m, and below −10 m has showed a similar increasing trend over the past 33 years. These findings suggest that seabed erosion in this abandoned subdelta will very likely continue, and that other abandoned delta lobes in the world may have been experiencing similar seabed erosion due to the interruption of the sediment supply and sea level rise. It is not clear if the seabed erosion of abandoned delta lobes would have any effect on the stability of the coastal shoreline and continental shelf.

Human activities have more impacts on the recent discharge reduction of the largest tributary of the Yellow River relative to last three centuries

How to quantitatively decouple the impacts of climate change and human activities on river discharge changes is a challenge in current global change research. As the largest tributary of the Yellow River (YR), the Weihe River (WR) is a typical river whose discharge is influenced by climate change and human activities. Here, we first attempt to obtain the normal-flow season and high-flow season discharge in the lower reaches of the WR by using tree rings and historical documents, respectively. The relationship between natural discharge in the two seasons is unstable and complex since 1678. Using an innovative method, we reconstructed the natural discharge from March to October (DM-O), which explains >73 % of the variance in the observed DM-O during the modeling period 1935–1970. There were 44 high-flow years, 6 extremely high-flow years, 48 low-flow years and 8 extremely low-flow years from 1678 to 2008. The contribution of WR annual discharge to the YR is 17 % over the past three centuries, and their natural discharge changes synchronously rise and fall. Human activities, such as the construction of reservoirs and check-dams, agricultural irrigation and domestic and industrial water consumption, have more impacts than climate change on the decrease in the observed discharge. In total, 53.5 % of the discharge reduction since 1971 is due to human activities, and 46.5 % is due to climate change. In addition, this study provides an important model for how to quantify the influences of human activities and nature on discharge reduction and to reconstruct seasonal resolution climate in global change studies.

Effects of oral prednisolone and fluticasone nasal spray in the management of chronic rhinosinusitis with polyposis: A prospective observational study

To study the effects of combination therapy with oral prednisolone and topical fluticasone propionate nasal spray in patients with Chronic Rhinosinusitis with Nasal Polyposis (CRSwNP). To study the improvement in symptom scores, Endoscopic and CT scores before and after treatment with combination therapy.This prospective observational study was conducted on 50 patients attending the Outpatient Department of Otorhinolaryngology, J.L.N Hospital and Research Centre, Bhilai (Chhattisgarh), India over a period of 6 months from February 2020 to July 2020. Patients with symptoms of CRSwNP persisting for more than 12 weeks were thoroughly examined clinically along with Nasal endoscopy and Computed Tomography scan of Nose and Paranasal sinuses (CT PNS) and pre-treatment Visual Analog Scale (VAS), Lund & Mackay Scores for Endoscopic and CT findings were noted. Patients were treated with combination therapy of oral prednisolone and fluticasone propionate nasal spray and post treatment scores were noted using similar scales during the follow up visits and the results were statistically analysed.Total mean age of patients suffering from CRSwNP in our study was 47.3 ± 12.58. Males were affected more by CRSwNP than females (76% vs 24%). At the end of 3 months from baseline 48 patients (96%) showed a reduction in nasal discharge, 47 patients (94%) showed a reduction in nasal obstruction, 25 patients (50%) showed improvement in facial pain and 17 patients (34%) showed improvement in hyposmia. Overall post treatment Visual Analog Symptom (VAS) score improved in 42 patients (84%), Nasal endoscopy (Lund - Mackay scoring) improved in 43 patients (86%) and Radiological CT PNS & Nose (Lund - Mackay Scoring) improved in 33 patients (66%).We found that combined therapy with oral prednisolone and fluticasone propionate nasal spray for 3 weeks is very effective in reducing the symptoms of chronic rhinosinusitis along with decrease in nasal secretions, edema and polyp size.

The assessment of drainage performance in the residential area using SWMM

Flood is a general issue that can lead to the life and safety of residents. One of the problems is the lack of capacity in the drainage system in a residential area. This paper will analyze the drainage system based on the capacity in one of the residential clusters. The method for the drainage system performance in hydrology analysis was carried out with Log Person, and the return period for rainfall duration is ten years (R10) for hydraulic analysis using drainage system modeling with EPA – SWMM 5.1. The result based on hydrological is the precipitation for flood forecasting is 159.79 mm. It is found that the drainage capacity is filled in downstream of the main drain with a maximum discharge of 2.726 m3/s and secondary drains with a maximum discharge of 0.624 m3/s. Improvements were made to resolve the insufficiency of the existing channels by running two different scenarios: (1) Re-design the dimensions of the main and secondary channels, (2) Implement a detention pond, as well as re-design the dimensions of the secondary channels. Both scenarios could overcome the flood problem. Scenario 2 shows a higher reduction in the flow discharge at the downstream channel compared to scenario 1.

