Simulation of phased alerting of community first responders for cardiac arrest

by Pieter L. van den Berg, Shane G. Henderson, Hemeng Li, Bridget Dicker, Caroline J. Jagtenberg

Background

Community First Responders (CFRs) are commonly used for out-of-hospital cardiac arrests, and advanced systems send so-called phased alerts: notifications with built-in time delays. The policy that defines these delays affects both response times and volunteer fatigue.

Methods

We compare alert policies by Monte Carlo Simulation, estimating patient survival, coverage, number of alerts and redundant CFR arrivals. In the simulation, acceptance probabilities and response delays are bootstrapped from 29,307 rows of historical data covering all GoodSAM alerts in New Zealand between 1-12-2017 and 30-11-2020. We simulate distances between the patient and CFRs by assuming that CFRs are located uniformly at random in a 1-km circle around the patient, for different CFR densities. Our simulated CFRs travel with a distance-dependent speed that was estimated by linear regression on observed speeds among those responders in the above-mentioned data set that eventually reached the patient.

Results

The alerting policy has a large impact on the four metrics above, and the best choice depends on volunteer density. For each volunteer density, we are able to identify a policy that improves GoodSAM New Zealand’s current policy on all four metrics. For example, when there are 30 volunteers within 1 km from the patient, sending out alerts to 7 volunteers and replacing each volunteer that rejects by a new one, is expected to save 10 additional lives per year compared to the current policy, without increasing volunteer fatigue. Our results also shed light on polices that would improve one metric while worsening another, for example, when there are 10 volunteers within 1 km from the patient, dispatching them all immediately increases our survival estimate by 11% compared to the current policy, with the downside of also increasing the redundant arrivals by 137%.

Conclusions

Monte Carlo simulation can help CFR system managers identify a good policy before implementing it in practice. We recommend balancing survival and volunteer fatigue, aiming to ultimately further improve a CFR system’s effectiveness.

Spinal cord perfusion pressure protocol for acute spinal cord injury: Pragmatic implementation and early results at two sites

by John Paul G. Kolcun, Ricky M. Ditzel Jr, Bradley L. Kolb, Ricardo B. V. Fontes, P. B. Raksin

Study design

Retrospective chart review.

Objective

Describe safety/feasibility of implementing a novel clinical protocol for acute spinal cord injury (SCI) management.

Summary of background data

Spinal cord perfusion pressure (SCPP) has emerged as a promising target for the medical management of SCI patients. We report our early experience implementing a pragmatic SCPP-driven clinical protocol to supplant conventional mean arterial pressure (MAP) monitoring in the setting of acute SCI.

Methods

We retrospectively reviewed charts of all SCI patients managed by our SCPP protocol since its adoption at two clinical sites as of 2/1/2023. The SCPP protocol was applied for all adult SCI patients of any injury grade, at any injury level with cord tissue involvement. Intrathecal pressure (ITP) was transduced by lumbar drain (LD). MAP was determined from invasive blood pressure recordings. SCPP was calculated as the difference between MAP and ITP, with an SCPP goal of >65mmHg.

Results

Eighteen patients have been treated since our SCPP protocol was adopted. Patients were predominately male (77.8%); the average age was 52.0 ± 16.2 years. Most injuries involved the cervical segment (72.2%), all of which were manifest clinically as central cord syndrome. The most common presenting injury severity was ASIA Impairment Scale D (44.4%).All patients underwent surgical intervention. There were no complications related to surgery, LD placement, or LD maintenance/ITP transduction during hospitalization. The SCPP protocol was continued for an average 5.2 ± 1.8 days. Eight patients required vasopressor support (44.4%) during that period, for an average 3.1 ± 2.1 days. Five patients underwent therapeutic CSF drainage to augment SCPP (27.8%). All patients maintained an average SCPP above goal for the duration of monitoring.

