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1.
J Environ Manage ; 352: 120054, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38211432

RESUMEN

Adoption of edge-of-field conservation practices, such as denitrifying bioreactors, may be intrinsically linked to barriers associated with cost. However, most previous bioreactor cost efficiency assessments assumed values for either costs and/or nitrate removal. The objective of this work was to use actual construction costs as well as monitored nitrate removal to develop empirical cost efficiencies for eight full-size bioreactors in Illinois, USA. Capital construction costs were obtained via invoices or personal communications. A cash-flow discounting procedure was used to develop an equal annualized cost for each bioreactor assuming two media recharges over a 24-y planning horizon. These costs were combined with monitored nitrate removal based on one to six years of monitoring per site. Construction costs averaged $12,250 ± $7520 across the eight sites (or, $16,020 ± $9960 in 2023 price levels) but considering one of the sites was a paired bioreactor system, costs averaged $10,890 per bioreactor unit. Drainage treatment area-based cost averaged $132/ha-y and treatment area was strongly correlated with capital costs (R2 = 0.90; p = 0.001). The bioreactors averaged $108/m3 of woodchips and available federal government conservation programs could have offset an average of 70% of this cost. Monitored nitrate removal across 27 site-years resulted in a median of $33/kg N-y removed. This mass-based cost efficiency was higher than most previous assessments because the monitored nitrate removal for the study sites was lower than has been previously assumed or modeled. Future reporting about bioreactor recharge timing and cost will help guide assessment and planning. Water quality planning efforts should also consider the increasingly important engineering design costs, which were not included here. Suggested research and outreach to improve bioreactor cost efficiencies involves scaling the physical capacity of this technology for larger treatment areas, revisiting the use of low-cost non-standard fill media, and providing practical construction training.


Asunto(s)
Desnitrificación , Nitratos , Reactores Biológicos , Illinois
2.
Front Bioeng Biotechnol ; 11: 1242927, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38076437

RESUMEN

Anaerobic membrane bioreactors (AnMBR) have been used for treating high-strength industrial wastewater at full-scale and the potential to use them for mainstream municipal wastewater treatment presents an important opportunity to turn energy-intensive plants into net-energy producers. However, several limitations of the AnMBR technology have prevented their adoption in the municipal wastewater industry, namely, high membrane cleaning energy demand and low membrane flux. This study demonstrated a novel AnMBR configuration that uses a commercially available cloth filter technology to address the key limitations of cleaning energy and membrane flux. The cloth filter anaerobic membrane bioreactor (CFAnMBR) is comprised of an anaerobic fixed-film bioreactor coupled with a cloth filter membrane with nominal pore size of 5 µm. The pilot CFAnMBR was operated for 150 days through the winter at a municipal wastewater plant in central Illinois (minimum/average influent temperature 5/13°C). The CFAnMBR increased membrane flux by more than 2 orders of magnitude (3,649 ± 1,246 L per meter squared per hour) and reduced cleaning energy demand by 78%-92% (0.0085 kWh/m3) relative to previously reported AnMBR configurations. With the CFAnMBR, average chemical oxygen demand and total suspended solids removal were 66% and 91%, respectively, and were shown to be increased up to 88% and 96% by in-line coagulant dosing with ferric chloride. Average headspace methane yield was 154 mL CH4/g CODremoved by the end of the study period with influent temperatures of 11°C± 4°C. The CFAnMBR resolves major limitations of AnMBR technology by employing a commercially-available technology already used for other municipal wastewater treatment applications.

3.
J Inj Violence Res ; 15(2): 129-136, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37393520

RESUMEN

BACKGROUND: SARS-CoV-2 positive status has been considered a predominantly incidental finding among trauma patients. We sought to examine whether concurrent infection is associated with worse outcomes in a contemporary cohort of injured patients during the COVID-19 pandemic. METHODS: Retrospective cohort analysis of a level I trauma center's institutional registry from May 1, 2020 through June 30, 2021. The prevalence of COVID in the trauma population was compared monthly using prevalence ratios relative to population estimates. Unadjusted cohorts of COVID+ vs COVID- trauma patients were compared. COVID+ patients then were matched on age, mechanism of injury, year, and injury severity score (ISS) with COVID- controls for adjusted analysis with a primary composite outcome of mortality. RESULTS: Out of n=2,783 trauma activations, n=51 (1.8%) were COVID+. Compared to the general population, the trauma population had prevalence ratios for COVID of 5.3 to 79.7 (median=20.8). Compared to COVID- patients, COVID+ patients had worse outcomes, including a higher proportion who were admitted to the ICU, required intubation, underwent a major operation, and had greater total charges and a longer length of stay. However, these differences appeared related to more severe injury patterns in the COVID+ cohort. In the adjusted analysis, no significant differences between groups in any of the outcome variables were observed. CONCLUSIONS: Worse trauma outcomes in COVID+ patients appear to be correlated to the more substantial patterns of injury observed in this group. Trauma patients have substantially higher rates of SARS-CoV-2 positivity than the local population at large. These results reinforce that this population is vulnerable to multiple threats. They will guide the ongoing delivery of care in shaping the needs for testing, PPE for those delivering care, and the capacity and operational needs of trauma systems that must care for a population with such high rates of SARS-CoV-2 infection.


