Project description:Out-of-hospital cardiac arrest is a leading cause of death worldwide. Rapid diagnosis and initiation of cardiopulmonary resuscitation (CPR) is the cornerstone of therapy for victims of cardiac arrest. Yet a significant fraction of cardiac arrest victims have no chance of survival because they experience an unwitnessed event, often in the privacy of their own homes. An under-appreciated diagnostic element of cardiac arrest is the presence of agonal breathing, an audible biomarker and brainstem reflex that arises in the setting of severe hypoxia. Here, we demonstrate that a support vector machine (SVM) can classify agonal breathing instances in real-time within a bedroom environment. Using real-world labeled 9-1-1 audio of cardiac arrests, we train the SVM to accurately classify agonal breathing instances. We obtain an area under the curve (AUC) of 0.9993 ± 0.0003 and an operating point with an overall sensitivity and specificity of 97.24% (95% CI: 96.86-97.61%) and 99.51% (95% CI: 99.35-99.67%). We achieve a false positive rate between 0 and 0.14% over 82 h (117,985 audio segments) of polysomnographic sleep lab data that includes snoring, hypopnea, central, and obstructive sleep apnea events. We also evaluate our classifier in home sleep environments: the false positive rate was 0-0.22% over 164 h (236,666 audio segments) of sleep data collected across 35 different bedroom environments. We prototype our proof-of-concept contactless system using commodity smart devices (Amazon Echo and Apple iPhone) and demonstrate its effectiveness in identifying cardiac arrest-associated agonal breathing instances played over the air.
Project description:ImportanceOutcomes from out-of-hospital cardiac arrests (OHCAs) remain poor. Outcomes associated with community interventions that address bystander cardiopulmonary resuscitation (CPR) remain unclear and need further study.ObjectiveTo examine community interventions and their association with bystander CPR and survival after OHCA.Data sourcesLiterature search of the MEDLINE, Embase, and the Cochrane Library databases from database inception to December 31, 2018, was conducted. Key search terms included cardiopulmonary resuscitation, layperson, basic life support, education, cardiac arrest, and survival.Study selectionCommunity intervention studies that reported on comparisons with control and differences in survival following OHCA were included. Studies that focused only on in-hospital interventions, patients with in-hospital cardiac arrest, only dispatcher-assisted CPR, or provision of automated external defibrillators were excluded.Data extraction and synthesisPooled odds ratios (ORs) and 95% CIs were estimated using a random-effects model. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.Main outcomes and measuresThirty-day survival or survival to hospital discharge and bystander CPR rate.ResultsA total of 4480 articles were identified; of these, 15 studies were included for analysis. There were broadly 2 types of interventions: community intervention alone (5 studies) and community intervention combined with changes in health services (10 studies). Four studies involved notification systems that alerted trained lay bystanders to the location of the OHCA in addition to CPR skills training. Meta-analysis of 9 studies including 21?266 patients with OHCA found that community interventions were associated with increased survival to discharge or 30-day survival (OR, 1.34; 95% CI, 1.14-1.57; I2?=?33%) and greater bystander CPR rate (OR, 1.28; 95% CI, 1.06-1.54; I2?=?82%). Compared with community intervention alone, community plus health service intervention was associated with a greater bystander CPR rate compared with community alone (community plus intervention: OR, 1.74; 95% CI, 1.26-2.40 vs community alone: OR, 1.06; 95% CI, 0.85-1.31) (P?=?.01). Survival rate, however, was not significantly different between intervention types: community plus health service intervention OR, 1.71; 95% CI, 1.09-2.68 vs community only OR, 1.26; 95% CI, 1.05-1.50 (P?=?.21).Conclusions and relevanceIn this study, while the evidence base is limited, community-based interventions with a focus on improving bystander CPR appeared to be associated with improved survival following OHCA. Further evaluations in diverse settings are needed to enable widespread implementation of such interventions.