Conclusions

This study further establishes the safety and feasibility of monitoring SCPP via LD measurement of ITP in acute SCI patients treated by clinical protocol at two clinical sites. There were no complications related to LD placement/maintenance or SCPP monitoring.

Transscleral photodynamic therapy with a chlorin e6: An experimental study of exposure parameters and therapeutic window

by Ernest V. Boiko, Elena V. Samkovich, Irina E. Panova, Alexander A. Ivanov, Sergey B. Shevchenko, Sergey L. Vorobyev, Elizaveta S. Kalashnikova, Victoria G. Gvazava, Elizaveta A. Masian, Alexandra E. Kim

Purpose

To define optimal exposure parameters and the therapeutic window for transscleral photodynamic therapy (TSPDT) with chlorin e6 by evaluating clinical, histological, and thermal effects of subthreshold, therapeutic, and suprathreshold settings in rabbit eyes.

Methods

The study was conducted on 21 healthy rabbits. TSPDT was performed using a 660 nm laser and chlorin e6 (2.5 mg/kg). Transscleral probes (5 mm: 0.1 W, 0.17 W, 0.3 W; 10 mm: 0.3 W, 0.6 W) with integrated thermosensors were used. Enucleation and histological analysis were performed 14 days post-irradiation.

Results

Fundus examination on day 14 revealed distinct treatment zones correlating with laser settings. The therapeutic window was defined as 0.14–0.17 W (5 mm probe; power density: 0.693–0.866 W/cm²; energy density: 415.8–519.6 J/cm²) and 0.48–0.6 W (10 mm probe; 0.611–0.764 W/cm²; 366.6–458.4 J/cm²) with 600 s exposure time, achieving selective choroidal damage without scleral or retinal injury (ΔT ≤ 4.5°C). Suprathreshold settings (≥0.3 W for 5 mm; ≥ 0.6 W for 10 mm) induced retinal necrosis (up to 50%) and scleral coagulation (ΔT ≥ 8°C) with power densities exceeding 0.866 W/cm² (5 mm) and 0.764 W/cm² (10 mm).

Conclusion

TSPDT with chlorin e6 enables selective targeting of intraocular pathological tissues while preserving scleral and retinal integrity. Defining the therapeutic window and using real-time thermal monitoring enhances treatment safety. These findings lay a foundation for clinical protocols for uveal melanoma and other intraocular tumors.

Increased brain coverage and efficiency when measuring current-induced magnetic fields by use of simultaneous multi-slice echo-planar MRI

by Teresa Cunha, Fróði Gregersen, Lars G. Hanson, Axel Thielscher

Purpose

Magnetic resonance current density imaging (MRCDI) can non-invasively validate electric field simulations in volume conductor head models. Weak electric currents are injected using scalp electrodes while measuring the MR phase perturbations caused by the tiny magnetic fields (1–2 nT) induced by the current flow in tissue. MRCDI generally has a low signal-to-noise ratio, making it susceptible to technical imperfections and physiological noise. In this technical note, we tested and optimized simultaneous multi-slice (SMS) EPI for time-efficient and robust brain MRCDI.

Methods

MRCDI data was acquired in a phantom and five human brains using SMS-EPI optimized for measuring current-induced phase perturbations. Multiband factors and interslice gaps were systematically varied and the resulting image quality assessed. In particular, the impact of interslice signal leakage on the measured phase was tested.

Results

Current-free acquisitions showed the expected noise amplification with decreasing interslice distances. However, physiological noise generally dominated the human data, masking potential SMS-related penalties and making the overall noise levels identical to single-slice EPI for interslice gaps of at least 12 mm and multiband factors between 3 and 5. Upon application of electric currents, the phantom data revealed subtle artifacts for multiband factors 5 and 6, even for large gaps. Nevertheless, artifacts were absent in the human brain for multiband factors up to 5, where the performance of SMS-EPI approached that of single-slice measurements for sufficient interslice distances.