Asunto(s)
COVID-19 , Servicios Médicos de Urgencia , Humanos , Estudios Retrospectivos , Pandemias , Estudios de Cohortes , Centros Traumatológicos
4.
J Environ Manage ; 319: 115768, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35982568

RESUMEN

Denitrifying bioreactors are a conservation drainage practice for reducing nitrate loads in subsurface agricultural drainage. Bioreactor hydraulic capacity is limited by cross-sectional area perpendicular to flow through the woodchip bed, with excess bypass flow untreated. Paired bioreactors with wide orientations were built in 2017 in Illinois, USA, to treat drainage from a relatively large 29 ha field. The paired design consisted of: a larger, Main bioreactor (LWD: 6.1 × 18.3 × 0.9 m) for treating base flow, and 2) a smaller, Booster bioreactor (7.8 × 13.1 × 0.9 m) receiving bypass flow from the Main bioreactor during periods of high flow. Over three years of monitoring, the paired bioreactor captured 84-92% of the annual drainage discharge which demonstrated an expanded cross-sectional area could improve bioreactor flow capture, even for a large drainage area. However, the paired bioreactors removed 6-28% of the annual N load leaving the field (1.8-5.6 kg N ha-1 removed; 52-161 kg N), which was not a notable improvement compared to bioreactors treating smaller drainage areas. The design operated as intended at low annual flow-weighted hydraulic retention times (HRTs) of usually ≤2 h, but these short HRTs ultimately limited bioreactor nitrate removal efficiency. Daily HRTs of <2 h often resulted in nitrate flushing. The Main bioreactor had higher hydraulic loading as intended and was responsible for the majority of flow captured in each year although not always the most nitrate mass removal. The Booster bioreactor provided better nitrate removal than the Main at HRTs of 3.0-11.9 h, possibly due to its drying cycles which may have liberated more available carbon. This new design approach tested at the field-scale illustrated tradeoffs between greater flow capacity (via increased bioreactor width) and longer HRT (via increased length), given a consistent bioreactor surface footprint.


Asunto(s)
Desnitrificación , Nitratos , Agricultura , Reactores Biológicos , Óxidos de Nitrógeno
6.
J Environ Manage ; 289: 112521, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33839611

RESUMEN

Woodchip bioreactors are widely known as a best management practice to reduce excess nitrate loads that are discharged with agricultural leachates. The aim of this study was to evaluate the performance of citrus woodchip bioreactors for denitrification of brine (electrical conductivity ≈ 17 mS cm-1) from groundwater desalination plants with high nitrate content (NO3--N ≈ 48 mg L-1) in the Campo de Cartagena agricultural watershed, one of the main providers of horticultural products in Europe. The performance was evaluated relative to seasonal changes in temperature, dissolved organic carbon (DOC) provided by woodchips, hydraulic residence time (HRT) and woodchip aging. Bioreactors (capacity 1 m3) operated for 2.5 years (121 weeks) in batch mode (24 h HRT) with three batches per week. Denitrification efficiency was modulated by DOC concentration, temperature, hydraulic residence time and the drying-rewetting cycles. High salinity of brine did not prevent nitrate removal from occurring. The high DOC availability (>25 mg C L-1) during the first ≈48 weeks resulted in high nitrate removal rate (>75%) and nitrate removal efficiency (until ≈ 25 g N m-3 d-1) regardless of temperature. Moreover, the high DOC contents in the effluents during this period may present environmental drawbacks. Denitrification was still high after 2.5 years (reaching ≈9.3 g N m-3 d-1 in week 121), but dependence on warm temperature became more apparent with woodchips aging from week ≈49 onwards. Nitrate removal efficiency was highest on the first weekly batch, immediately after woodchips had been unsaturated for four days. It was attributable to a flush of DOC produced by aerobic microbial metabolism during drying that stimulated denitrification following re-saturation. Hence, alternance of drying-rewetting cycles is an operation practice that increase bioreactors nitrate removal performance.