Identifying the water quality variation characteristics and their main driving factors from 2008 to 2020 in the Yellow River Basin, China.

Understanding of the water quality dynamics and their main influence factors is crucial for sustainable water environment management especially in the sensitive ecosystem area. Here, the spatiotemporal dynamic of water quality in the Yellow River Basin from 2008 to 2020 and its relationship with physical geography, human activities, and meteorology were studied by using Pearson correlation test, and a generalized linear model. The results showed that water quality was significantly improved since 2008, which was reflected from the decreasing trend of the permanganate index (CODMn) and ammonia nitrogen (NH3-N), and increasing trend of the dissolved oxygen (DO). However, the total nitrogen (TN) remained severely polluted with average annual concentration inferior to level V. Spatially speaking, the water quality in the upper and lower reaches was better than that of the middle reaches. The whole basin was severely contaminated by TN with 2.62 ± 1.52, 3.91 ± 1.71, and 2.91 ± 1.20mg L-1 from upper, middle, and lower reaches, respectively. Thus, TN should be paid much attention in the water quality management of the Yellow River Basin. The water quality improvement could be attributed to the reduction of pollution discharges and ecological restoration. Further analysis found the variation of water consumption and increase of forest and wetland area contributed 39.90% and 47.49% for CODMn and 58.92% and 30.87% for NH3-N, respectively. Meteorological variables and total water resources contributed slightly. This study is expected to provide in-depth insights for the water quality dynamics and their response to human activities and natural factors in the Yellow River Basin, which could provide theoretical references for water quality protection and management.

Impact of Paddy Field Reservoirs on Flood Management in a Large River Basin of Japan

The flood retention capacity of paddy fields is well-recognized in Japan, and all the existing flood control practices via paddy field management achieve reductions in peak flood discharge. However, the previous studies have not assessed the flood management potential of paddy fields in a large river basin with average paddy coverage, and the existing hydrological models are not quite suitable for simulating river discharge from closed-drainage paddy reservoir storage. We herein attempt to improve the watershed-scale version of global hydrological model H08 to simulate a reduction in the peak discharge from paddy reservoirs in the Abukuma River basin of Japan. The NSE and R2 index showed fair reliability of the H08 model during the calibration and validation stages. The simulated results from the improved model show 11% and 6% peak reductions in high paddy coverage areas for a normal year (2018) and a major typhoon year (2019), respectively. The peak-reduction percentage increased with decreasing rainfall, depending on the overflow from the paddy reservoirs. The results indicate that the paddy reservoir is not highly effective in a large river with less than 20% paddy coverage, but the peak discharge reduction capacity shows that paddy reservoirs can make some contribution when used in combination with dam operation.

A clean two-stage Bayer process for achieving near-zero waste discharge from high-iron gibbsitic bauxite

The current Bayer process focused on alumina extraction without considering the comprehensive utilization of other valuable components, such as iron, and the resulting red mud caused severe ecological and environmental safety risks. This work proposed a clean two-stage Bayer digestion technology to obtain iron-rich red mud with low Na2O content from high-iron gibbsitic bauxite processing. The effects of digestion conditions on alumina extraction rate and iron enrichment degree in red mud were studied systematically. The ICP, XRD, SEM, and TEM were used to investigate the chemical compositions, phase structures and microstructures of bauxite and red mud. Results show that approximately 83% Al2O3 was extracted, and about 43% SiO2 was separated simultaneously in gibbsitic bauxite in the first stage, whereas undigested aluminum-bearing minerals mainly originated from substituted aluminum in goethite. Hydrogen was produced by the reaction of glycerol with sodium aluminate solution in the second stage, which promoting the reaction of Al-goethite with titanium-bearing minerals to form Fe(Ⅱ) and Ti(Ⅳ)-substituted hematite. The increase in reductants amount, caustic alkali concentration, reaction temperature, and time favored Al-goethite transformation in digestion. The total Al2O3 recovery and the Fe2O3 in red mud could reach more than 99% and 86%, respectively. Moreover, the content of Al2O3, SiO2, and Na2O in red mud satisfied the iron ore concentrate standard of GB/T 36704-2018, which was attributed to avoiding the generation of desilication products (DSP) in red mud. The 93% silicon could be removed from the liquid phase by two separations of the digested slurry. This work will facilitate the large-scale reduction of red mud discharge through further the value-added use of novel red mud technology in collaboration with steel and aluminum, achieving the green and sustainable development of the alumina industry.