Project description:ImportanceBystander-delivered defibrillation (hereinafter referred to as bystander defibrillation) of patients with out-of-hospital cardiac arrests (OHCAs) remains limited despite the widespread dissemination of automated external defibrillators (AEDs).ObjectiveTo examine calendar changes in bystander defibrillation and subsequent survival according to a public or a residential location of the cardiac arrest after nationwide initiatives in Denmark to facilitate bystander-mediated resuscitative efforts, including bystander defibrillation.Design, setting, and participantsThis nationwide study identified 18 688 patients in Denmark with first-time OHCA from June 1, 2001, to December 31, 2012, using the Danish Cardiac Arrest Registry. Patients had a presumed cardiac cause of arrest that was not witnessed by emergency medical services personnel. Data were analyzed from April 1, 2015, to December 10, 2016.ExposuresNationwide initiatives to facilitate bystander resuscitative efforts, including bystander defibrillation, consisted of resuscitation training of Danish citizens, dissemination of on-site AEDs, foundation of an AED registry linked to emergency medical dispatch centers, and dispatcher-assisted guidance of bystander resuscitation efforts.Main outcomes and measuresThe proportion of patients who received bystander defibrillation according to the location of the cardiac arrest and their subsequent 30-day survival.ResultsOf the 18 688 patients with OHCAs (67.8% men and 32.2% women; median [interquartile range] age, 72 [62-80] years), 4783 (25.6%) had a cardiac arrest in a public location and 13 905 (74.4%) in a residential location. The number of registered AEDs increased from 141 in 2007 to 7800 in 2012. The distribution of AED location was consistently skewed in favor of public locations. Bystander defibrillation increased in public locations from 3 of 245 (1.2%; 95% CI, 0.4%-3.5%) in 2001 to 78 of 510 (15.3%; 95% CI, 12.4%-18.7%) in 2012 (P < .001) but remained unchanged in residential locations from 7 of 542 (1.3%; 95% CI, 0.6%-2.6%) in 2001 to 21 of 1669 (1.3%; 95% CI, 0.8%-1.9%) in 2012 (P = .17). Thirty-day survival after bystander defibrillation increased in public locations from 8.3% (95% CI, 1.5%-35.4%) in 2001/2002 to 57.5% (95% CI, 48.6%-66.0%) in 2011/2012 (P < .001) in residential locations, from 0.0% (95% CI, 0.0%-19.4%) in 2001/2002 to 25.6% (95% CI, 14.6%-41.1%) in 2011/2012 (P < .001).Conclusions and relevanceInitiatives to facilitate bystander defibrillation were associated with a marked increase in bystander defibrillation in public locations, whereas bystander defibrillation remained limited in residential locations. Concomitantly, survival increased after bystander defibrillation in residential and public locations.
Project description:Objective:This study aimed to assess the benefits of adding a physician-staffed ambulance to bystander-witnessed out-of-hospital cardiac arrest using a community-based registry.Design:Population-based, retrospective cohort study.Setting:An urban city with approximately 800 000 residents.Participants:Patients aged ≥18 years with bystander-witnessed out-of-hospital cardiac arrests of medical aetiology in Niigata City, Japan, between January 2012 and December 2016, according to the Utstein style.Primary and secondary outcome measures:The primary outcome was 1-month survival with a favourable neurological outcome, defined as a cerebral performance category score of 1 or 2. We used logistic regression analysis to assess the association between favourable neurological outcome and prehospital physician involvement.Results:During the study period, a total of 4172 cardiac arrests were registered; of these, 892 patients with out-of-hospital cardiac arrest were eligible for this analysis, among whom 135 (15.1%) had prehospital physician involvement and 757 (84.9%) did not have prehospital physician involvement. The percentage of favourable neurological outcomes was 20.7% (28 of 135) in those with physician involvement and 10.4% (79 of 757) in those without physician involvement (p=0.001). Using multivariable logistic regression, prehospital physician involvement had an OR for a favourable neurological outcome of 3.44 (95% CI 1.64 to 7.23).Conclusions:Among adults with out-of-hospital cardiac arrest, adding a physician-staffed ambulance was associated with significantly greater favourable neurological outcomes than standard emergency medical services.
Project description:ObjectivesTo explore the reasons why lay community first responders (CFRs) volunteer to participate in out-of-hospital cardiac arrest response and the realities of their experience in providing this service to the community.DesignA qualitative study, using in-depth semistructured interviews that were recorded and transcribed. Thematic analysis was undertaken and credibility checks conducted.SettingNine geographically varied lay CFR schemes throughout Ireland.ParticipantsTwelve experienced CFRs.ResultsCFRs were motivated to participate based on a variety of factors. These included altruistic, social and pre-existing emergency care interest. A proportion of CFRs may volunteer because of experience of cardiac arrest or illness in a relative. Sophisticated structures and complex care appear to underpin CFR involvement in out-of-hospital cardiac arrest. Strategic and organisational issues, multifaceted cardiac arrest care and the psychosocial impact of participation were considered.ConclusionsHealth systems that facilitate CFR out-of-hospital cardiac arrest response should consider a variety of relevant issues. These issues include the suitability of those that volunteer, complexities of resuscitation/end-of-life care, responder psychological welfare as well as CFRs' core role of providing early basic life support and defibrillation in the community.