Asunto(s)
Desnitrificación , Agua Subterránea , Reactores Biológicos , Europa (Continente) , Nitratos , Sales (Química)
7.
Acute Med Surg ; 8(1): e636, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33747534

RESUMEN

AIM: Gunshot wounds (GSW) to the penis represent a rare type of traumatic injury in the civilian United States population. Although small, single-center studies have reported results of care for these types of injured patients, no national analyses have examined this group. METHODS: A cohort of patients with GSW to the penis was identified using the 2017 American College of Surgeons Trauma Quality Programs database, a comprehensive national database of 753 accredited trauma centers. RESULTS: Gunshot wounds to the penis occurred in 722 patients, which represents 1.7% of all GSW patients (n = 41,017). Gunshot wounds from altercations with law enforcement or accidental discharge of a firearm were rare; the vast majority (n = 655, 90.7%) occurred as a result of assault, intentional self-harm, attempted suicide, or attempted homicide. Patients with a major concomitant non-genitourinary injury comprised 119 (16.5%) patients of the cohort. Most patients (n = 499, 69.1%) underwent a genitourinary procedure during their trauma admission. Penile salvage was successful in most cases, with only 13 (1.8%) patients requiring completion penectomy. Most patients (87.8%) required admission with a median length of stay of 49.8 h. Most patients were treated at the initial trauma center without requiring transfer to another center, and complications during admission were rare. CONCLUSIONS: This analysis, the first national examination of care of patients with GSW to the penis, reveals overall favorable outcomes. Admission and surgical intervention were required in most patients, but penectomy was rare and length of stay was generally short. These results will guide resource utilization and quality improvement efforts in this patient cohort.

8.
Pediatr Res ; 89(4): 767-769, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32947605

RESUMEN

BACKGROUND: National guidelines recommend screening all trauma patients for drug and alcohol use beginning at age 12, but no national data have examined rates of screening or positive results in this population. METHODS: We examined national testing rates and results among all trauma patients under 21 years old in the 2017 American College of Surgeons Trauma Quality Programs (TQP) database. RESULTS: Of a cohort of n = 157,450 pediatric and adolescent trauma patients, n = 45,443 (28.9%) were screened, and n = 16,662 (36.7%) of those had a positive result. While both testing and positive results increased with age, testing rates were only 61.7% by age 20 and the prevalence of positive results was significant even at younger ages. Cannabinoids were the most commonly detected substance, followed by alcohol, and then opioids. CONCLUSIONS: These national data support the need for further efforts to increase screening rates and provide structured interventions to mitigate the consequences of substance abuse. IMPACT: These data provide the first national evidence of underutilization of drug and alcohol screening in pediatric and adolescent trauma patients, with substantial rates of positive screens among those tested. Cannabinoids were the most commonly detected substance, followed by alcohol and then opioids. These data should guide physicians' and policymakers' efforts to improve screening in this high-risk population, which will amplify the potential benefits of using the trauma admission as a critical opportunity to intervene with structured programs to mitigate the consequences of substance abuse.


Asunto(s)
Consumo de Bebidas Alcohólicas , Analgésicos Opioides/análisis , Cannabinoides/análisis , Etanol/análisis , Tamizaje Masivo/métodos , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiología , Adolescente , Niño , Estudios de Cohortes , Bases de Datos Factuales , Servicio de Urgencia en Hospital , Femenino , Humanos , Masculino , Estados Unidos , Heridas y Lesiones/terapia , Adulto Joven
9.
J Environ Manage ; 272: 110996, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32854899

