Bedroom exposure to airborne allergens in the Chicago area using a patient-operated sampling device.

BACKGROUND: In current practice, allergens in vacuum-collected dust are used as surrogates for inhalable allergens. We developed an air-sampling device that can be used by patients for direct measurement of airborne allergen concentrations in their own homes. OBJECTIVE: To demonstrate the use of this device to establish allergen concentration reference ranges in a target population and to evaluate associations between patient-reported information and measured allergen concentrations. METHODS: Patients from 5 allergist's practices in the Chicagoland region were provided with instructions, questionnaires, informed consent forms, and samplers to run for 5 days in their bedrooms. Samples were collected from cartridges and assayed by multiplex immunoassays for 12 common household allergens and enzyme-linked immunosorbent assay for ragweed. RESULTS: Unique allergen profiles were obtained for 102 patient homes. Samples with allergen concentrations above the limit of detection were as follows: total dust mite, 28%; cat, 61%; dog, 64%; mouse, 12%; rat, 0%; cockroach, 4%; Alternaria, 6%; Aspergillus, 21%; birch pollen 1%; grass, 8%; and ragweed, 5%. Of those, 75 completed questionnaires, providing meta-data for further analysis. Pet allergens correlated significantly with number of pets owned. Humidity correlated with dust mite allergens, open windows with Alternaria and mouse allergens, and high-efficiency particulate air filter use with reduced levels of several allergens. Many other variables showed no significant correlations. CONCLUSION: The combination of ease of use, high air-sampling rate, and sensitive immunoassays permitted the measurement of airborne allergen concentrations in homes and establishment of reference ranges. Patient-reported information permitted identification of factors that could relate to allergen concentrations and suggested remedial measures.

A Systematic Review of Cost-Effectiveness of Treating Out of Hospital Cardiac Arrest: Implications for Resource-limited Health Systems.

Background: Out-of-hospital cardiac arrest (OHCA) is a prevalent condition with high mortality and poor outcomes even in settings where extensive emergency care resources are available. Interventions to address OHCA have had limited success, with survival rates below 10% in national samples of high-income countries. In resource-limited settings, where scarcity requires careful priority setting, more data is needed to determine the optimal allocation of resources. Objective: To establish the cost-effectiveness of OHCA care and assess the affordability of interventions across income settings. Methods: The authors conducted a systematic review of economic evaluations on interventions to address OHCA. Included studies were (1) economic evaluations (beyond a simple costing exercise); and (2) assessed an intervention in the chain of survival for OHCA. Article quality was assessed using the CHEERs checklist and data summarised. Findings were reported by major themes identified by the reviewers. Based upon the results of the cost-effectiveness analyses we then conduct an analysis for the progressive realization of the OHCA chain of survival from the perspective of decision-makers facing resource constraints. Results: 468 unique articles were screened, and 46 articles were included for final data abstraction. Studies predominantly used a healthcare sector perspective, modeled for all patients experiencing non-traumatic cardiac OHCA, were based in the US, and presented results in US Dollars. No studies reported results or used model inputs from low-income settings. Progressive realization of the chain of survival could likely begin with investments in TOR protocols, professional prehospital defibrillator use, and CPR training followed by distribution of AEDs in high-density public locations. Finally, other interventions such as indiscriminate defibrillator placement or adrenaline use, would be the lowest priority for early investment. Conclusion: Our review found no high-quality evidence on the cost-effectiveness of treating OHCA in low-resource settings. Existing evidence can be utilized to develop a roadmap for the development of a cost-effective approach to OHCA care, however further economic evaluations using context-specific data are crucial to accurately inform prioritization of scarce resources within emergency care in these settings.

Knowledge Retention From Emergency Medicine Simulation-Based Learning Curriculum for Pre-clinical Medical Students.

Introduction Traditional medical school curricula rely on textbook-based learning during the first two years, often limiting students' clinical exposure. Simulation-based learning (SBL) provides an opportunity for students to gain clinical exposure and competency with common procedures as well as to gain knowledge related to common clinical topics. Retention of factual knowledge is a current topic of discussion as medical learners often have difficulty with long-term retention. The aim of this study was to assess if students would learn, retain, and enjoy emergency medicine (EM)-focused SBL. Materials and methods We developed an EM-focused SBL curriculum consisting of four main educational events: suturing, medical stabilization, mass casualty triage, and point-of-care ultrasound (POCUS). Participants were first- and second-year healthcare students enrolled in a traditional, preclinical curriculum, who completed pre- and post-event quizzes consisting of multiple-choice questions on topics covered during the SBL scenario. We compared pre- and post-event quiz scores using a one-way paired t-test. Quizzes were readministered up to 100 days after each SBL event to test knowledge retention, and scores were compared across time by repeated-measures analysis of variance (RMANOVA). Results For suture (n=22), mass casualty (n=20), and ultrasound simulations (n=17), post-event mean quiz scores increased significantly in comparison to mean quiz scores from before the event (p≤0.05). Medical stabilization simulation post-event scores were increased but did not reach statistical significance. Data collected at 45, 74, and 94 days following the suture lab as well as 29 and 49 days after the medical evacuation event, and 20 days after the mass casualty event showed no statistical decrease in quiz means suggesting retention of knowledge among learners. Subjective assessments of participant satisfaction demonstrated an enjoyment of the events. Discussion EM-focused SBL events offered enjoyable learning opportunities for students to effectively obtain and possibly retain clinical knowledge. Conclusion SBL has the potential to improve student retention of clinical knowledge during the preclinical years and, therefore, should be further explored and implemented as a core pillar of medical education as opposed to its current state as a learning adjunct.