Laboratory Investigation Into the Effect of the Storage Capacity of a City Block on Unsteady Urban Flood Flows

AbstractThe increasing occurrence of urban flooding in recent years demands a more accurate flood hazard assessment. Therefore, a better understanding of the predominant hydraulic processes in urban flood flows is required. The present paper reports an experimental study conducted in a laboratory scale model, which represents an urban area consisting of a rectangular city block and four surrounding streets. The objective is to quantify the impact of open areas within the city block on the key features of floodwaters. Tests are carried out under unsteady flow conditions, by using three inflow hydrographs with different unsteadiness levels. For each inflow hydrograph, the space available for floodwater volume storage within the block (storage capacity, ϕ) is varied, keeping the boundary conditions unchanged. A case where the city block has no space for floodwater storage (i.e., ϕ = 0) is used as a reference case. The results indicate that the unsteadiness level of the inflow hydrograph, especially during the rising stage, has a strong influence on the floodwater volume stored within the city block. The increase in storage capacity within the city block leads to a reduction of the global peak outflow discharge, a decrease in flow depths and a local increase in velocities in some streets and within the city block. Finally, with these variations in floodwater features, the level of risk to pedestrians is also impacted, increasing locally when the storage capacity of the block increases.

Method for establishing soil contaminant discharge inventory: An arsenic-contaminated site case study

The existing method to survey site pollution is generally based on soil-groundwater sampling and instrumental analysis, which enables us to access the detailed soil pollution status while lacking quantitative association with industrial activities. It is urgent to understand contaminant discharge modes and establish a discharge inventory for achieving process-targeted pollution control. This study took a 40-year phosphate fertilizer-sulfuric acid site as an example and constructed a contaminant tracing method based on on-site investigations and detailed industrial data. These investigations and data were combined to determine the characteristic pollutant of this site, arsenic. And the calculation process of four-pathway pollution modes (atmospheric deposition, wastewater, solid waste leaching, and storage dripping) is derived from the existing acceptance criteria and risk assessment guidelines. They are set to calculate the arsenic's factory-to-soil discharge flux. The absent process contaminant release information and parameters, such as discharge coefficient, were obtained from soil-groundwater pollution control standards and discharge handbooks. It was found that the high concentration of arsenic (around 1930 mg g−1) was preponderantly caused by sulfur-iron slag and tailing leaching (96.19%), while the other pathways accounted for only 0.13% (atmospheric deposition), 3.59% (wastewater) and 0.09% (storage tank). Results were verified by the measured arsenic concentration, and the difference was +16.29%, which was acceptable. Finally, a contaminant discharge inventory was established with high-resolution spatial distribution and time-scale (historical discharge) evolution. The innovation of this study lies in the preliminary construction of a method for formulating soil discharge inventory. This study would contribute to the refined management of site pollution and reduction of source contaminants discharge. In addition, it will help infer the pollution condition of sites that are difficult to sample so as to help the government achieve precise source control.

Impact of New York State's Health Home Model on Health Care Utilization.

The Affordable Care Act established Medicaid health homes to provide care management and coordination for high-need individuals, including many with serious mental illness. The authors used data from the Medicaid Data Warehouse to examine health care utilization over 3 years among 10,193 individuals who enrolled in a New York State health home and had at least one outpatient mental health visit during the year prior to enrollment. Results for postenrollment year 2 indicated a 43% decrease in inpatient mental health discharges, a 38% decrease in substance use discharges, and a 7% reduction in general medical discharges, whereas mental health outpatient treatment and behavioral and nonbehavioral medication utilization increased. Further research is needed to determine the effectiveness of health home care management for individuals with serious mental illness.