RESUMEN

Woodchip bioreactors are a practical, low-cost technology for reducing nitrate (NO3) loads discharged from agriculture. Traditional methods of quantifying their performance in the field mostly rely on low-frequency, time-based (weekly to monthly sampling interval) or flow-weighted sample collection at the inlet and outlet, creating uncertainty in their performance and design by providing incomplete information on flow and water chemistry. To address this uncertainty, two field bioreactors were monitored in the US and New Zealand using high-frequency, multipoint sampling for in situ monitoring of NO3-N concentrations. High-frequency monitoring (sub hourly interval) at the inlet and outlet of both bioreactors revealed significant variability in volumetric removal rates and percent reduction, with percent reduction varying by up to 25 percentage points within a single flow event. Time series of inlet and outlet NO3 showed significant lag in peak concentrations of 1-3 days due to high hydraulic residence time, where calculations from instantaneous measurements produced erroneous estimates of performance and misleading relationships between residence time and removal. Internal porewater sampling wells showed differences in NO3 concentration between shallow and deep zones, and "hot spot" zones where peak NO3 removal co-occurred with dissolved oxygen depletion and dissolved organic carbon production. Tracking NO3 movement through the profile showed preferential flow occurring with slower flow in deeper woodchips, and slower flow further from the most direct flowpath from inlet to outlet. High-frequency, in situ data on inlet and outlet time series and internal porewater solute profiles of this initial work highlight several key areas for future research.


Asunto(s)
Reactores Biológicos , Desnitrificación , Nueva Zelanda , Nitratos/análisis , Sesgo de Selección
10.
Womens Health (Lond) ; 16: 1745506520933021, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32578516

RESUMEN

BACKGROUND: Pregnancy has been identified as a risk factor for poor outcomes after traumatic injury, but prior outcome analyses are conflicting and dated. We sought to examine outcomes in a contemporary cohort. METHODS: Retrospective cohort analysis at a level I trauma center's institutional registry from 2009 to 2018, with comparison to population-level demographic trends in women of reproductive age and pregnancy prevalence. Unadjusted cohorts of pregnant versus nonpregnant trauma patients were compared. Pregnant patients then were matched on age, mechanism of injury, year, and injury severity score with nonpregnant controls for adjusted analysis with a primary outcome of maternal mortality. RESULTS: Despite declining birth and pregnancy rates in the population, pregnant women comprised a stable 5.3% of female trauma patients of reproductive age without decline over the study period (p = 0.53). Compared with nonpregnant women, pregnant trauma patients had a lower injury severity score (1 [1-5] vs 5 [1-10] p < 0.0001) and a shorter length of stay (1 [1-2] vs 1 [1-4] p = 0.04), were less likely to have CT imaging (48.8% vs 67.4%, p < 0.0001) and more likely to be admitted (89.3% vs 79.2%, p = 0.003). Positive toxicology screens were less prevalent in pregnant women, but only for ethanol (5.4% vs 31.4%, p < 0.0001); there was no difference in rates of cannabis, opiates, or cocaine. After matching to adjust for age, year, mechanism of injury, and injury severity score, mortality occurred significantly more frequently in the pregnant cohort (2.1% vs 0.2%, OR = 13.5 [1.39-130.9], p = 0.02). CONCLUSION: Pregnant trauma patients have not declined in our population despite population-level declines in pregnancy. After adjusting for lower injury severity, pregnant women were at substantially greater risk of mortality. This supports ongoing concern for pregnant trauma patients as a vulnerable population. Further efforts should optimize systems of care to maximize the chances of rescue for both mother and fetus.


Asunto(s)
Complicaciones del Embarazo/mortalidad , Centros Traumatológicos/estadística & datos numéricos , Heridas y Lesiones/mortalidad , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Mortalidad Materna , Oregon/epidemiología , Embarazo , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
11.
Ann Card Anaesth ; 23(1): 70-74, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31929251

RESUMEN

Background/Aims: Methadone may offer advantages in facilitating early extubation after cardiac surgery, but very few data are available in the pediatric population. Setting/Design: Community tertiary children's hospital, retrospective case series. Materials and Methods: We performed a retrospective analysis of all pediatric cardiac surgical patients for whom early extubation was intended. A multimodal analgesic regimen was used for all patients, consisting of methadone (0.2-0.3 mg/kg), ketamine (0.5 mg/kg plus 0.25 mg/kg/h), lidocaine (1 mg/kg plus 1.5 mg/kg/h), acetaminophen (15 mg/kg), and parasternal ropivacaine (0.5 mL/kg of 0.2%). Outcome variables were collected with descriptive statistics. Results: A total of 24 children [median = 7 (interquartile range = 3.75-13.75) years old, 23.7 (14.8-53.4) kg] were included in the study; 22 (92%) had procedures performed on bypass and 11 (46%) involved a reentry sternotomy. Methadone dosing was 0.26 (0.23-0.29) mg/kg. None of the children required intraoperative supplemental opioids; 23 (96%) were extubated in the operating room. The first paCO2 on pediatric intensive care unit admission was 51 (45-58) mmHg. Time to first supplemental opioid administration was 5.1 (3.5-9.5) h. Cumulative total supplemental opioids (in intravenous morphine equivalents) at 24 and 72 h were 0.2 (0.09-0.32) and 0.42 (0.27-0.68) mg/kg. One child required postoperative bilevel positive airway pressure support, but none required reintubation. None had pruritus; three (13%) experienced nausea. Conclusion: A methadone-based multimodal regimen facilitated early extubation without appreciable adverse events. Further investigations are needed to confirm efficacy of this regimen and to assess whether the excellent safety profile seen here holds in the hands of multiple providers caring for a larger, more heterogeneous population.


