The New South Wales Sudden Cardiac Arrest Registry: A Data Linkage Cohort Study.

BACKGROUND: Sudden cardiac arrest (SCA) in young people aged 1 to 50 years often occurs with no presenting symptoms or risk factors prompting screening for cardiovascular disease prior to their cardiac arrest. Approximately 3,000 young Australians suffer from sudden cardiac death (SCD) each year, making this a major public health issue. However, there is significant variation in the way incidence is estimated resulting in discrepancy across reporting which impacts our ability to understand and prevent these devastating events. We describe the New South Wales (NSW) Sudden Cardiac Arrest Registry: a retrospective, data linkage study which will identify all SCAs in the young in NSW from 2009 through to June 2022. OBJECTIVE: To determine the incidence, demographic characteristics and causes of SCA in young people. We will develop an NSW-based registry that will contribute to a greater understanding of SCA including risk factors and outcomes. METHODS: The cohort will include all people who experience a SCA in the NSW community aged between 1 to 50 years. Cases will be identified using the following three datasets: the Out of Hospital Cardiac Arrest Register housed at NSW Ambulance, the NSW Emergency Department Data Collection, and the National Coronial Information System. Data from eight datasets will be collected, anonymised and linked for the entire cohort. Analysis will be undertaken and reported using descriptive statistics. CONCLUSIONS: The NSW SCA registry will be an important resource for the improved understanding of SCA and inform the widespread impacts it has on individuals, their families and society.

The Iris billiard: Critical geometries for global chaos.

We introduce the Iris billiard that consists of a point particle enclosed by a unit circle around a central scattering ellipse of fixed elongation (defined as the ratio of the semi-major to the semi-minor axes). When the ellipse degenerates to a circle, the system is integrable; otherwise, it displays mixed dynamics. Poincaré sections are presented for different elongations. Recurrence plots are then applied to the long-term chaotic dynamics of trajectories launched from the unstable period-2 orbit along the semi-major axis, i.e., one that initially alternately collides with the ellipse and the circle. We obtain numerical evidence of a set of critical elongations at which the system undergoes a transition to global chaos. The transition is characterized by an endogenous escape event, E, which is the first time a trajectory launched from the unstable period-2 orbit misses the ellipse. The angle of escape, θesc, and the distance of the closest approach, dmin, of the escape event are studied and are shown to be exquisitely sensitive to the elongation. The survival probability that E has not occurred after n collisions is shown to follow an exponential distribution.

Iso-lating optimal automated external defibrillator signage: An international survey.

Introduction: This study investigated the public's preference to a recognisable and meaningful signage for Automated External Defibrillators (AEDs) in alignment with ISO 7010 standards, aiming to identify improvements for better public awareness and response during out-of-hospital cardiac arrests (OHCA). Methods: A survey was administered via SurveyMonkey® and Heart of the Nation's social media. The survey evaluated recognition of ISO signage colors and AED symbols, and preferences for alternative AED signs. Baseline data including geographic location, industry employment, and first aid training were collected. Results: A total of 935 responses were received (Heart of the Nation's social media (n = 244) Survey Monkey's (paid, and independent of Heart of the Nation, n = 691). There were 511 from the US and Canada (54.65 %), 222 from the UK and Europe (23.76 %), 133 from the Asia Pacific (14.22 %), 6 from South America (0.64 %), 2 from the Middle East (0.21 %), and 61 from other territories (6.53 %). Among participants, 455 (48.66 %) were first aid trained. The healthcare sector was the most common employment (n = 155, 16.58 %). Only 187 (20 %) participants correctly identified the ISO AED sign. The preferred sign was a yellow sign with a red heart and blue font, chosen by 252 (27 %) participants. Conclusion: Current ISO 7010 AED signage is not widely recognised, and is only correctly interpreted by a small percentage of the public. The study suggests a need for more intuitive and visually distinct signage, such as the preferred yellow sign, to improve visibility and understanding, thereby enhancing AED accessibility and usage in OHCA.

Sex disparities in bystander defibrillation for out-of-hospital cardiac arrest.

Background: Previous studies have suggested that females experiencing out-of-hospital cardiac arrest (OHCA) receive lower rates of both bystander cardiopulmonary resuscitation (CPR) and defibrillation compared to males. Whether this disparity has improved over time is unknown. Methods: A state-wide OHCA registry in Victoria, Australia collected data over twenty years (2002-2021) regarding rates of bystander interventions in OHCA. Characteristics and outcomes of each OHCA were compared with logistic regression according to sex and time (defined in two-year periods). Results: 32,502 OHCAs were included (69.7% male). Both bystander CPR and defibrillation rates increased for females over time (p < 0.0001). There was no sex disparity in receipt of bystander CPR after adjustment for baseline differences. Females were less likely than males to receive bystander defibrillation, with sex disparity increasing from 2010 onwards (adjOR 0.26 (95%CI 0.09-0.80) in 2020-21 for females compared to males). Conclusion: Initiatives to increase bystander CPR and defibrillation have resulted in higher overall rates of bystander interventions in the last two decades and no significant sex differences in provision of bystander CPR. However, females receive less bystander defibrillation than males, and sex disparity is increasing. Strategies to promote bystander defibrillation in females experiencing OHCA with a shockable rhythm should be a priority.