Evaluation of Wastewater Discharge Reduction Scenarios in the Buenaventura Bay

Buenaventura Bay is facing severe pollution due to the direct discharge of untreated wastewater from 695 outlets along the coast, which serves 500,000 people. To address this issue, a study was conducted using the RMA11 water quality model, which was previously calibrated and validated, coupled with the RMA10 3D hydrodynamic model to assess sanitation scenarios in the bay. Five effluent reduction scenarios were proposed and compared based on fecal coliform concentration as an indicator, with evaluation also based on areas where fecal coliform concentrations exceeded the standard for primary contact. The model results revealed poor water quality in the bay, indicating that immediate action was necessary to prevent further deterioration. The proposed staged reduction in discharges would initially have more severe effects than the current situation, but this would improve when the treatment plant became operational. However, even with the plant in operation, the complete sanitation of the bay cannot be achieved, and further measures are required. This study emphasizes the urgent need for effective and sustainable measures to improve water quality in Buenaventura Bay and demonstrates the usefulness of the modeling approach in identifying effective sanitation scenarios to achieve this goal. The results highlight the need for a comprehensive management strategy to tackle pollution in the bay and provide insights for other regions facing similar challenges.

Substance flow analysis of arsenic and its discharge reduction in the steelworks

Although certain emission standards have been implemented to reduce the air pollution from the steel industry, heavy metal pollution associated with steel production in China has not been well addressed yet. Arsenic is a metalloid element, commonly present in various compounds in many minerals. When it presents in steelworks, it not only affects the quality of steel products, but also causes environmental consequences such as soil degradation, water contamination, air pollution and associated biodiversity loss and public health risks. At present, most of the studies on arsenic were limited to its removal in a certain process, while there has not been a thorough analysis of the flow path of arsenic in steelworks that can facilitate a more efficient removal from its lifecycle. To achieve this, we established a model to depict arsenic flows in steelworks for the first time using adapted substance flow analysis. Then, we further analyzed arsenic flows in the steelworks using a case study in China. Finally, input-output analysis was applied to study the arsenic flow network and explore the reduction potential of arsenic-containing wastes in steelworks. The results show that: 1) the arsenic in the steelworks comes from inputs of iron ore concentrate (55.31 %), coal (12.71 %) and steel scrap (18.67 %), while the outputs were hot rolled coil (65.93 %) and slag (33.03 %). 2) The input, circulation, and final product content of arsenic are 96.120, 32.510, and 66.946 g/t-CS, respectively, and the recycling rate of arsenic was 48.28 %, in the steelworks. 3) The total arsenic discharge from the steelworks is 34.826 g/t-CS. 97.33 % of arsenic is discharged in the form of solid waste. 4) The reduction potential of arsenic in wastes is 14.31 % in the steelworks by adopting low-arsenic raw materials and removing arsenic from processes.

Enhancement of Partial Discharge Resistant Characteristics of XLPE Nanocomposites Using Plasma Treatment Technique

Polymer nanocomposites are well-known for their superior insulation properties over the existing polymer insulating material due to the existence of nanoparticles. However, the agglomeration of the nanoparticles within the polymer matrix is the main factor that restricts the enhancement of insulation characteristics because the nonuniform dispersion of nanoparticles reduces the interfacial area and creates weak polymer-nanofiller interfacial bonds. Thus, the main contribution of this work is conducting a comprehensive technique of nanoparticle surface modification using atmospheric pressure plasma (APP) to improve the surface compatibility between nanoparticles and polymer matrix, consequently enhancing insulation properties. In this study, the APP with the homogeneous and stable discharge was used in treating the surface of silicon dioxide (SiO2) nanoparticles to enhance its compatibility with cross-linked polyethylene (XLPE) matrices. In comparison with unfilled XLPE, the most effective formulation of XLPE nanocomposites was shown by the sample with 3 wt% of plasma-treated SiO2 nanoparticles with a reduction of partial discharge (PD) magnitude up to 62.85% and the reduction of PD numbers up to 26.70%. Plasma has proven to be a comprehensive technique to improve the PD resistance of XLPE nanocomposites by exciting the formation of more substantial interfacial regions through forming interfacial bonds and reducing the size and number of agglomerated clusters.