Project description:BackgroundMost studies on bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) have focused on in-hospital or short-term survival.ObjectivesThe purpose of this study was to examine the association between bystander CPR and long-term survival outcomes for OHCA.MethodsWithin the Cardiac Arrest Registry to Enhance Survival, we identified 152,653 patients with OHCA ≥65 years of age or older. Using multivariable hierarchical logistic regression, we first examined the association between bystander CPR and in-hospital survival. Then, among those surviving to discharge and linked to Medicare files, we evaluated the association between bystander CPR and long-term mortality over 5 years using multivariable Cox regression.ResultsOverall, 58,464 (38.3%) received bystander CPR. Patients receiving bystander CPR were more likely to have an OHCA that was witnessed, in a public location, and with an initial shockable rhythm. Bystander CPR was associated with a 24% higher likelihood of surviving to hospital discharge (10.2% vs 5.5%; adjusted relative risk: 1.24 [95% CI: 1.19-1.29]; P < 0.001), and this survival benefit was similar (interaction P = 0.24) for those who were 65 to 74, 75 to 84, and ≥85 years of age. Among patients surviving to hospital discharge (median follow-up of 31 months), bystander CPR was additionally associated with lower long-term mortality vs those without bystander CPR (adjusted hazard ratio: 0.78 [95% CI: 0.73-0.84]; P < 0.001), and this benefit was also consistent across age groups (interaction P = 0.13).ConclusionsIn older adults with OHCA, bystander CPR was associated with higher rates of in-hospital survival. This survival benefit was not attenuated by competing mortality risks but increased in magnitude after hospital discharge.
Project description:Importance:Out-of-hospital cardiac arrests (OHCAs) are a major public health concern and a leading cause of death worldwide. Exposure to ambient air pollution is associated with increases in morbidity and mortality and has been recognized as a leading contributor to global disease burden. Objective:To examine the association between short-term exposure to particulate matter with a diameter of 2.5 ?m or smaller (PM2.5) and the incidence of OHCAs of cardiac origin and with the development of initial cardiac arrest rhythm. Design, Setting, and Participants:This case-control study used data from cases registered between January 1, 2005, and December 31, 2016, in the All-Japan Utstein Registry, a prospective, nationwide, population-based database for OHCAs across all 47 Japanese prefectures. These OHCA cases included patients who had bystander-witnessed OHCAs and for whom emergency medical services responders initiated resuscitation before hospital transfer. A case-crossover design was employed for the study analyses. A prefecture-specific, conditional logistic regression model to estimate odds ratios was applied, and a random-effects meta-analysis was used to obtain prefecture-specific pooled estimates. All analyses were performed from May 7, 2019, to January 23, 2020. Main Outcomes and Measures:The main outcome was the association of short-term PM2.5 exposure with the incidence of bystander-witnessed OHCAs of cardiac origin. The differences in the distribution of initial cardiac arrest rhythm in OHCAs among those with exposure to PM2.5 were also examined. Results:In total, 103?189 OHCAs witnessed by bystanders were included in the final analysis. Among the patients who experienced such OHCAs, the mean (SD) age was 75 (15.5) years, and 62?795 (60.9%) were men. Point estimates of the percentage increase for a 10-?g/m3 increase in PM2.5 at lag0-1 (difference in mean PM2.5 concentrations measured on the case day and 1 day before) demonstrated a statistically significantly higher incidence of OHCA across most of the 47 prefectures, without significant heterogeneity (I2?=?20.1%; P?=?.12). A stratified analysis found an association between PM2.5 exposure and OHCAs (% increase, 1.6; 95% CI, 0.1%-3.1%). An initial shockable rhythm, such as ventricular fibrillation or pulseless ventricular tachycardia (% increase, 0.6; 95% CI, -2.0% to 3.2%), was not associated with PM2.5 exposure. However, an initial nonshockable rhythm, such as pulseless electrical activity and asystole, was associated with PM2.5 exposure (% increase, 1.4; 95% CI, 0.1%-2.7%). Conclusions and Relevance:Findings from this study suggest that increased PM2.5 concentration is associated with bystander-witnessed OHCA of cardiac origin that commonly presents with nonshockable rhythm. The results support measures to reduce PM2.5 exposure to prevent OHCAs of cardiac origin.