Near-death experiences after cardiac arrest: a scoping review.

BACKGROUND: This scoping review aimed to characterise near-death experiences in the setting of cardiac arrest, a phenomenon that is poorly understood and may have clinical consequences. METHOD: PubMed/MEDLINE was searched to 23 July 2023 for prospective studies describing near-death experiences in cardiac arrest. PRISMA-ScR guidelines were adhered to. Qualitative and quantitative data were synthesised. Meta-analysis was precluded due to data heterogeneity. RESULTS: 60 records were identified, of which 11 studies involving interviews were included from various countries. Sample size ranged from 28-344, and proportion of female patients (when reported) was 0-50%, with mean age (when reported) ranging 54-64 years. Comorbidities and reasons for cardiac arrest were heterogeneously reported. Incidence of near-death experiences in the included studies varied from 6.3% to 39.3%; with variation between in-hospital (6.3-39.3%) versus out-of-hospital (18.9-21.2%) cardiac arrest. Individual variables regarding patient characteristics demonstrated statistically significant association with propensity for near-death experiences. Reported content of near-death experiences tended to reflect the language of the questionnaires used, rather than the true language used by individual study participants. Three studies conducted follow-up, and all suggested a positive life attitude change, however one found significantly higher 30-day all-cause mortality in patients with near-death experiences versus those without, in non-controlled analysis. CONCLUSIONS: From prospective studies that have investigated the phenomenon, near-death experiences may occur in as frequent as over one-third of patients with cardiac arrest. Lasting effects may follow these events, however these could also be confounded by clinical characteristics.

Public attitudes towards automated external defibrillators: results of a survey in the Australian general population.

Background: Swift defibrillation by lay responders using automated external defibrillators (AEDs) increases survival in out-of-hospital cardiac arrest (OHCA). This study evaluated newly designed yellow-red vs. commonly used green-white signage for AEDs and cabinets and assessed public attitudes to using AEDs during OHCA. Methods: New yellow-red signage was designed to enable easy identification of AEDs and cabinets. A prospective, cross-sectional study of the Australian public was conducted using an electronic, anonymised questionnaire between November 2021 and June 2022. The validated net promoter score investigated public engagement with the signage. Likert scales and binary comparisons evaluated preference, comfort and likelihood of using AEDs for OHCA. Results: The yellow-red signage for AED and cabinet was preferred by 73.0% and 88%, respectively, over the green-white counterparts. Only 32% were uncomfortable with using AEDs, and only 19% indicated a low likelihood of using AEDs in OHCA. Conclusion: The majority of the Australian public surveyed preferred yellow-red over green-white signage for AED and cabinet and indicated comfort and likelihood of using AEDs in OHCA. Steps are necessary to standardise yellow-red signage of AED and cabinet and enable widespread availability of AEDs for public access defibrillation.

Weak clogging in constricted channel flow.

We investigate simple models of a monodisperse system of soft, frictionless disks flowing through a two-dimensional microchannel in the presence of a single or a double constriction using Brownian dynamics simulation. After a transient time, a stationary state is observed with an increase in particle density before the constriction and a depletion after it. For a constriction width to particle diameter ratio of less than 3, the mean particle velocity is reduced compared to the unimpeded flow and it falls to zero for ratios of less than 1. At low temperatures, the particle mean velocity may vary nonmonotonically with the constriction width. The associated intermittent behavior is due to the formation of small arches of particles with a finite lifetime. The distribution of the interparticle exit times rises rapidly at short times followed by an exponential decay with a large characteristic time, while the cascade size distribution displays prominent peaks for specific cluster sizes. Although the dependence of the mean velocity on the separation of two constrictions is not simple, the mean flow velocity of a system with a single constriction provides an upper envelope for the system with two constrictions. We also examine the orientation of the leading pair of particles in front of the constriction(s). With a single constriction in the intermittent regime, there is a strong preference for the leading pair to be orientated perpendicular to the flow. When two constrictions are present, orientations parallel to the flow are much more likely at the second constriction.

Recurrence dynamics of particulate transport with reversible blockage: From a single channel to a bundle of coupled channels.

We model a particulate flow of constant velocity through confined geometries, ranging from a single channel to a bundle of N_{c} identical coupled channels, under conditions of reversible blockage. Quantities of interest include the exiting particle flux (or throughput) and the probability that the bundle is open. For a constant entering flux, the bundle evolves through a transient regime to a steady state. We present analytic solutions for the stationary properties of a single channel with capacity N≤3 and for a bundle of channels each of capacity N=1. For larger values of N and N_{c}, the system's steady state behavior is explored by numerical simulation. Depending on the deblocking time, the exiting flux either increases monotonically with intensity or displays a maximum at a finite intensity. For large N we observe an abrupt change from a state with few blockages to one in which the bundle is permanently blocked and the exiting flux is due entirely to the release of blocked particles. We also compare the relative efficiency of coupled and uncoupled bundles. For N=1 the coupled system is always more efficient, but for N>1 the behavior is more complex.