Secular trend in water discharge transport in the Lower Mekong River-delta: Effects of multiple anthropogenic stressors, rainfall, and tropical cyclones

The Mekong River is one of the world's most important continental rivers, and provides invaluable water resources for the survival and social development of nearly 70 million inhabitants of Southeast Asia. However, little work has been carried out on the multiforcing-induced hydrological behavior of the Lower Mekong River-delta (LMR) over the past 100 years. Here, the secular variations in water discharge were analyzed for seven gauging stations along the main stream of the LMR from the 1920s-2019, to identify the riverine hydrological mechanisms under different dynamic conditions. The results show that the water discharge delivered by the LMR to the delta decreased on both 50-year and centennial scales. Meanwhile, the daily water discharge of the LMR-delta has become more evenly distributed intra-annually, leading to “no flood in the flood season, no drought in the dry season” in this reach. While regional rainfall dominates the long-term variations in the water discharge in the LMR, episodic tropical cyclones can induce a gradual increase with enlarged spatial divergences in water discharge from the mountainous region to the delta by bringing heavy rainfall. Moreover, although the operation of the mega dams in the Upper Mekong Basin has significantly influenced the distribution of the downstream water discharge in the dry season, minor impacts can also be found in the wet season. The water consumption for irrigation was increased from the upstream to the downstream basin, which may contribute to the severe reduction in the downstream water discharge, even though typhoons induced much more runoff along the downstream reach. Considering future climate change in Southeast Asia with potential upward trends in anthropogenic stressors, it can be expected that the water discharge of the LMR-delta could worsen, and urgent countermeasures that address water resource management should be strongly considered by decision-makers in the affected countries of the Mekong River-delta.

Continuous Relationship of Operative Duration with Risk of Adverse Perioperative Outcomes and Early Discharge Undergoing Thoracoscopic Lung Cancer Surgery.

For thoracoscopic lung cancer surgery, the continuous relationship and the trigger point of operative duration with a risk of adverse perioperative outcomes (APOs) and early discharge remain unknown. This study enrolled 12,392 patients who underwent this surgical treatment. Five groups were stratified by operative duration: <60 min, 60-120 min, 120-180 min, 180-240 min, and ≥240 min. APOs included intraoperative hypoxemia, delayed extubation, postoperative pulmonary complications (PPCs), prolonged air leakage (PAL), postoperative atrial fibrillation (POAF), and transfusion. A restricted cubic spline (RCS) plot was used to characterize the continuous relationship of operative duration with the risk of APOs and early discharge. The risks of the aforementioned APOs increased with each additional hour after the first hour. A J-shaped association with APOs was observed, with a higher risk in those with prolonged operative duration compared with those with shorter values. However, the probability of early discharge decreased from 0.465 to 0.350, 0.217, and 0.227 for each additional hour of operative duration compared with counterparts (<60 min), showing an inverse J-shaped association. The 90 min procedure appears to be a tipping point for a sharp increase in APOs and a significant reduction in early discharge. Our findings have important and meaningful implications for risk predictions and clinical interventions, and early rehabilitation, for APOs.

Evaluating the impact of the COVID-19 pandemic on the delivery and efficiency of cardiac rehabilitation.

The SARS-CoV-2 (COVID-19) pandemic brought disruption to cardiac rehabilitation (CR) services in the UK, requiring innovation and use of remote interventions. This retrospective longitudinal study compares single-centre CR service data across three time periods: 'pre' (June 2019 to December 2019), 'during' (January 2020 to May 2020) and 'post' (June 2020 to December 2020), evaluating adaptations in programme delivery and subsequent effect on efficiency. There were 614 patients (72.7% male) identified between June 2019 and December 2020. Eligible CR referrals reduced 30.3% and encountered >50% decrease in engagement 'during' the pandemic, compared with 'pre' pandemic. The 'post' pandemic hybrid redesign led to a significant reduction in hospital discharge to CR contact (mean 5.39 days, p=0.001), and time spent in CR (41.33 days, p=0.001) when compared with 'pre' and 'during' figures. CR engagement significantly increased 'post' pandemic for ST-elevation myocardial infarction (STEMI)/non-STEMI (NSTEMI)/acute coronary syndrome (ACS) (56%, p=0.02) and 'post' cardiac surgery (76%, p=0.015). Referrals to cardiac psychology increased >50% 'post' pandemic (7.8%, p=0.038). A 'post' pandemic hybrid CR programme is effective at reducing wait times, increasing engagement and reducing time to completion of CR, compared with 'pre' and 'during' pandemic figures. A significant increase in cardiac psychology referrals 'post' pandemic highlights the importance of psychology support within CR.