Asunto(s)
Extubación Traqueal/estadística & datos numéricos , Analgésicos Opioides/uso terapéutico , Cardiopatías Congénitas/cirugía , Tiempo de Internación/estadística & datos numéricos , Metadona/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Adolescente , Extubación Traqueal/métodos , Procedimientos Quirúrgicos Cardíacos , Niño , Preescolar , Humanos , Masculino , Estudios Retrospectivos , Factores de Tiempo
12.
J Trauma Acute Care Surg ; 88(1): 134-140, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31688790

RESUMEN

BACKGROUND: Trauma-induced coagulopathy seen on rotational thromboelastometry (ROTEM) is associated with poor outcomes in adults; however, this relationship is poorly understood in the pediatric population. We sought to define thresholds for product-specific transfusion and evaluate the prognostic efficacy of ROTEM in injured children. METHODS: Demographics, ROTEM, and clinical outcomes from severely injured children (age, < 18 years) admitted to a Level I trauma center between 2014 and 2018 were retrospectively analyzed. Receiver operating characteristic curves were plotted and Youden indexes were calculated against the endpoint of packed red blood cell transfusion to identify thresholds for intervention. The ROTEM parameters were compared against the clinical outcomes of mortality or disability at discharge. RESULTS: Ninety subjects were reviewed. Increased tissue factor-triggered extrinsic pathway (EXTEM) clotting time (CT) >84.5 sec (p = 0.049), decreased EXTEM amplitude at 10 minutes (A10) <43.5 mm (p = 0.025), and decreased EXTEM maximal clot firmness (MCF) <64.5 mm (p = 0.026) were associated with need for blood product transfusion. Additionally, EXTEM CT longer than 68.5 seconds was associated with mortality or disability at discharge. CONCLUSION: Coagulation dysregulation on thromboelastometry is associated with disability and mortality in children. Based on our findings, we propose ROTEM thresholds: plasma transfusion for EXTEM CT longer than 84.5 seconds, fibrinogen replacement for EXTEM A10 less than 43.5 mm, and platelet transfusion for EXTEM MCF less than 64.5 mm. LEVEL OF EVIDENCE: Prognostic, Level III; Therapeutic, Level IV.


Asunto(s)
Trastornos de la Coagulación Sanguínea/diagnóstico , Transfusión de Componentes Sanguíneos/normas , Tromboelastografía/métodos , Heridas y Lesiones/complicaciones , Adolescente , Trastornos de la Coagulación Sanguínea/etiología , Trastornos de la Coagulación Sanguínea/mortalidad , Trastornos de la Coagulación Sanguínea/terapia , Transfusión de Componentes Sanguíneos/métodos , Transfusión de Componentes Sanguíneos/estadística & datos numéricos , Niño , Toma de Decisiones Clínicas , Femenino , Mortalidad Hospitalaria , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Guías de Práctica Clínica como Asunto , Valor Predictivo de las Pruebas , Pronóstico , Curva ROC , Estudios Retrospectivos , Centros Traumatológicos/estadística & datos numéricos , Resultado del Tratamiento , Heridas y Lesiones/diagnóstico , Heridas y Lesiones/mortalidad , Heridas y Lesiones/terapia
14.
J Hosp Med ; 15(8): 468-474, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31869291