Surgical management of a type A aortic dissection in a pregnant patient.

Despite emphasis for emergent surgical treatment of Stanford type A aortic dissections, pregnant patients that are clinically stable may safely receive a staged approach instead, with delivery followed by delayed dissection repair.

Novel combination of GammaTile cesium-131 brachytherapy with 5-aminolevulinic acid fluorescence-guided resection in the re-irradiation of pediatric recurrent high-grade glioma: illustrative case.

BACKGROUND: Herein, the authors describe the successful utilization of 5-aminolevulinic acid (5-ALA) and the first case of GammaTile cesium-131 therapy in a pediatric patient with recurrent high-grade glioma. 5-ALA was utilized to optimize gross-total resection prior to GammaTile implantation. After conversion to an equivalent dose in 2-Gy fractions (EQD2), a composite was made of the GammaTile dose with the initial external beam radiotherapy. Two hypothetical plans consisting of a standard hypofractionated strategy for glioma reirradiation and a CyberKnife plan using GammaTile's planning target volume were developed and likewise underwent EQD2 conversion and composite plan generation with the initial radiotherapy. OBSERVATIONS: 5-ALA was useful in achieving gross-total resection with no acute toxicity from the surgery or GammaTile irradiation. When compared with the hypothetical composite doses, GammaTile's composite, axium point dose (D0.03cc) to the brainstem was 32.9 Gy less than the hypofractionated and the CyberKnife composite plans at 38.7 Gy and 40.2 Gy, respectively. The right hippocampus demonstrated a substantially reduced composite plan dose with GammaTile with a D0.03cc of 62.4 Gy versus 71.7 and 80.7 Gy for the hypofractionated and CyberKnife composite plans, respectively. LESSONS: Utilization of 5-ALA and GammaTile therapy yielded clinically superior tumor debulking and effective radiotherapy dose localization with sparing of organs at risk, respectively.

Discerning trends in multiplex immunoassay technology with potential for resource-limited settings.

BACKGROUND: In the search for more powerful tools for diagnoses of endemic diseases in resource-limited settings, we have been analyzing technologies with potential applicability. Increasingly, the process focuses on readily accessible bodily fluids combined with increasingly powerful multiplex capabilities to unambiguously diagnose a condition without resorting to reliance on a sophisticated reference laboratory. Although these technological advances may well have important implications for the sensitive and specific detection of disease, to date their clinical utility has not been demonstrated, especially in resource-limited settings. Furthermore, many emerging technological developments are in fields of physics or engineering, which are not readily available to or intelligible to clinicians or clinical laboratory scientists. CONTENT: This review provides a look at technology trends that could have applicability to high-sensitivity multiplexed immunoassays in resource-limited settings. Various technologies are explained and assessed according to potential for reaching relevant limits of cost, sensitivity, and multiplex capability. Frequently, such work is reported in technical journals not normally read by clinical scientists, and the authors make enthusiastic claims for the potential of their technology while ignoring potential pitfalls. Thus it is important to draw attention to technical hurdles that authors may not be publicizing. SUMMARY: Immunochromatographic assays, optical methods including those involving waveguides, electrochemical methods, magnetorestrictive methods, and field-effect transistor methods based on nanotubes, nanowires, and nanoribbons reveal possibilities as next-generation technologies.

Concurrent measurement of microbiome and allergens in the air of bedrooms of allergy disease patients in the Chicago area.

The particulate and biological components of indoor air have a substantial impact on human health, especially immune respiratory conditions such as asthma. To better explore the relationship between allergens, the microbial community, and the indoor living environment, we sampled the bedrooms of 65 homes in the Chicago area using 23the patient-friendly Inspirotec electrokinetic air sampling device, which collects airborne particles for characterization of both allergens and microbial DNA. The sampling device captured sufficient microbial material to enable 16S rRNA amplicon sequencing data to be generated for every sample in the study. Neither the presence of HEPA filters nor the height at which the air sampling device was placed had any influence on the microbial community profile. A core microbiota of 31 OTUs was present in more than three quarters of the samples, comprising around 45% of the relative sequence counts in each bedroom. The most abundant single organisms were Staphylococcus, with other core taxa both human and outdoor-associated. Bacterial alpha diversity was significantly increased in bedrooms that reported having open windows, those with flowering plants in the vicinity, and those in homes occupied by dogs. Porphyromonas, Moraxella, Sutterella, and Clostridium, along with family Neisseraceae, were significantly enriched in homes with dogs; interestingly, cats did not show a significant impact on microbial diversity or relative abundance. While dog allergen load was significantly correlated with bacterial alpha diversity, the taxa that significantly correlated with allergen burden did not exclusively overlap with those enriched in homes with dogs. Alternaria allergen load was positively correlated with bacterial alpha diversity, while Aspergillus allergen load was negatively correlated. The Alternaria allergen load was also significantly correlated with open windows. Microbial communities were significantly differentiated between rural, suburban, and urban homes and houses that were physically closer to each other maintained significantly more similar microbiota. We have demonstrated that it is possible to determine significant associations between allergen burden and the microbiota in air from the same sample and that these associations relate to the characteristics of the home and neighborhoods.

A simple novel device for air sampling by electrokinetic capture.

BACKGROUND: A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. RESULTS: An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 µm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. CONCLUSIONS: This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.