The effect of channel geometry and check dam location on sediment transport discharge in the Kuranji River

Rivers as infrastructure carry water from upstream to downstream to meet the water needs of communities along the river and as drainage. Therefore, it is necessary to maintain the stability of the river from erosion and sedimentation. Changes in river geometry are mostly caused by the high intensity of rainfall in the upstream section. This causes the geometry to change easily, many bends are found, river embankments collapse, and the slope and flow of the river change suddenly. As a result, water will wash away sediment from upstream to downstream with high sediment discharge. However, the sediment rate/discharge can be reduced by building a check dam, but it needs the right location so that the construction of the check dam is effective and the river flow is stable. Research using HEC-RAS has been carried out at the location of the middle section of the Kuranji River, where simulating three check dam locations shows that the reduction in sediment discharge is very effective, but other places are still the same as without the check dam. Therefore, it is recommended to build check dam series and groundsills at narrowing locations and strengthen river banks at Sta. 16 to Sta. 32.

Hydrological and ecological impacts of run off river scheme; a case study of Ghazi Barotha hydropower project on Indus River, Pakistan

Run off river schemes are getting widespread importance as they are considered environmentally safe. However, number of studies and the consequent information regarding impacts of run off river schemes is very limited worldwide. Present study attempted to analyze impacts of Ghazi Barotha Hydropower Plant, which is a run off river scheme situated in Khyber Pakhtunkhwa province of Pakistan. This study attempted to analyze impacts of this run off river scheme on hydrological and ecological conditions of downstream areas. Data on river discharge, groundwater levels, agriculture area, vegetation and bare soil was utilized for this study. All data sets between the year 1990 till 2020 were analyzed. Hydrological impacts were analyzed through secondary data analysis, whereas ecological impacts were studied through remote sensing technique. Statistical methods were applied to further draw conclusions between hydrological and ecological interrelationships. Results showed that after functioning of Ghazi Barotha, there was 47% and 91% reduction of river discharge, in summer and winter seasons respectively. Groundwater level dropped by 50%. Agriculture area reduced by 1.69% and 9.11% during summer and winter respectively, whereas land under bare soil increased. River water diversion was considered to be responsible for groundwater reduction, as strong correlation was found between both. Agriculture land recovery, in post Ghazi Barotha period, was premised at intense groundwater mining, as groundwater level and agriculture area were significantly related (p < 0.05). Governments’ groundwater development schemes, and a shift into motorized groundwater mining were major factors behind further groundwater exploitation in study area. This study came to the conclusion that Ghazi Barotha Hydropower Plant had impacted flow regime of Indus River, as well as groundwater levels and land use of downstream area along the river. These effects were triggered by inappropriate compensatory measures and uncontrolled water resource exploitation.

Ottawa Risk Scale in Predicting the Outcome of Chorionic Obstructive Pulmonary Disease Exacerbation in Emergency Department; a Diagnostic Accuracy Study.

The disposition decision is a great challenge for clinicians in managing patients with chronic obstructive pulmonary disease (COPD) exacerbation. This study aimed to evaluate the accuracy of Ottawa COPD Risk Scale (OCRS) in predicting the short-term adverse events in the mentioned patients. This prospective diagnostic accuracy study was conducted on COPD exacerbation cases who were referred to the emergency department (ED). Patients were followed up for 30 consecutive days for adverse events including the need for intubation, non-invasive ventilation, myocardial infarction, readmission, and death from any cause, and finally the accuracy of OCRS in predicting the outcome was evaluated. 362 patients with the mean age of 65.55 ± 10.65 (6- 95) years were evaluated (58.0% male). Among the patients, 164 (45.3%) cases were discharged from ED, and 198 (54.7%) were admitted to the hospital. 136 (37.6%) cases experienced at least one of the studied short-term adverse events. The mean OCSD score of this series was 1.96 ± 2.39 (0 - 10). The area under the curve of OCRS in predicting the outcome of COPD patients was 0.814 (95%CI: 0.766 - 0.862). The best cut-off point of the scale in predicting the outcome was 1.5. The sensitivity and specificity of the scale were 75.75% (95%CI: 69.6% - 81.42%) and 89.63% (95%CI: 83.67% - 93.66%), respectively. By employing this threshold, 48 (13.25%) cases would have unnecessary hospitalization, and 17 (0.04%) would be discharged incorrectly. The OCRS has acceptable level of prediction accuracy in predicting the short-term adverse event of COPD patients. The use of this scoring in the routine practice of ED clinicians can lead to a reduction in unnecessary admissions and unsafe discharge for these patients.

Management of bronchopleural fistula using Amplatzer duct occluder device.

Management of bronchopleural fistula using Amplatzer duct occluder device.