Oral Rapid HIV Testing: Implementation experiences of dental hygiene faculty and students.

Purpose: The goal of oral rapid HIV testing (ORHT) in the dental setting is to identify persons who are unaware of their positive HIV status. The purpose of this study was to describe the experiences of dental hygiene faculty and students who implemented ORHT in university-based dental hygiene clinics and to assess the facilitators and barriers to implementation of ORHT in the dental setting.Methods: Data were collected via semi-structured interviews with dental hygiene faculty and students who conducted ORHT in three dental clinics located in academic institutions. All interview sessions were audio-recorded and transcribed. An inductive approach informed by grounded theory methodology was used to code data and inform theme development. The interview sessions were completed when conceptual saturation was reached.Results: Five themes were identified by the study participants consisting of dental hygiene faculty (n= 8) and dental hygiene students (n=14). Participants felt dental hygienists are qualified to administer ORHT, which fits within their scope of practice; dental hygienists have the skills to feel comfortable offering ORHT without judgement; training is needed with ORHT administration, reading/discussing test results, and counseling for those who receive reactive results; most patients were receptive to being offered the ORHT; and patients accepted the ORHT because it was free, quick to administer and receive results, and convenient since they were already in the dental setting.Conclusion: Results from this study indicate that dental hygienists can play a key role in public health efforts to identify persons who are unaware of their HIV status.

Stochastic models of multi-channel particulate transport with blockage.

Particle conveying channels may be bundled together. The limited carrying capacity of the constituent channels may cause the bundle to be subject to blockages. If coupled, the blockage of one channel causes an increase in the flux entering the others, leading to a cascade of failures. Once all the channels are blocked, no additional particles may enter the system. If the blockages are of finite duration, the system reaches a steady state with an exiting flux that is reduced compared to the incoming one. We propose a stochastic model consisting of N c channels, each with a blocking threshold of N particles. Particles enter the system's open channels according to a Poisson process, with an equally distributed input flux of intensity Λ. In an open channel the leading particle exits at a rate µ and a blocked channel unblocks at a rate [Formula: see text], where [Formula: see text]. We present and explain the methodology of an analytical description of the behavior of bundled channels. This leads to exact expressions for the steady-state output flux, for [Formula: see text], which promises to extend to arbitrary N c and N. The results are applied to compare the efficiency of conveying a particulate stream of intensity Λ using a single, high capacity (HC) channel with multiple channels of a proportionately reduced low capacity (LC). The HC channel is more efficient at low input intensities, while the multiple LC channels have a higher throughput at high intensities. We also compare [Formula: see text] coupled channels, each of capacity N = 2 with the corresponding number of independent channels of the same capacity. For [Formula: see text], if [Formula: see text], the coupled channels are always more efficient. Otherwise the independent channels are more efficient for sufficiently large Λ.

Are patients receiving health promotion advice in the chiropractic teaching clinic setting?: an impact assessment of a brief intervention to increase advising rates and goal setting.

PURPOSE: The aim of this study was to analyze patient-reported health issues and levels of engagement, discussion of needed lifestyle changes, and goal setting with the patient's intern or staff doctor before and after a brief intervention to increase health-promoting activities in the clinic. METHODS: Patient surveys were developed and administered to outpatients before and after a brief intervention aimed at increasing staff and intern engagement with patients on health promotion measures. Patients self-reported areas of need and levels of engagement by their doctor or intern. Data were analyzed as pre- and postintervention independent, cross-sectional samples. Frequencies and chi-square assessments were performed. RESULTS: One hundred twenty-eight preintervention surveys and 162 postintervention surveys were collected. Back pain was the most common reason for being seen in the clinic (60% of patients) and most patients were white. More than 10% were smokers in both samples. Many patients reported poor diet, unhealthy weight, sleep issues, stress, or lack of regular physical activity, but 65% of the preintervention group and 72% of the postintervention group said a needed lifestyle change was discussed. Goals were set for 74% of the preintervention group and 84% of the postintervention group (p = .04). Information on lifestyle change was received by 52% of preintervention patients and 62% of postintervention patients and most were satisfied with this information. Goal setting was more common when a lifestyle change was discussed. Written information that was related to physical activity, for example, increased 350% (p < .0001). CONCLUSION: There are many opportunities for discussing needed lifestyle changes with patients. Patients self-report health behavioral issues related to physical activity, unhealthy weight, diet, stress, and sleep. More can be done in this area by this clinic, but initial assessments of impact from a brief intervention seem to have increased some levels of engagement by interns.