Acute severe paediatric asthma: Study protocol for the development of a core outcome set, a Pediatric Emergency Research Networks (PERN) study

BackgroundAcute severe childhood asthma is an infrequent, but potentially life-threatening emergency condition. There is a wide range of different approaches to this condition, with very little supporting evidence, leading to significant variation in practice. To improve knowledge in this area, there must first be consensus on how to conduct clinical trials, so that valid comparisons can be made between future studies. We have formed an international working group comprising paediatricians and emergency physicians from North America, Europe, Asia, the Middle East, Africa, South America, Central America, Australasia and the United Kingdom.Methods/designA 5-stage approach will be used: (1) a comprehensive list of outcomes relevant to stakeholders will be compiled through systematic reviews and qualitative interviews with patients, families, and clinicians; (2) Delphi methodology will be applied to reduce the comprehensive list to a core outcome set; (3) we will review current clinical practice guidelines, existing clinical trials, and literature on bedside assessment of asthma severity. We will then identify practice differences in tne clinical assessment of asthma severity, and determine whether further prospective work is needed to achieve agreement on inclusion criteria for clinical trials in acute paediatric asthma in the emergency department (ED) setting; (4) a retrospective chart review in Australia and New Zealand will identify the incidence of serious clinical complications such as intubation, ICU admission, and death in children hospitalized with acute severe asthma. Understanding the incidence of such outcomes will allow us to understand how common (and therefore how feasible) particular outcomes are in asthma in the ED setting; and finally (5) a meeting of the Pediatric Emergency Research Networks (PERN) asthma working group will be held, with invitation of other clinicians interested in acute asthma research, and patients/families. The group will be asked to achieve consensus on a core set of outcomes and to make recommendations for the conduct of clinical trials in acute severe asthma. If this is not possible, the group will agree on a series of prioritized steps to achieve this aim.DiscussionThe development of an international consensus on core outcomes is an important first step towards the development of consensus guidelines and standardised protocols for randomized controlled trials (RCTs) in this population. This will enable us to better interpret and compare future studies, reduce risks of study heterogeneity and outcome reporting bias, and improve the evidence base for the management of this important condition

Langmuir–Blodgett Films of the Metal–Organic Framework MIL-101(Cr): Preparation, Characterization, and CO₂ Adsorption Study Using a QCM-Based Setup

This work reports the fabrication and characterization of Langmuir–Blodgett films of nanoparticles (size 51 ± 10 nm) of the metal organic framework MIL-101­(Cr). LB film characterization by SEM, UV–vis, GIXRD, and QCM has shown that the addition of 1 wt % of behenic acid to MOF dispersion allows obtaining dense monolayers at the air–water interface that can be deposited onto solid substrates of different nature with transfer ratios close to 1. Moreover, a QCM-based setup has been built and used for the first time to measure CO₂ adsorption isotherms at 303 K on MOF LB films, proving that LB films with MOF masses between 1.2 (1 layer) and 2.3 (2 layers) μg can be used to obtain accurate adsorption values at 100 kPa, similar to those obtained by conventional adsorption methods that require much larger MOF quantities (tens of milligrams)

Thin-Film Nanocomposite Membrane with the Minimum Amount of MOF by the Langmuir–Schaefer Technique for Nanofiltration

An innovative procedure for positioning a monolayer of hydrophilic metal organic framework (MOF) MIL-101­(Cr) (MIL, Materials of Institute Lavoisier) nanoparticles (NPs) in thin-film nanocomposite (TFN) membranes has been implemented by transferring a Langmuir–Schaefer (LS) film of the MOF in between the polyamide thin layer at the top and the cross-linked asymmetric polyimide (P84) support at the bottom. The presence and layout of the LS-MIL-101­(Cr) monolayer in the TFN membrane was confirmed by scanning transmission electron microscopy imaging with a high-angle annular dark-field detector images and X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy, and atomic force microscopy analyses. This methodology requires the smallest amount of MOF reported to date, 3.8 μg cm^–2, and promotes the formation of a defect-free ultrathin MOF film. Although conventional TFN membranes tend to show MOF agglomerates that could contribute to the formation of unselective defects, LS-TFN membranes, characterized by a homogeneous and continuous MOF coating, exhibit an optimal membrane performance, without a significant decrease in selectivity. Outstanding methanol permeances, one of the best results reported to date, of 10.1 ± 0.5 L m^–2 h^–1 bar^–1 when filtering sunset yellow and of 9.5 ± 2.1 L m^–2 h^–1 bar^–1 when filtering rose bengal have been achieved in LS-TFN membranes with a rejection higher than 90% in all cases. Methanol permeates through the polyamide and the LS-MIL-101­(Cr) monolayer, greatly enhanced by the MOF pore system, in comparison to thin-film composite and conventional TFN membranes (7.5 ± 0.7 and 7.7 ± 1.1 L m^–2 h^–1 bar^–1 when filtering sunset yellow), respectively, in which polyamide areas free of MOF NPs are present

International practice patterns of antibiotic therapy and laboratory testing in bronchiolitis

BACKGROUND AND OBJECTIVES: International patterns of antibiotic use and laboratory testing in bronchiolitis in emergency departments are unknown. Our objective is to evaluate variation in the use of antibiotics and nonindicated tests in infants with bronchiolitis in 38 emergency departments in Pediatric Emergency Research Networks in Canada, the United States, Australia and New Zealand, the United Kingdom and Ireland, and Spain and Portugal. We hypothesized there would be significant variation, adjusted for patient characteristics. METHODS: We analyzed a retrospective cohort study of previously healthy infants aged 2 to 12 months with bronchiolitis. Variables examined included network, poor feeding, dehydration, nasal flaring, chest retractions, apnea, saturation, respiratory rate, fever, and suspected bacterial infection. Outcomes included systemic antibiotic administration and urine, blood, or viral testing or chest radiography (CXR). RESULTS: In total, 180 of 2359 (7.6%) infants received antibiotics, ranging from 3.5% in the United Kingdom and Ireland to 11.1% in the United States. CXR (adjusted odds ratio [aOR] 2.3; 95% confidence interval 1.6-3.2), apnea (aOR 2.2; 1.1-3.5), and fever (aOR 2.4; 1.7-3.4) were associated with antibiotic use, which did not vary across networks (P = .15). In total, 768 of 2359 infants (32.6%) had ≥1 nonindicated test, ranging from 12.7% in the United Kingdom and Ireland to 50% in Spain and Portugal. Compared to the United Kingdom and Ireland, the aOR (confidence interval) results for testing were Canada 5.75 (2.24-14.76), United States 4.14 (1.70-10.10), Australia and New Zealand 2.25 (0.86-5.74), and Spain and Portugal 3.96 (0.96-16.36). Testing varied across networks (P < .0001) and was associated with suspected bacterial infections (aOR 2.12; 1.30-2.39) and most respiratory distress parameters. Viral testing (591 of 768 [77%]) and CXR (507 of 768 [66%]) were obtained most frequently. CONCLUSIONS: The rate of antibiotic use in bronchiolitis was low across networks and was associated with CXR, fever, and apnea. Nonindicated testing was common outside of the United Kingdom and Ireland and varied across networks irrespective of patient characteristics