Conclusion

Optimized SMS-EPI with multiband factors up to 5 and minimum interslice gaps of 12 mm performs on par with single-slice EPI, making it attractive for increasing brain coverage in MRCDI.

“You could get the best of both breeds or the worst of both”: UK public attitudes towards crossbreeding in dogs - with a specific focus on brachycephalic dogs

by Elizabeth Youens, Dan G. O’Neill, Zoe Belshaw, Johanna Neufuss, Mickey S. Tivers, Rowena M. A. Packer

Extreme conformation and reduced genetic diversity are recognised to lead to severely reduced health, welfare and longevity in certain dog breeds. There is growing interest in applying strategic crossbreeding to promote more moderate conformations and greater genetic diversity within currently problematic breeds. Crossbreeding could therefore lead to more rapid and effective improvements in welfare compared to current practices of within-breed selection. Deliberate crossbreeding between distinct different dog breeds is not a new concept; it was historically commonly used to create the current pure breeds, to increase genetic diversity and to bring new physical and/or temperament traits into existing breeds. However, a recent surge in the popularity of ‘designer crossbreeds’ (intentional crosses between established purebreds) has elicited fresh interest around the potential positives and negatives of crossbreeding practices. Further research on crossbred brachycephalic dogs is urgently required for a greater understanding of the motivators and barriers to their acquisition. An online survey explored factors that motivate dog breed choice and acquisition of both crossbreed and purebred dogs. In addition, the survey used both closed and open questioning to explore the UK public’s perceptions of crossbreeding, specifically (i) between a brachycephalic breed and a non-brachycephalic breed, and (ii) between two non-brachycephalic breeds. Free-text results were analysed using content analysis and subsequently quantified. Results from 4,899 participants identified that key motivators to acquire a brachycephalic crossbreed vs a brachycephalic purebred included perceptions of improved health, including the reduction in risk of breed and conformation-related disorders, and increased genetic diversity. However, the desire to acquire a purebred dog, or even a specific breed, remained a significant barrier to crossbreed acquisition, alongside concerns surrounding the ethics of crossbreeding. Other barriers included perceived negative changes to appearance and temperament of the offspring from crossbreeding. The current study identified a common set of acquisition decision-making factors across all ownership groups, including desiring a dog who the owner perceives to enjoy being loved and to enjoy physical affection, but further demonstrated that good health is of motivational low priority to some dog owners, particularly to owners of purebred brachycephalic dogs. The mix of positive and negative public perceptions and beliefs around crossbreeding and crossbreed dogs demonstrate the need for further research into the health, temperament and appearance of brachycephalic crossbreed dogs. The suitability of crossbreed dogs as an alternative to certain current purebred breeds with high risk of genetic or conformational disorders depends on both public desire and on evidence-based selection of suitable breeds to encourage crosses which maximise canine welfare.

Evaluating the clinical care, quality of life and overall experiences of patients with primary biliary cholangitis (PBC) during the pandemic: A Canadian mixed-methods study

by Elizabeth Baguley, Madelyn Knaub, Jessica VanDyke, Gideon Hirschfield, Mark G. Swain, Gail Wright, Deirdre McCaughey, Abdel Aziz Shaheen

Pandemic restrictions impacted healthcare, particularly during the first year. We evaluated the impact of the pandemic on quality of life and clinical care among patients with primary biliary cholangitis (PBC). This mixed-methods study administered quality of life surveys (Fear of COVID-19 Scale [FCV-19S], EuroQol 5-dimension 3-level [EQ-5D-3L], 29-item Patient-Reported Outcomes Measurement Instrument Survey [PROMIS-29]) and a PBC Care Delivery questionnaire to 348 Canadian PBC patients, followed by two focus groups with patients (n = 14) and stakeholders (n = 3). Quality of life scores were compared among sub-groups (i.e., care delays and pandemic appointment type) and with various reference populations. Most participants were female (94.0%) and Caucasian (88.2%), with a median age of 63.0 years (IQR: 55.9–71.2). During the pandemic, 75.8% had the majority (≥ 50%) of their hepatologist appointments virtually, but only 22.4% preferred to continue with virtual care post-pandemic. Participants with care delays had worse scores on the FCV-19S (p = 0.014), EQ-5D-3L (p = 0.009), and PROMIS-29 (i.e., fatigue, anxiety, sleep disturbance, ability to participate in social roles and activities, p p 