Project description:BackgroundStandardization of post-cardiac arrest care between emergency department arrival and intensive care unit admission can be challenging, particularly for rural centers, which can experience significant delays in interfacility transfer. One approach to addressing this issue is to form a post-cardiac arrest learning community (P-CALC) consisting of emergency department (ED) and intensive care unit (ICU) physicians and nurses who use data, shared resources, and collaboration to improve post-cardiac arrest care. MaineHealth, the largest regional health system in Maine, launched its P-CALC in 2022.ObjectiveTo explore P-CALC participants' perspectives on current post-cardiac arrest care, attitudes toward implementing a P-CALC intervention, perceived barriers and facilitators to intervention implementation, and implementation strategies.MethodsWe conducted semi-structured, individual, qualitative interviews with 16 staff from seven system EDs spanning the rural-urban spectrum. Directed content analysis was used to discern key themes in transcribed interviews.ResultsParticipants highlighted site- and system-level factors influencing current post-cardiac arrest care. They expressed both positive attitudes and concerns about the P-CALC intervention. Multiple facilitators and barriers were identified in regard to the intervention implementation. Five proposed implementation strategies emerged as important factors to move the intervention forward.ConclusionsImplementation of a P-CALC intervention to effect system-wide improvements in post-cardiac arrest care is complex. Understanding providers' perspectives on current care practices, feasibility of quality improvement, and potential intervention impacts is essential for program development.
Project description:Mitral valve prolapse (MVP) is relatively common in the general population with recently reported prevalence of 1% and familial clustering (Framingham Heart Study). However, its association with ventricular arrhythmias and sudden cardiac arrest (SCA) remains controversial.The purpose of this study was to characterize the frequency and clinical profile of patients with MVP who suffer SCA in the community.Patients with SCA cases were prospectively identified in the population-based Oregon Sudden Unexpected Death Study (population ~1 million). The presence of MVP was identified from echocardiograms recorded prior but unrelated to the SCA event. The detailed clinical profile of patients with SCA and MVP was compared with that of SCA patients without MVP to identify potential differences.A total of 729 SCA patients were evaluated over a 12-year period (mean age 69.5 ± 14.8 years; 64.6% men). MVP was observed in 17 (2.3%) prior to the SCA event (95% confidence interval 1.2%-3.4%). Mitral regurgitation was present in 14 SCA patients with MVP (82.3%) and was moderate or severe in 10 (58.8%). Compared with SCA patients without MVP, SCA patients with MVP were younger (mean age 60.9 ± 16.4 years vs 69.7 ± 14.7 years; P = .02), with fewer risk factors (diabetes 5.9% vs 46.4%; P = .001; hypertension 41.2% vs 78.9%; P = .001) or known coronary disease (29.4% vs 65.6%; P < .001).MVP was observed in a small proportion (2.3%) of SCA patients in the general population, suggesting a low risk overall. Since SCA patients with MVP were characterized by younger age and relatively low cardiovascular comorbidity, a focus on imaging for valve structure/insufficiency as well as genetics could aid future risk stratification approaches.
Project description:BACKGROUND:Women who suffer an out-of-hospital cardiac arrest receive bystander cardiopulmonary resuscitation (CPR) less often than men. Understanding public perceptions of why this occurs is a necessary first step toward equitable application of this potentially life-saving intervention. METHODS:We conducted a national survey of members of the public using Mechanical Turk, Amazon's crowdsourcing platform, to determine reasons why women might receive bystander CPR less often than men. Eligible participants were adults (?18 years) located in the United States. Responses were excluded if the participant was not able to define CPR correctly. Participants were asked to answer the following free-text question: "Do you have any ideas on why women may be less likely to receive CPR than men when they collapse in public?" Descriptive statistics were used to define the cohort. The free-text response was coded using open coding, and major themes were identified via classical content analysis. RESULTS:In total, 548 subjects were surveyed. Mean age was 38.8 years, and 49.8% were female. Participants were geographically distributed as follows: 18.5% West, 9.2% Southwest, 22.0% Midwest, 27.5% Southeast, and 22.9% Northeast. After analysis, 3 major themes were detected for why the public perceives that women receive less bystander CPR. They include the following: (1) sexualization of women's bodies; (2) women are weak and frail and therefore prone to injury; and (3) misperceptions about women in acute medical distress. Overall, 41.9% (227) were trained in CPR while 4.4% reported having provided CPR in a medical emergency. CONCLUSIONS:Members of the general public perceive fears about inappropriate touching, accusations of sexual assault, and fear of causing injury as inhibiting bystander CPR for women. Educational and policy efforts to address these perceptions may reduce the sex differences in the application of bystander CPR.