RESUMEN

BACKGROUND: Medical comanagement entails a significant commitment of clinical resources with the aim of improving perioperative outcomes for patients admitted with hip fractures. To our knowledge, no national analyses have demonstrated whether patients benefit from this practice. METHODS: We performed a retrospective cohort analysis of the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) targeted user file for hip fracture 2016-2017. Medical comanagement is a dedicated variable in the NSQIP. Propensity score matching was performed to control for baseline differences associated with comanagement. Matched pairs binary logistic regression was then performed to determine the effect of comanagement on the following primary outcomes: mortality and a composite endpoint of major morbidity. RESULTS: Unadjusted analyses demonstrated that patients receiving medical comanagement were older and sicker with a greater burden of comorbidities. Comanagement did not have a higher proportion of patients participating in a standardized hip fracture program (53.6% vs 53.7%; P > .05). Comanagement was associated with a higher unadjusted rate of mortality (6.9% vs 4.0%, odds ratio [OR] 1.79: 1.44-2.22; P < .0001) and morbidity (19.5% vs 9.6%, OR 2.28: 1.98-2.63; P < .0001). After propensity score matching was used to control for baseline differences associated with comanagement, patients in the comanagement cohort continued to demonstrate inferior mortality (OR 1.36: 1.02-1.81; P = .033) and morbidity (OR 1.82: 1.52-2.20; P < .0001). CONCLUSIONS: This analysis does not provide evidence that dedicated medical comanagement of hip fracture patients is associated with superior perioperative outcomes. Further efforts may be needed to refine opportunities to modify the significant morbidity and mortality that persists in this population.


Asunto(s)
Fracturas de Cadera , Mejoramiento de la Calidad , Estudios de Cohortes , Fracturas de Cadera/cirugía , Humanos , Complicaciones Posoperatorias , Puntaje de Propensión , Estudios Retrospectivos , Resultado del Tratamiento
15.
Sci Total Environ ; 718: 135267, 2020 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-31859060

RESUMEN

The increase in environmental nutrient availability as a result of human activities has necessitated the development of mitigation strategies for nutrient removal, such as nitrate. Current methods for determining the efficiency of different mitigation strategies required measurement of changes in nitrate concentrations, however, these methods can be expensive or do not account fully for the temporal variability of nitrate concentration. This study evaluated the utility of Diffusive Gradients in Thins-Films (DGT) for determining nitrate removal in two denitrifying bioreactors, and compared DGT performance to traditional approaches for determining performance, including high and low frequency water grab sampling. The binding layer was produced using the Purolite® A520E anion exchange resin. The uptake and elution efficiencies were 98.8% and 93.4% respectively. DGTs of three material diffusion layer thicknesses were placed in piezometers along longitudinal transects, to enable calculation of the diffusive boundary layer and provide replicates. These were removed after 16, 24 and 36 h, and the accumulated nitrate masses were extracted and quantified to calculate nitrate concentration. Concentrations were subsequently utilised to calculate nitrate removal rates in both bioreactors. Grab samples were taken at 30 and 60 min intervals over those periods, nitrate concentrations were also measured to determine nitrate removal. DGTs provided nitrate removal rates at bioreactor site one (controlled flow, wastewater treatment) of 14.83-30.75 g N m-3 d-1, and 1.22-3.63 g N m-3 d-1 at site two (variable flow, agricultural run-off). DGT determined nitrate concentrations and removal rates were in strong accordance with high frequency grab sampling, but data collection via DGTs was considerably easier. Utilising DGTs for the measurement of bioreactor performance overcame many of the challenges associated with high frequency grab sampling, and other methods, such as accounting for temporal variation in nitrate concentration and reduced analytical requirements.


Asunto(s)
Reactores Biológicos , Difusión , Monitoreo del Ambiente , Nitratos , Aguas Residuales
16.
J Environ Qual ; 48(1): 93-101, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30640347

RESUMEN

Woodchip bioreactors are widely used to control nitrogen export from agriculture using denitrification. There is abundant evidence that drying-rewetting (DRW) cycles can promote enhanced metabolic rates in soils. A 287-d experiment investigated the effects of weekly DRW cycles on nitrate (NO) removal in woodchip columns in the laboratory receiving constant flow of nitrated water. Columns were exposed to continuous saturation (SAT) or to weekly, 8-h drying-rewetting (8 h of aerobiosis followed by saturation) cycles (DRW). Nitrate concentrations were measured at the column outlets every 2 h using novel multiplexed sampling methods coupled to spectrophotometric analysis. Drying-rewetting columns showed greater export of total and dissolved organic carbon and increased NO removal rates. Nitrate removal rates in DRW columns increased by up to 80%, relative to SAT columns, although DRW removal rates decreased quickly within 3 d after rewetting. Increased NO removal in DRW columns continued even after 39 DRW cycles, with ∼33% higher total NO mass removed over each weekly DRW cycle. Data collected in this experiment provide strong evidence that DRW cycles can dramatically improve NO removal in woodchip bioreactors, with carbon availability being a likely driver of improved efficiency. These results have implications for hydraulic management of woodchip bioreactors and other denitrification practices.


