Bystander Assistance Research Articles

From Fragmentation to Integration in Emergency Medicine: Providing Care Our Patients Deserve

The emergency care systems of most communities around the world have multiple components through which patients move and which are, at best, disjointed and not well coordinated. Illnesses and injuries which begin in the community and frequently preventable often do not have the benefit of bystander assistance or dedicated immediate emergency ambulance care and arrive at Emergency Departments that are crowded. Patients often spend long hours in these Emergency Departments and, if requiring inpatient care, have to wait many hours before an inpatient bed becomes available. Those requiring further convalescent care may often find inadequate arrangements available for them to recover smoothly. The end result is delays and adverse clinical outcomes that are often not measured or even appreciated. This report discusses each of ten components of the emergency care system as in exists in most communities, including injury and illness prevention, the community burden of emergencies, bystander first responder care, ambulance-based second responder care, emergency department crowding and its contributory factors, transitions of care to the inpatient departments and community convalescent care units, coordination of emergency departments in the community, the patient’s family and, of course, the emergency patient. The effects of fragmentation in each of these components are described and strategies to address each mentioned. There is a need for a patient-centric, integrated approach to the provision of emergency care in any community which can break down the barriers created by fragmented care and provide the seamless, high-quality care that all our patients deserve.

Shortening Emergency Medical Response Time with Joint Operations of Uncrewed Aerial Vehicles with Ambulances

Problem definition: Uncrewed aerial vehicles (UAVs) are transforming emergency service logistics applications across sectors, offering easy deployment and rapid response. In the context of emergency medical services (EMS), UAVs have the potential to augment ambulances by leveraging bystander assistance, thereby reducing response times for delivering urgent medical interventions and improving EMS outcomes. Notably, the use of UAVs for opioid overdose cases is particularly promising as it addresses the challenges faced by ambulances in delivering timely medication. This study aims to optimize the integration of UAVs and bystanders into EMS in order to minimize average response times for overdose interventions. Methodology/results: We formulate the joint operation of UAVs with ambulances through a Markov decision process that captures random emergency vehicle travel times and bystander availability. We apply an approximate dynamic programming approach to mitigate the solution challenges from high-dimensional state variables and complex decisions through a neural network-based approximation of the value functions (NN-API). To design the approximation, we construct a set of basis functions based on queueing and geographic properties of the UAV-augmented EMS system. Managerial implications: The simulation results suggest that our NN-API policy tends to outperform several noteworthy rule- and optimization-based benchmark policies in terms of accumulated rewards, particularly for situations that are primarily characterized by high request arrival rates and a limited number of available ambulances and UAVs. The results also demonstrate the benefits of incorporating UAVs into the EMS system and the effectiveness of an intelligent real-time operations strategy in addressing capacity shortages, which are often a problem in rural areas of the United States. Additionally, the results provide insights into specific contributions of each dispatching or redeployment strategy to overall performance improvement. Funding: This work was supported by the National Science [Grant 1761022]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2022.0166

A roadmap to building first responder networks: Lessons learned and best practices from Belgium and Switzerland

Background/AimsLimited bystander assistance and delayed emergency medical service arrival reduce the chances of survival in cardiac arrest victims. Early basic life support through trained first responders (FR) and automatic external defibrillation both improve the outcome. Well-organized FR networks have shown promise, but guidance on effective implementation is lacking. This study evaluates two FR networks, in Belgium and in Switzerland, to identify main advancements in the development of such systems. MethodDirect comparison is made of the barriers and facilitators in the development of both FR systems from 2006 up until December 2022, and summarized within a roadmap. ResultsThe Roadmap comprises four integral steps: exploration, installation, initiation, and implementation. Exploration involves understanding the national legislation, engaging with advisory bodies, and establishing local steering committees. The installation phase focuses on FR recruitment, engaging specific professional groups such as firemen, registering public Automated External Defibrillators (AEDs), and requesting feedback. The initiation step includes implementing improvement cycles and fidelity measures. Finally, implementation expands the network, leading to increased survival rates and the integration of these practices into legislation. A significant focus is placed on FR's psychological wellbeing. Moreover, the roadmap highlights the use of efficient geo-mapping to simplify optimal AED placement and automatically assign FRs to tasks. ConclusionThe importance of FR networks for early resuscitation is increasingly recognized and various systems are being developed. Key developmental strategies of the EVapp and Ticino Cuore app system may serve as a roadmap for other systems and implementations within Europe and beyond.