Effect of returning home on university student hunger during South African COVID-19 lockdown

by Fezile Wagner, Unathi Kolanisi, Ryan G. Wagner, Lerato P. Makuapane, Mxolisi Masango, Francesc Xavier Gómez-Olivé

The COVID-19 pandemic exacerbated hunger levels in South Africa, with an increase from 10% pre-pandemic to 23% during the pandemic. Pre-pandemic national and global research identified university students to be more vulnerable to hunger compared to the general population. This elevated risk is commonly associated with prevalent financial mismanagement in this group. However, research investigating the prevalence of hunger during the pandemic among this at-risk group is limited. This cross-sectional study aimed to assess the prevalence and determinants of hunger among students at a South African university during the COVID-19 lockdown, with particular focus on the effect of returning home. An online, self-administered survey produced a sample of 596 students. The Household Hunger Scale (HHS) was used to assess hunger. Most students (84%) who resided in on- or off-campus residences before the lockdown returned home during the lockdown. The weighted prevalence of hunger during lockdown was 16.4% (95%CI 13.6%, 19.6%). Bivariate analyses found living alone to be significantly associated with hunger, while multivariate analyses found that first-generation students (adjusted odds ratio (aOR) = 1.78; 95%CI: 1.04, 3.07, p = 0.015), financial aid recipients (aOR = 2.69; 95%CI: 1.47, 4.91, p = 0.001), and those experiencing financial stress/worry (aOR = 3.38; 95%CI: 1.85, 6.18, p 

Testing oral nicotine pouches versus nicotine replacement therapy for cigarette harm reduction in Appalachia: The ARISE study protocol

by Amy Wermert, Theodore M. Brasky, Alison M. Newton, Alice Hinton, Hayley Curran, Amy K. Ferketich, Matthew J. Carpenter, Peter G. Shields, Patrick Tomko, Theodore L. Wagener, Brittney Keller-Hamilton

Background

With the highest cancer incidence and mortality rates in the country, rural Appalachia has experienced a decades-long health decline, due in part to high smoking rates. Cigarette smoking prevalence exceeds 30% in much of the region. Oral nicotine pouches (ONPs), which contain nicotine but no tobacco, present an unexplored opportunity to reduce cigarette smoking and cancer incidence.

Objectives

We outline the protocol for the Appalachian Research to Impact Smoking’s Effects (ARISE) study, a randomized controlled trial to determine whether ONPs affect cigarette smoking patterns short- and long-term, and to evaluate their abuse liability versus nicotine replacement therapy (NRT) in a large sample of Appalachian smokers (clinicaltrials.gov: NCT06763536).

Methods

Between 2025 and 2029, we will recruit 1,000 adult smokers living in rural Appalachian counties across 11 states. Participants will be identified via media outreach, mobile cancer screening, community events, and respondent-driven sampling, then randomized to ONP or NRT and complete four study phases: Baseline, Sampling, Switch, and Observation. In the Sampling phase, participants will receive varied flavors and nicotine strengths of their assigned product and select preferred options for use. During the Switch Phase, they will attempt to quit smoking and switch completely to their assigned product. The Observation phase will monitor tobacco use after discontinuation of study products. Study procedures will be conducted online and by mail, including surveys, expired carbon monoxide verification, and product delivery. The primary outcome is 7-day biochemically verified cigarette abstinence at the end of the Switch Phase. Secondary outcomes include switching rates, product appeal, craving, withdrawal, dependence, and purchases during the Observation phase. An intention-to-treat log-binomial regression model will estimate the effect of intervention assignment on cigarette abstinence.

