83 research outputs found
Role of Adaptive Team Coordination during Cardiopulmonary Resuscitation
Get PDFPlus de 200 000 patients en Amérique du Nord subissent un arrêt cardiaque à l’hôpital chaque année, mais moins de 25 % des patients survivent jusqu’à leur congé de l’hôpital. Lorsque le coeur aux battements arythmiques d’un patient ne parvient pas à faire circuler efficacement le sang, une équipe de secouristes procèdent à des interventions vitales définies en fonction d’algorithmes de réanimation cardiorespiratoire (RCR). Depuis l’adoption des lignes directrices de l’American Heart Association (AHA) il y a plus de 30 ans, les travaux de recherche ont principalement porté sur l’amélioration des taux de survie grâce à l’efficacité des tâches techniques de RCR. Au cours de la dernière décennie, une plus grande importance a été accordée aux facteurs associés à la performance d’équipe. Outre les facteurs propres au patient, les chances de survie dépendent du délai de traitement et de la qualité de la RCR que vient compliquer l’interaction de multiples intervenants qui tentent d’orchestrer des mesures de secours concurrentes. Ainsi, la coordination et le travail d’équipe inefficaces font partir des plus grands obstacles à une réanimation réussie en équipe. Dans le cadre de la présente thèse, la relation entre les différents mécanismes de coordination et le résultat technique de la RCR, mesurée en temps passif dans deux contextes de recherche empirique de réanimation simulée, a été mise à l’essai. Les résultats laissent croire que si l’action explicite constitue la caractéristique déterminante des mécanismes de coordination utilisés en réanimation cardiaque en équipe, les équipes qui performent le mieux coordonnent leurs activités de manière différente de celles qui performent le moins bien, et qu’il existe un lien important entre les tendances en matière de mécanismes de coordination et la réussite de la RCR, qui change en fonction des exigences de la tâche. Ces résultats combinés permettent d’établir un cadre de coordination proposé pour les soins de réanimation actifs et de proposer des aspects pratiques pour la formation en RCR et une contribution méthodologique aux futurs travaux de recherche.In-hospital cardiac arrest affects over 200,000 patients in North America each year, but less than 25% of patients survive to hospital discharge. When a patient’s arrhythmic heart is unable to effectively circulate blood, a team of rescuers provide lifesaving interventions according to Cardiopulmonary Resuscitation (CPR) rescue algorithms. Since the inception of the American Heart Association (AHA) CPR guidelines over 30 years ago, research pursuits to improve survival rates have primarily focused on the technical tasks such as CPR technique. Over the past decade, there has been increased focus on team performance related to treatment delays and CPR quality, touting ineffective coordination and teamwork as some of the largest obstacles to successful team resuscitation. The objective of this work was to validate a proposed framework outlining the relationship among explicit and implicit coordination mechanisms required for successful CPR performance: minimal interruptions (hands-off ratio), rapid initiation of chest compressions and defibrillation. The framework was tested in two independent studies of simulated adult and pediatric resuscitation of in-hospital cardiac arrest. The results showed that while team performance improved over time, the main Explicit and Implicit coordination type patterns were stable. Instead, small shifts occurred within the Information and Action coordination sub-types. Explicit coordination was dominant throughout all resuscitation scenarios, but only Implicit coordination was associated with better hands-off ratio performance. In both studies, higher performing teams coordinated differently than lower performing teams and there was a significant relationship between the patterns of coordination mechanisms and CPR performance. The combined results are used to refine a proposed coordination framework for acute resuscitation care and propose practical implications for CPR training and methodological contribution for future research
Qualitative, rather than quantitative, differences between HLA-DQ alleles affect HLA-DQ immunogenicity in organ transplantation
Get PDFEpitope; Histocompatibility; ImmunogenicityEpĂtop; Histocompatibilitat; ImmunogenicitatEpĂtopo; Histocompatibilidad; InmunogenicidadProlonging the lifespan of transplanted organs is critical to combat the shortage of this life-saving resource. Chronic rejection, with irreversible demise of the allograft, is often caused by the development of donor-specific HLA antibodies. Currently, enumerating molecular (amino acid) mismatches between recipient and donor is promoted to identify patients at higher risk of developing HLA antibodies, for use in organ allocation, and immunosuppression-minimization strategies. We have counseled against the incorporation of such approaches into clinical use and hypothesized that not all molecular mismatches equally contribute to generation of donor-specific immune responses. Herein, we document statistical shortcomings in previous study design: for example, use of individuals who lack the ability to generate donor-specific-antibodies (HLA identical) as part of the negative cohort. We provide experimental evidence, using CRISPR-Cas9-edited cells, to rebut the claim that the HLAMatchmaker eplets represent “functional epitopes.” We further used unique sub-cohorts of patients, those receiving an allograft with two HLA-DQ mismatches yet developing antibodies only to one mismatch (2MM1DSA), to interrogate differential immunogenicity. Our results demonstrate that mismatches of DQα05-heterodimers exhibit the highest immunogenicity. Additionally, we demonstrate that the DQα chain critically contributes to the overall qualities of DQ molecules. Lastly, our data proposes that an augmented risk to develop donor-specific HLA-DQ antibodies is dependent on qualitative (evolutionary and functional) divergence between recipient and donor, rather than the mere number of molecular mismatches. Overall, we propose an immunological mechanistic rationale to explain differential HLA-DQ immunogenicity, with potential ramifications for other pathological processes such as autoimmunity and infections.Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number R01AI170728. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work was further supported by grants from the Michael Abecassis Transplant Innovation Endowment (2019, and 2021), and by a generous contribution from the Paul I Terasaki Memorial Research Fund