Asunto(s)
Desnitrificación , Nitratos , Reactores Biológicos , Carbono , Nitrógeno
17.
J Am Heart Assoc ; 7(15): e008775, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30371225

RESUMEN

Background This study assessed trends in heart failure ( HF) hospitalizations and health resource use in patients with adult congenital heart disease ( ACHD ). Methods and Results The Nationwide Inpatient Sample was used to compare ACHD with non- ACHD HF hospitalization and health resource trends. Health resource use was assessed using total hospital charges, hospital length of stay, and procedural burden. A total of 87 175±2676 ACHD -related HF hospitalizations occurred between 1998 and 2011. During this time, ACHD HF hospitalizations increased 91% (4620±438-8809±740, P<0.0001) versus a 21% increase in non- ACHD HF hospitalizations ( P=0.003). ACHD HF hospitalization was associated with longer length of stay ( ACHD HF versus non- ACHD HF, 7.2±0.09 versus 6.8±0.02 days; P<0.0001), greater procedural burden, and higher charges ($81 332±$1650 versus $52 050±$379; P<0.0001). ACHD HF hospitalization charges increased 258% during the study period ($26 533±$1816 in 1998 versus $94 887±$8310 in 2011; P=0.0002), more than double that for non- ACHD HF ( P=0.04). Patients with ACHD HF hospitalized in high-volume ACHD centers versus others were more likely to undergo invasive hemodynamic testing (30.2±0.6% versus 20.7±0.5%; P<0.0001) and to receive cardiac resynchronization/defibrillator devices (4.7±0.3% versus 1.8±0.2%; P<0.0001) and mechanical circulatory support (3.9±0.2% versus 2.4±0.2%; P<0.0001). Conclusions ACHD -related HF hospitalizations have increased dramatically in recent years and are associated with disproportionately higher costs, procedural burden, and health resource use.


Asunto(s)
Servicios de Salud/tendencias , Cardiopatías Congénitas/terapia , Insuficiencia Cardíaca/terapia , Hospitalización/tendencias , Adolescente , Adulto , Anciano , Dispositivos de Terapia de Resincronización Cardíaca/tendencias , Desfibriladores Implantables/tendencias , Anomalía de Ebstein , Femenino , Recursos en Salud/tendencias , Cardiopatías Congénitas/complicaciones , Cardiopatías Congénitas/etiología , Insuficiencia Cardíaca/economía , Insuficiencia Cardíaca/etiología , Defectos de los Tabiques Cardíacos , Precios de Hospital/tendencias , Humanos , Tiempo de Internación/tendencias , Masculino , Persona de Mediana Edad , Tetralogía de Fallot , Transposición de los Grandes Vasos , Estados Unidos , Adulto Joven
18.
Cureus ; 10(1): e2072, 2018 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-29552434

RESUMEN

Morbidity and mortality risk increase considerably for patients with pulmonary hypertension (PH) undergoing non-cardiac surgery. Unfortunately, there are no comprehensive, evidence-based guidelines for perioperative evaluation and management of these patients. We present a brief review of the literature on perioperative outcomes for patients with PH and describe the implementation of a collaborative perioperative management program for these high-risk patients at a tertiary academic center.