Conclusions

Results will inform whether and how ONPs should be regulated, approached clinically, and used in public health interventions to reduce the burdens of cigarette smoking in Appalachia.

Patterns of symptom deterioration can support multimorbidity management in COPD: Perspectives of patients and healthcare professionals

by Sanne H. B. van Dijk, Marjolein G. J. Brusse-Keizer, Bente Rodenburg, Anke Lenferink

Introduction

Comorbidities significantly complicate COPD management. Remote monitoring could aid real-time disease and symptom management, assisting both patients with multimorbidity and healthcare professionals (HCPs). This study aimed to explore how insight in patterns of symptom deterioration, derived from remote monitoring, could enhance multimorbid COPD management as perceived by patients and HCPs.

Methods

Using daily symptom data collected via a mobile diary in the prospective RE-SAMPLE cohort study, patterns of symptom deterioration of COPD, chronic heart failure, anxiety, and depression were visualized per patient (follow-up duration of ≥4 months). Semi-structured individual interviews were conducted with Dutch patients with COPD and ≥1 comorbidity, and with HCPs from pulmonology, cardiology, and medical psychology who were involved in care for patients with multimorbidity. Interviews addressed current multimorbid COPD management, its challenges, and the way pattern visualizations of symptoms deterioration could support disease management. Transcripts were thematically analyzed using an inductive approach.

Results

7 patients (69–80 years, 4 men) and 7 HCPs were interviewed in the hospital (patients and HCPs), at home (patients) or online (HCPs). Three overarching themes were identified, representing the elements of multimorbid COPD management that could be supported by the pattern visualizations: 1) relationship between diseases, 2) decision-making, and 3) self-management. According to patients and HCPs, pattern visualizations can be an informative source to explain the relation between COPD and comorbidities, function as a conversation starter facilitating communication between patients and HCPs as well as between medical disciplines, and educate patients in adequately recognizing their care needs.

Conclusion

Three elements of personalized multimorbid COPD management were identified through qualitative analysis, which can all be supported by visualizing patterns of symptom deterioration via remote monitoring. The visualizations could enhance patients’ understanding of their diseases, improve shared decision-making, improve in-hospital multidisciplinary collaboration, and support multimorbid COPD (self-)management.

Using participatory methods to develop a narrative intervention to alleviate distress in children hospitalised with TB in South Africa: The DIMPle project

by Caitlin D. October, Dzunisani P. Baloyi, Lario Viljoen, Rene Raad, Dillon T. Wademan, Megan Palmer, Juli Switala, Michaile G. Anthony, Karen Du Preez, Petra De Koker, Anneke C. Hesseling, Bronwyne Coetzee, Graeme Hoddinott

Children who are hospitalised for tuberculosis (TB) experience challenges that put them at risk of developing emotional, behavioural, and social difficulties. In this methodological paper, we showcase the development of a narrative intervention toolkit with key components of the resulting version 1.0 tool. The study design was participatory and pragmatic, with researchers working with the routine staff of TB hospital wards, children admitted and their caregivers, to iteratively understand and improve children’s experiences of hospitalisation. The project included three phases: (1) a situational analysis to map children and healthcare providers’ perspectives on priorities and potential intervention components, (2) co-development of a beta-version of the intervention, and (3) piloting and incremental refinement toward a version 1.0 of the intervention. The intervention toolkit combined a series of activities alongside the story of ‘Courageous Curly’ to facilitate children’s engagement with their own experiences of hospitalisation, including psychosocial and treatment challenges, captured, and described throughout data collection. We found that dividing the story into short chapters facilitated children’s engagement with the section of story that is being told on a specific day. Each chapter of the story follows/mimics a different stage children can expect during their treatment journey while hospitalised for TB care. Implementation and evaluation of such interventions can mitigate the psychosocial impact of TB in children and inform policies to improve their overall TB care.