Role Allocation and Team Structure in Command and Control Teams Topic 4 (Primary) Experimentation, Metrics, and Analysis Topic 2 Organizational Concepts and Approaches
Get PDFDefence and security organizations are increasingly faced with uncertain and dynamic global security environments. Often highly structured in nature, command and control (C2) in these organizations may not traditionally allow for the adaptability and flexibility required in these complex situations. In response, models of more agile, decentralized organizations -such as Edge organizations -have been proposed. To further the understanding of these organizations and their potential benefits and limitations, we sought to examine how edge-like teams spontaneously adopt and organize roles when engaging in complex, collaborative activities in the context of crisis management situations. A forest firefighting simulation was used to compare functional (explicitly assigned roles) to edge-like (no assigned roles) organizations. Four-person teams completed scenarios characterized by the occurrence of sudden and critical events. Behavioural indicators associated with various roles in the simulation (e.g., operations, resources management, search and rescue) were measured, and we assessed the extent to which these indicators matched when comparing functional teams to edge-like teams. A behavioural indicator matching across the two conditions would indicate that edge-like teams adopted a similar structure as functional teams. The results suggest edge-like teams allocate role differently from functional teams, but for a given team that allocation remain relatively stable once established. The findings are discussed with regards to team effectiveness and agility in complex C2 environments
Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults
Get PDFCitation: Wong, C. N., Chaddock-Heyman, L., Voss, M. W., Burzynska, A. Z., Basak, C., Erickson, K. I., . . . Kramer, A. F. (2015). Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults. Frontiers in Aging Neuroscience, 7, 10. doi:10.3389/fnagi.2015.00154Higher cardiorespiratory fitness is associated with better cognitive performance and enhanced brain activation. Yet, the extent to which cardiorespiratory fitness-related brain activation is associated with better cognitive performance is not well understood. In this cross-sectional study, we examined whether the association between cardiorespiratory fitness and executive function was mediated by greater prefrontal cortex activation in healthy older adults. Brain activation was measured during dual-task performance with functional magnetic resonance imaging in a sample of 128 healthy older adults (59-80 years). Higher cardiorespiratory fitness was associated with greater activation during dual-task processing in several brain areas including the anterior cingulate and supplementary motor cortex (ACC/SMA), thalamus and basal ganglia, right motor/somatosensory cortex and middle frontal gyrus, and left somatosensory cortex, controlling for age, sex, education, and gray matter volume. Of these regions, greater ACC/SMA activation mediated the association between cardiorespiratory fitness and dual-task performance. We provide novel evidence that cardiorespiratory fitness may support cognitive performance by facilitating brain activation in a core region critical for executive function
Qualitative, rather than quantitative, differences between HLA-DQ alleles affect HLA-DQ immunogenicity in organ transplantation
Get PDFProlonging the lifespan of transplanted organs is critical to combat the shortage of this life-saving resource. Chronic rejection, with irreversible demise of the allograft, is often caused by the development of donor-specific HLA antibodies. Currently, enumerating molecular (amino acid) mismatches between recipient and donor is promoted to identify patients at higher risk of developing HLA antibodies, for use in organ allocation, and immunosuppression-minimization strategies. We have counseled against the incorporation of such approaches into clinical use and hypothesized that not all molecular mismatches equally contribute to generation of donor-specific immune responses. Herein, we document statistical shortcomings in previous study design: for example, use of individuals who lack the ability to generate donor-specific-antibodies (HLA identical) as part of the negative cohort. We provide experimental evidence, using CRISPR-Cas9-edited cells, to rebut the claim that the HLAMatchmaker eplets represent “functional epitopes.” We further used unique sub-cohorts of patients, those receiving an allograft with two HLA-DQ mismatches yet developing antibodies only to one mismatch (2MM1DSA), to interrogate differential immunogenicity. Our results demonstrate that mismatches of DQα05-heterodimers exhibit the highest immunogenicity. Additionally, we demonstrate that the DQα chain critically contributes to the overall qualities of DQ molecules. Lastly, our data proposes that an augmented risk to develop donor-specific HLA-DQ antibodies is dependent on qualitative (evolutionary and functional) divergence between recipient and donor, rather than the mere number of molecular mismatches. Overall, we propose an immunological mechanistic rationale to explain differential HLA-DQ immunogenicity, with potential ramifications for other pathological processes such as autoimmunity and infections.</p
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