19.
J Trauma Acute Care Surg ; 85(4): 659-664, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29554039

RESUMEN

BACKGROUND: Expediting evaluation and intervention for severely injured patients has remained a mainstay of advanced trauma care. One technique, direct to operating room (DOR) resuscitation, for selective adult patients has demonstrated decreased mortality. We sought to investigate the application of this protocol in children. METHODS: All DOR pediatric patients from 2009 to 2016 at a pediatric Level I trauma center were identified. Direct to OR criteria included penetrating injury, chest injuries, amputations, significant blood loss, cardiopulmonary resuscitation, and surgeon discretion. Demographics, injury patterns, interventions, and outcomes were analyzed. Observed mortality was compared with expected mortality, calculated using Trauma Injury Severity Score methodology, with two-tailed t tests, and a p value less than 0.5 was considered significant. RESULTS: Of 2,956 total pediatric trauma activations, 82 (2.8%) patients (age range, 1 month to 17 years) received DOR resuscitation during the study period. The most common indications for DOR were penetrating injuries (62%) and chest injuries (32%). Forty-four percent had Injury Severity Score (ISS) greater than 15, 33% had Glasgow Coma Scale (GCS) score of 8 or less, and 9% were hypotensive. The most commonly injured body regions were external (66%), head (34%), chest (30%), and abdomen (27%). Sixty-seven (82%) patients required emergent procedural intervention, most commonly wound exploration/repair (35%), central venous access (22%), tube thoracostomy (19%), and laparotomy (18%). Predictors of intervention were ISS greater than 15 (odds ratio, 14; p = 0.013) and GCS < 9 (odds ratio = 8.5, p = 0.044). The survival rate to discharge for DOR patients was 84% compared with an expected survival of 79% (Trauma Injury Severity Score) (p = 0.4). The greatest improvement relative to expected mortality was seen in the subgroup with penetrating trauma (84.5% vs 74.4%; p = 0.002). CONCLUSION: A selective policy of resuscitating the most severely injured children in the OR can decrease mortality. Patients suffering penetrating trauma with the highest ISS, and diminished GCS scores have the greatest benefit. Trauma centers with appropriate resources should evaluate implementing similar policies. LEVEL OF EVIDENCE: Diagnostic tests or criteria, level II.


Asunto(s)
Resucitación/métodos , Heridas y Lesiones/mortalidad , Heridas y Lesiones/cirugía , Traumatismos Abdominales/mortalidad , Traumatismos Abdominales/cirugía , Adolescente , Cateterismo Venoso Central , Niño , Preescolar , Protocolos Clínicos , Traumatismos Craneocerebrales/mortalidad , Traumatismos Craneocerebrales/cirugía , Técnicas de Diagnóstico Quirúrgico , Tratamiento de Urgencia , Femenino , Escala de Coma de Glasgow , Humanos , Hipotensión/etiología , Lactante , Puntaje de Gravedad del Traumatismo , Masculino , Quirófanos , Tasa de Supervivencia , Traumatismos Torácicos/mortalidad , Traumatismos Torácicos/cirugía , Toracostomía , Triaje , Heridas y Lesiones/complicaciones , Heridas Penetrantes/mortalidad , Heridas Penetrantes/cirugía
20.
J Heart Lung Transplant ; 37(1): 89-99, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28365175

RESUMEN

BACKGROUND: Adults with congenital heart disease represent an expanding and unique population of patients with heart failure (HF) in whom the use of mechanical circulatory support (MCS) has not been characterized. We sought to describe overall use, patient characteristics, and outcomes of MCS in adult congenital heart disease (ACHD). METHODS: All patients entered into the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) between June 23, 2006, and December 31, 2015, were included. Patients with ACHD were identified using pre-operative data and stratified by ventricular morphology. Mortality was compared between ACHD and non-ACHD patients, and multivariate analysis was performed to identify predictors of death after device implantation. RESULTS: Of 16,182 patients, 126 with ACHD stratified as follows: systemic morphologic left ventricle (n = 63), systemic morphologic right ventricle (n = 45), and single ventricle (n = 17). ACHD patients were younger (42 years ± 14 vs 56 years ± 13; p < 0.0001) and were more likely to undergo device implantation as bridge to transplant (45% vs 29%; p < 0.0001). A higher proportion of ACHD patients had biventricular assist device (BiVAD)/total artificial heart (TAH) support compared with non-ACHD patients (21% vs 7%; p < 0.0001). More ACHD patients on BiVAD/TAH support were INTERMACS profile 1 compared with patients on systemic left ventricular assist device (LVAD) support (35% vs 15%; p = 0.002). ACHD and non-ACHD patients with LVADs had similar survival; survival was worse for patients on BIVAD/TAH support. BiVAD/TAH support was the only variable independently associated with mortality (early phase hazard ratio 4.4; 95% confidence interval, 1.8-11.1; p = 0.001). For ACHD patients receiving MCS, ventricular morphology was not associated with mortality. CONCLUSIONS: ACHD patients with LVADs have survival similar to non-ACHD patients. Mortality is higher for patients requiring BiVAD/TAH support, potentially owing to higher INTERMACS profile. These outcomes suggest a promising role for LVAD support in ACHD patients as part of the armamentarium of therapies for advanced HF.


Asunto(s)
Cardiopatías Congénitas/complicaciones , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/cirugía , Corazón Artificial , Corazón Auxiliar , Adulto , Bases de Datos Factuales , Femenino , Insuficiencia Cardíaca/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Tasa de Supervivencia , Resultado del Tratamiento , Estados Unidos
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