Police experiences of bystander assistance in pre-hospital care of road traffic accident victims in Abuja, Nigeria: a cross-sectional study

BackgroundGlobally, most deaths from road traffic accidents (RTA) occur before the injured person reaches hospital. This mortality burden is disproportionately higher in Africa, with Nigeria having a mortality burden from RTA, at 21·4 per 100 000 people, that is six-times higher than that in high-income countries such as Norway (3·1 per 100 000 people). Bystander first aid is associated with improved survival of trauma victims and Norway has a high rate of bystander first aid to RTA victims (89%); however, data on bystander first aid for RTA victims are lacking in Nigeria. The objectives of this study were to: (1) determine the bystander assistance rate to RTA victims; (2) assess the prevalence of bystander first aid to RTA victims; and (3) evaluate bystander non-helping behaviours to RTA victims. MethodsThis was a cross-sectional study that used observer-report data collected from police officers at 31 police stations in Abuja, Nigeria. A stratified randomised sample of 428 police officers were interviewed using a structured electronic pre-tested questionnaire for data collection. The questionnaires were self-administered. We collected data on sociodemographic characteristics of police officers and they were asked to report information on bystander assistance, first aid, and non-helping behaviours during their last pre-hospital care encounters with RTA victims in Abuja. To calculate the bystander assistance rate and the prevalence of first aid, we defined bystander assistance as any activities such as calling the police or ambulance service and first aid to save the lives of RTA victims. First aid was defined as basic care such as chest compression or wound dressing given to stabilise RTA victims either at the scene of injury or during transportation to the hospital. Descriptive statistics were summarised using STATA v. 14.0. FindingsBetween Nov 21, 2018, and Dec 8, 2018, we included data from 281 police officers who had ever provided pre-hospital care to RTA victims in Abuja. The bystander assistance rate to RTA victims was 93·2% (n=262). Provision of first aid and calling the police or ambulance service were the most common form of bystander assistance (31·3% [n=82] and 28·2% [74], respectively). Other bystander assistance included provision of safety for RTA victims or first-aiders (20·2% [53]), and search and rescue for life and property near the accident scene (19·8%% [52]). The rate of bystander first aid to RTA victims was 29·2% (82). Of the bystander non-helping behaviours reported (6·8% [19]), gazing or just looking accounted for the most (68% [13]), followed by stealing victims' property (21% [4]). InterpretationThe rate of bystander first aid to RTA victims in Nigeria is significantly lower than those in high-income countries such as Norway and is likely to contribute to increased RTA mortality. Our findings highlight the need to increase community access to first aid trainings and behaviour-change interventions to improve RTA victims' health outcomes. FundingNIH and Fogarty International Center Training Grant for Partnerships to Develop Injury Research Capacities in Sub Saharan Africa (5D43TW010463-03) by Office of Global Health, University of Texas Southwestern Medical Center, USA.

The unmet needs of sudden cardiac death. The role of the wearable cardioverter defibrillator when the risk is transient or uncertain

Sudden cardiac death is defined as a natural death due to termination of cardiac activity associated with loss of consciousness, spontaneous breathing and circulation. Nowadays, the prevention of sudden cardiac death represents a major issue and many areas of uncertainty are not met by current evidences. Among those, reliable tools for risk stratification are still lacking, as well as solution for patients in which the risk of sudden cardiac death is due to a transient or correctable condition.The concept of the wearable cardioverter defibrillator is based on a potential solution for such grey areas. It merges long-term monitoring capabilities, shockable rhythm discrimination and shock delivery without the need for bystander assistance or invasive procedures. The present review aims to summarize current problems in dealing with this insidious condition, and to discuss potential options for patients in whom sudden cardiac death could be prevented more safely and cost-effectively.

MP41: Crowdsourcing to save lives: A scoping review of bystander alert technologies for out-of-hospital cardiac arrest