Seeing is believing: Understanding the experiences and needs of marginalized communities living through successive disasters using photovoice

by Laura de la Roche, Carlos G. Fuentes, Ailiya Z. Jafry, Omolola E. Adepoju

Introduction

Reports indicate increasing prevalence rates of successive natural disasters, and the negative impact on existing infrastructures are well documented. However, factors impacting outcomes on both communities and individuals remain unclear. For historically underserved communities, the effects of disasters are exacerbated by pre-existing barriers that make efforts to recovery difficult. Thus, understanding the nuance of their circumstances and experience is crucial to helping build resilience in these communities and inform preparedness and response efforts.

Objective

Through this study, we sought to qualitatively understand the lived experience of historically underserved communities in the context of natural disasters to support the development and/or adoption of resources.

Methods

Photovoice was used to guide semi-structured interviews with participants recruited from three communities (Kashmere Gardens, Greater Third Ward, Greater Fifth Ward) in Houston, TX. Reflexive thematic analysis was employed to generate themes accurately depicting participant experiences. Reflexivity, persistent observation, and triangulation were employed to increase trustworthiness in analysis.

Results

Five key themes emerged from analysis: 1) Acute and long-term damage from natural disasters requires sustained recovery efforts; 2) Gaps and opportunities exist in city, state, and federal support mechanisms; 3) Strengthening and expanding support networks and community resources after extreme weather events is critical; 4) Need to address structural barriers to disaster preparedness and coping; and 5) Recognizing and mitigating the broad mental health impacts of natural disasters.

Conclusion

The lived experiences of individuals from historically underserved communities in Houston highlight a complex interaction of psychosocial, structural, and cultural factors that influence both community resilience and vulnerability. Understanding this interplay is crucial to informing policy efforts that prioritize resilience building in these communities. Implications from these findings are discussed.

Automatic uterus segmentation in transvaginal ultrasound using U-Net and nnU-Net

by Dilara Tank, Bianca G. S. Schor, Lisa M. Trommelen, Judith A. F. Huirne, Iacer Calixto, Robert A. de Leeuw

Purpose

Transvaginal ultrasound (TVUS) is pivotal for diagnosing reproductive pathologies in individuals assigned female at birth, often serving as the primary imaging method for gynecologic evaluation. Despite recent advancements in AI-driven segmentation, its application to gynecological ultrasound still needs further attention. Our study aims to bridge this gap by training and evaluating two state-of-the-art deep learning (DL) segmentation models on TVUS data.

Materials and methods

An experienced gynecological expert manually segmented the uterus in our TVUS dataset of 124 patients with adenomyosis, comprising still images (n = 122), video screenshots (n = 472), and 3D volume screenshots (n = 452). Two popular DL segmentation models, U-Net and nnU-Net, were trained on the entire dataset, and each imaging type was trained separately. Optimization for U-Net included varying batch size, image resolution, pre-processing, and augmentation. Model performance was measured using the Dice score (DSC).

Results

U-Net and nnU-Net had good mean segmentation performances on the TVUS uterus segmentation dataset (0.75 to 0.97 DSC). We observed that training on specific imaging types (still images, video screenshots, 3D volume screenshots) tended to yield better segmentation performance than training on the complete dataset for both models. Furthermore, nnU-Net outperformed the U-Net across all imaging types. Lastly, we report the best results using the U-Net model with limited pre-processing and augmentations.

Conclusions

TVUS datasets are well-suited for DL-based segmentation. nnU-Net training was faster and yielded higher segmentation performance; thus, it is recommended over manual U-Net tuning. We also recommend creating TVUS datasets that include only one imaging type and are as clutter-free as possible. The nnU-Net strongly benefited from being trained on 3D volume screenshots in our dataset, likely due to their lack of clutter. Further validation is needed to confirm the robustness of these models on TVUS datasets. Our code is available on https://github.com/dilaratank/UtiSeg.