Introduction: Out-of-hospital cardiac arrest (OHCA) constitutes a significant global health burden, with a survival rate of only 10-12%. Early intervention is vital but limited by ambulance response times, low rates of bystander assistance, and access to AEDs. Smartphone technologies have been developed that crowdsource willing volunteers to nearby OHCAs in order to initiate resuscitation prior to ambulance arrival. We performed a scoping review to map the available literature on these crowdsourcing technologies and compared their key operational features. Methods: A search strategy was developed for five online databases: Medline, Cochrane, Embase, and Web of Science, as well as Google Scholar. We searched for primary studies and grey literature describing mobile phone technologies that alerted users of nearby cardiac arrests in the community. Two reviewers independently screened all articles and extracted relevant study information. Subsequently, we performed a search of the Google and Apple app stores, a general internet search, and consulted experts to identify all available technologies that might not be described in literature. We contacted developers for information on technology use and specifications to create a detailed features table. Results: We included 72 articles examining bystander alerting technologies from 15 countries worldwide, owing to the increasing importance of this topic. We identified 25 unique technologies, of which 18 were described in the included literature. Technologies were either text message-based systems (n = 4) or mobile phone applications (n = 21). Most (23/25) used global positioning systems to direct bystanders to victims and nearby AEDs. Response radii for alerts varied widely from 200m to 10km. Some technologies had advanced features such as video-conferencing with ambulance dispatch and detailed alert settings. Not all systems required volunteers to have first aid training. There were 18 studies examining effects on bystander intervention, all of which showed significant improvements using the technologies. However, only six studies assessed impact on survival outcomes. Key barriers discussed included false positive alerts, legal liability, and potential psychological impact on volunteers. Conclusion: Our review provides a comprehensive overview of crowdsourcing technologies for bystander intervention in out-of-hospital cardiac arrest. Future work in this growing field should focus on survival outcomes and methods of addressing barriers to implementation.

The care and transport of trauma victims by layperson emergency medical systems: a qualitative study in Delhi, India

IntroductionAmbulance-based emergency medical systems (EMS) are expensive and remain rare in low- and middle-income countries, where trauma victims are usually transported to hospital by passing vehicles. Recent developments in transportation...

Evaluation of an Accessible, Real-Time, and Infrastructure-Free Indoor Navigation System by Users Who Are Blind in the Mall of America

Introduction: This article describes an evaluation of MagNav, a speech-based, infrastructure-free indoor navigation system. The research was conducted in the Mall of America, the largest shopping mall in the United States, to empirically investigate the impact of memory load on route-guidance performance. Method: Twelve participants who are blind and 12 age-matched sighted controls participated in the study. Comparisons are made for route-guidance performance between use of updated, real-time route instructions (system-aided condition) and a system-unaided (memory-based condition) where the same instructions were only provided in advance of route travel. The sighted controls (who navigated under typical visual perception but used the system for route guidance) represent a best case comparison benchmark with the blind participants who used the system. Results: Results across all three test measures provide compelling behavioral evidence that blind navigators receiving real-time verbal information from the MagNav system performed route travel faster (navigation time), more accurately (fewer errors in reaching the destination), and more confidently (fewer requests for bystander assistance) compared to conditions where the same route information was only available to them in advance of travel. In addition, no statistically reliable differences were observed for any measure in the system-aided conditions between the blind and sighted participants. Posttest survey results corroborate the empirical findings, further supporting the efficacy of the MagNav system. Discussion: This research provides compelling quantitative and qualitative evidence showing the utility of an infrastructure-free, low-memory demand navigation system for supporting route guidance through complex indoor environments and supports the theory that functionally equivalent navigation performance is possible when access to real-time environmental information is available, irrespective of visual status. Implications for designers and practitioners: Findings provide insight for the importance of developers of accessible navigation systems to employ interfaces that minimize memory demands.

Training adult laypeople in basic life support. A systematic review.

Bystander assistance is decisive to enhance the outcomes of out-of-hospital cardiac arrest. Despite an increasing number of basic life support(BLS) training methods, the most effective formula remains undefined. To identify a gold standard, we performed a systematic review describing reported BLS training methods for laypeople and analyzed their effectiveness. We reviewed the MEDLINE database from January 2006 to July 2018 using predefined inclusion and exclusion criteria, considering all studies training adult laypeople in BLS and performing practical skill assessment. Two reviewers independently extracted data and evaluated the quality of the studies using the MERSQI (Medical Education Research Study Quality Instrument) scale. Of the 1263studies identified, 27 were included. Most of them were nonrandomized controlled trials and the mean quality score was 13 out of 18, with substantial agreement between reviewers. The wide heterogeneity of contents, methods and assessment tools precluded pooling of data. Nevertheless, there was an apparent advantage of instructor-led methods, with feedback-supported hands-on practice, and retraining seemed to enhance retention. Training also improved attitudinal aspects. While there were insufficiently consistent data to establish a gold standard, instructor-led formulas, hands-on training with feedback devices and frequent retraining seemed to yield better results. Further research on adult BLS training may need to seek standardized quality criteria and validated evaluation instruments to ensure consistency.

Abstract 285: Higher Walk Score Associated With Higher Rates of Bystander AED Use in Street-Level Cardiac Arrest

Introduction: Bystander CPR (BCPR) and AED use are crucial life-saving measures in out-of-hospital cardiac arrest (OHCA). OHCA occurring in low-income black neighborhoods are less likely to receive bystander assistance. In addition to socioeconomic disparities, characteristics of the built environment may also contribute to large variation in BCPR and bystander AED rates. Hypothesis: We hypothesized that pedestrian-friendly spaces have higher rates of BCPR and bystander AED use. Methods: Using the Cardiac Arrest Registry to Enhance Survival, we studied OHCA occurring in street/highway locations in the US in 2016. We excluded cardiac arrests that were witnessed by a 911 responder. Each incident address was assigned a 0-100 Walk Score® using an open-source algorithm and linked to census tract race and income data. We analyzed the relationship between Walk Score and key elements of bystander behavior: witness of arrest, provision of BCPR, and use of AED. Results: Of 3225 OHCA, 1666 (51.7%) were witnessed, 934 (29.0%) received BCPR, and 165 (5.1%) used an AED. After adjusting for age, gender, neighborhood median household income, and neighborhood percent black, every 10-point increase in Walk Score was associated with higher odds of bystander AED use (OR, 1.23; 95% CI, 1.14 to 1.32) but lower odds of witnessed arrest (OR, 0.95; 95% CI, 0.93 to 0.97) and BCPR (OR, 0.92; 95% CI, 0.90 to 0.95) (Table). Lower neighborhood household income predicted less BCPR and AED use; higher neighborhood black composition also predicted less BCPR. Conclusions: After adjusting for neighborhood-level race and income, OHCA occurring in walkable areas had higher rates of bystander AED use but lower rates of witnessed arrest and BCPR. The effects of built environments on bystander behavior and AED availability warrant closer investigation.

Bystander Assistance for Trauma Victims in Low- and Middle-Income Countries: A Systematic Review of Prevalence and Training Interventions

Objective: Lack of organized prehospital care may contribute to the disproportionate burden of trauma-related deaths in low- and middle-income countries (LMICs). The World Health Organization (WHO) recommends bystander training in basic principles of first aid and victim transport; however, prevalence of bystander or layperson assistance to trauma victims in LMICs has not been well-described, and organized reviews of existing evidence for bystander training are lacking. This systematic review aims to 1) describe the prevalence of bystander or layperson aid or transport for trauma victims in the prehospital setting in LMICs and 2) ascertain impacts of bystander training interventions in these settings.Methods: A systematic search of OVID Medline, Cochrane Library, and relevant gray literature was conducted. We included 1) all studies detailing prevalence of bystander-administered aid or transport for trauma victims in LMICs and 2) all randomized controlled trials and observational studies evaluating bystander training interventions. We extracted study characteristics, interventions, and outcomes data. Study quality was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.Results: Sixty-two studies detailed prevalence of bystander transport and aid. Family members, police, and bus or taxi drivers commonly transported patients; a majority of patients, up to >94%, received aid from bystanders. Twenty-four studies examined impacts of training interventions. Only one study looked at transport interventions; the remainder addressed first aid training. Interventions varied in content, duration, and target learners. Evidence was generally of low quality, but all studies demonstrated improvements in layperson knowledge and skills. Five studies reported a mortality reduction.Conclusions: Heterogeneity in data reporting and outcomes limited formal meta-analysis. However, this review shows high rates of bystander involvement in prehospital trauma care and transport in LMICs and highlights the need for bystander training. Bystander training in these settings is feasible and may have an important impact on meaningful outcomes such as mortality. Categories of involved bystanders varied by region and training interventions should be targeted at relevant groups. “Train the trainer” models appear promising in securing community engagement and maximizing participation. Further research is needed to examine the value of bystander transport networks in trauma.

Prehospital deaths from trauma: Are injuries survivable and do bystanders help?

Background and objectivesDeaths from trauma occurring in the prehospital phase of care are typically excluded from analysis in trauma registries. A direct historical comparison with Hussain and Redmond's study on preventable prehospital trauma deaths has shown that, two decades on, the number of potentially preventable deaths remains high. Using updated methodology, we aimed to determine the current nature, injury severity and survivability of traumatic prehospital deaths and to ascertain the presence of bystanders and their role following the point of injury including the frequency of first-aid delivery. MethodsWe examined the Coroners’ inquest files for deaths from trauma, occurring in the prehospital phase, over a three-year period in the Cheshire and Manchester (City), subsequently referred to as Manchester, Coronial jurisdictions. Injuries were scored using the Abbreviated-Injury-Scale (AIS-2008), Injury Severity Score (ISS) calculated and probability of survival estimated using the Trauma Audit and Research Network's outcome prediction model. ResultsOne hundred and seventy-eight deaths were included in the study (one hundred and thirty-four Cheshire, forty-four Manchester). The World Health Organisation's recommendations consider those with a probability of survival between 25–50% as potentially preventable and those above 50% as preventable. The median ISS was 29 (Cheshire) and 27.5 (Manchester) with sixty-two (46%) and twenty-six (59%) respectively having a probability of survival in the potentially preventable and preventable ranges. Bystander presence during or immediately after the point of injury was 45% (Cheshire) and 39% (Manchester). Bystander intervention of any kind was 25% and 30% respectively. Excluding those found dead and those with a probability of survival less than 25%, bystanders were present immediately after the point of injury or “within minutes” in thirty-three of thirty-five (94%) Cheshire and ten of twelve (83%) Manchester. First aid of any form was attempted in fourteen of thirty-five (40%) and nine of twelve (75%) respectively. ConclusionsA high number of prehospital deaths from trauma occur with injuries that are potentially survivable, yet first aid intervention is infrequent. Following injury there is a potential window of opportunity for the provision of bystander assistance, particularly in the context of head injury, for simple first-aid manoeuvres to save lives.

Prehospital deaths from trauma: Are injuries survivable and do bystanders help?

Abstract Background and objectives Deaths from trauma occurring in the prehospital phase of care are typically excluded from analysis in trauma registries. A direct historical comparison with Hussain and Redmond's study on preventable prehospital trauma deaths has shown that, two decades on, the number of potentially preventable deaths remains high. Using updated methodology, we aimed to determine the current nature, injury severity and survivability of traumatic prehospital deaths and to ascertain the presence of bystanders and their role following the point of injury including the frequency of first-aid delivery. Methods We examined the Coroners’ inquest files for deaths from trauma, occurring in the prehospital phase, over a three-year period in the Cheshire and Manchester (City), subsequently referred to as Manchester, Coronial jurisdictions. Injuries were scored using the Abbreviated-Injury-Scale (AIS-2008), Injury Severity Score (ISS) calculated and probability of survival estimated using the Trauma Audit and Research Network's outcome prediction model. Results One hundred and seventy-eight deaths were included in the study (one hundred and thirty-four Cheshire, forty-four Manchester). The World Health Organisation's recommendations consider those with a probability of survival between 25–50% as potentially preventable and those above 50% as preventable. The median ISS was 29 (Cheshire) and 27.5 (Manchester) with sixty-two (46%) and twenty-six (59%) respectively having a probability of survival in the potentially preventable and preventable ranges. Bystander presence during or immediately after the point of injury was 45% (Cheshire) and 39% (Manchester). Bystander intervention of any kind was 25% and 30% respectively. Excluding those found dead and those with a probability of survival less than 25%, bystanders were present immediately after the point of injury or “within minutes” in thirty-three of thirty-five (94%) Cheshire and ten of twelve (83%) Manchester. First aid of any form was attempted in fourteen of thirty-five (40%) and nine of twelve (75%) respectively. Conclusions A high number of prehospital deaths from trauma occur with injuries that are potentially survivable, yet first aid intervention is infrequent. Following injury there is a potential window of opportunity for the provision of bystander assistance, particularly in the context of head injury, for simple first-aid manoeuvres to save lives.

Bystander Intervention Prior to The Arrival of Emergency Medical Services: Comparing Assistance across Types of Medical Emergencies

Objective: To determine the situational circumstances associated with bystander interventions to render aid during a medical emergency. Methods: This study examined 16.2 million Emergency Medical Service (EMS) events contained within the National Emergency Medical Services Information System. The records of patients following a 9-1-1 call for emergency medical assistance were analyzed using logistic regression to determine what factors influenced bystander interventions. The dependent variable of the model was whether or not a bystander intervened. Results: EMS providers recorded bystander assistance 11% of the time. The logistic regression model correctly predicted bystander intervention occurrence 71.4% of the time. Bystanders were more likely to intervene when the patient was male (aOR = 1.12, 95% CI = 1.12–1.3) and if the patient was older (progressive aOR = 1.10, 1.46 age group 20-29 through age group 60–99). Bystanders were less likely to intervene in rural areas compared to urban areas (aOR = 0.58, 95% CI = 0.58–0.59). The highest likelihood of bystander intervention occurred in a residential institution (aOR = 1.86, 95% CI = 1.85–1.86) and the lowest occurred on a street or a highway (aOR = 0.96, 95% CI = 0.95–0.96). Using death as a reference group, bystanders were most likely to intervene when the patient had cardiac distress/chest pain (aOR = 11.38, 95% CI = 10.93–11.86), followed by allergic reaction (aOR = 7.63, 95% CI = 7.30–7.99), smoke inhalation (aOR = 6.65, 95% CI = 5.98–7.39), and respiration arrest/distress (aOR = 6.43, 95% CI = 6.17–6.70). A traumatic injury was the most commonly recorded known event, and it was also associated with a relatively high level of bystander intervention (aOR = 5.81, 95% CI = 5.58–6.05). The type of injury/illness that prompted the lowest likelihood of bystander assistance was Sexual Assault/Rape (aOR = 1.57, 95% CI = 1.32–1.84) followed by behavioral/psychiatric disorder (aOR = 1.64, 95% CI = 1.57–1.71). Conclusion: Bystander intervention varies greatly on situational factors and the type of medical emergency. A higher risk of patient death is likely to prompt bystander action. These novel study results can lead to more effective first aid training programs. Key words: bystander; EMS; rural; cardiac distress; trauma

Bystander Experiences at and after a Motor Vehicle Accident: A Review of the Literature

Introduction To explore what was known about the experiences of bystanders both at the scene, and following a motor vehicle accident (MVA). Understanding these experiences will further elucidate the knowledge underpinning bystander's action and their needs at the scene and in the hours, days, weeks and months following this event. Methods A search of Cumulative Index to Nursing and Allied Health Literature (CINAHL), MedLine (OVID) and Informit was undertaken using a combination of the keywords: bystander, first aid, motor vehicle accidents, car crash, car collision, lay people and witness. Thirteen articles met the selection criteria and were included in the analysis. The World Wide Web (web) was subsequently searched in response to a gap in current research on bystanders’ experiences at and following a MVA. Systematic thematic coding was used in the extraction of patterns regarding bystander experiences during and after witnessing a MVA. Results In the exploration of bystanders’ experiences during and after attending a MVA this review confirmed the presence of physical, emotional, cognitive and situational factors associated with bystander responses. Bystanders demonstrated that their response behaviours were determined by the nature of the emergency and the severity of perceived injury. In addition, bystanders weighed up the costs of helping and many felt morally responsible to offer assistance. Although there were no studies of long-term negative consequences exemplars from the web provided insight into ongoing psychological affects for bystanders. Conclusion This thematic literature analysis demonstrated the need for further research into the experiences of bystanders both during and following an MVA. Understanding bystander assistance in emergencies will allow health policy decision-makers to address the needs of both potential bystanders and those of actual bystanders during and post event.

Axial and equatorial hydrogen shifts in methyl substituted cyclohexylidenes. Stereochemically-dependent isotope effects and bystander assistance

Carbenes were generated from 4- t-butyl- cis-2-methylcyclohexanone ( 4a) and from 4- t-butyl- cis-2- trans-6-dimethylcyclohexanone ( 8a, and its corresponding 2,6-d 2 analog 8b) by conventional Bamford-Stevens reactions. Product analysis revealed that an equatorial CH 3 assists migration of a geminal H more efficiently than does an axial CH 3 by a factor of about 4.6. The primary deuterium isotope effect (k H/k D) for axial shift (I ax) is ca. 1.5 times greater than for equatorial shift (I eq) in the anchored dimethyl substituted carbene 9.

New perspectives on carbene rearrangements: migratory aptitudes, bystander assistance, and geminal efficiency. [Erratum to document cited in CA118(15):146952p

New perspectives on carbene rearrangements: migratory aptitudes, bystander assistance, and geminal efficiency. [Erratum to document cited in CA118(15):146952p

New perspectives on carbene rearrangements: migratory aptitudes, bystander assistance, and geminal efficiency

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew perspectives on carbene rearrangements: migratory aptitudes, bystander assistance, and geminal efficiencyAlex NickonCite this: Acc. Chem. Res. 1993, 26, 3, 84–89Publication Date (Print):March 1, 1993Publication History Published online1 May 2002Published inissue 1 March 1993https://doi.org/10.1021/ar00027a002RIGHTS & PERMISSIONSArticle Views473Altmetric-Citations98LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (801 KB) Get e-Alerts Get e-Alerts