223 research outputs found

    Polarization Observables for Two-Pion Production off the Nucleon

    Full text link
    We develop polarization observables for the processes γN→ππN\gamma N\to\pi\pi N and πN→ππN\pi N\to\pi\pi N, using both a helicity and hybrid helicity-transversity basis. Such observables are crucial if processes that produce final states consisting of a spin-1/2 baryon and two pseudoscalar mesons are to be fully exploited for baryon spectroscopy. We derive relationships among the observables, as well as inequalities that they must satisfy. We also discuss the observables that must be measured in `complete' experiments, and briefly examine the prospects for measurement of some of these observables in the near future.Comment: 20 pages, using revtex

    Self-care Barriers Reported by Emergency Department Patients With Acute Heart Failure: A Sociotechnical Systems-based Approach

    Get PDF
    Study objective We pilot tested a sociotechnical systems-based instrument that assesses the prevalence and nature of self-care barriers among patients presenting to the emergency department (ED) with acute heart failure. Methods A semistructured instrument for measuring self-reported self-care barriers was developed and administered by ED clinicians and nonclinician researchers to 31 ED patients receiving a diagnosis of acute heart failure. Responses were analyzed with descriptive statistics and qualitative content analysis. Feasibility was assessed by examining participant cooperation rates, instrument completion times, item nonresponse, and data yield. Results Of 47 distinct self-care barriers assessed, a median of 15 per patient were indicated as “sometimes” or “often” present. Thirty-four specific barriers were reported by more than 25% of patients and 9 were reported by more than 50%. The sources of barriers included the person, self-care tasks, tools and technologies, and organizational, social, and physical contexts. Seven of the top 10 most prevalent barriers were related to patient characteristics; the next 3, to the organizational context (eg, life disruptions). A preliminary feasibility assessment found few item nonresponses or comprehension difficulties, good cooperation, and high data yield from both closed- and open-ended items, but also found opportunities to reduce median administration time and variability. Conclusion An instrument assessing self-care barriers from multiple system sources can be feasibly implemented in the ED. Further research is required to modify the instrument for widespread use and evaluate its implementation across institutions and cultural contexts. Self-care barriers measurement can be one component of broader inquiry into the distributed health-related “work” activity of patients, caregivers, and clinicians

    Backward pion-nucleon scattering

    Get PDF
    A global analysis of the world data on differential cross sections and polarization asymmetries of backward pion-nucleon scattering for invariant collision energies above 3 GeV is performed in a Regge model. Including the NαN_\alpha, NγN_\gamma, Δδ\Delta_\delta and Δβ\Delta_\beta trajectories, we reproduce both angular distributions and polarization data for small values of the Mandelstam variable uu, in contrast to previous analyses. The model amplitude is used to obtain evidence for baryon resonances with mass below 3 GeV. Our analysis suggests a G39G_{39} resonance with a mass of 2.83 GeV as member of the Δβ\Delta_{\beta} trajectory from the corresponding Chew-Frautschi plot.Comment: 12 pages, 16 figure

    Clinical and Research Considerations for Patients with Hypertensive Acute Heart Failure

    Get PDF
    Management approaches for patients in the emergency department (ED) who present with acute heart failure (AHF) have largely focused on intravenous diuretics. Yet, the primary pathophysiologic derangement underlying AHF in many patients is not solely volume overload. Patients with hypertensive AHF (H-AHF) represent a clinical phenotype with distinct pathophysiologic mechanisms that result in elevated ventricular filling pressures. To optimize treatment response and minimize adverse events in this subgroup, we propose that clinical management be tailored to a conceptual model of disease based on these mechanisms. This consensus statement reviews the relevant pathophysiology, clinical characteristics, approach to therapy, and considerations for clinical trials in ED patients with H-AHF

    Clinical characteristics of emergency department heart failure patients initially diagnosed as non-heart failure

    Get PDF
    BACKGROUND: Since previous studies suggest the emergency department (ED) misdiagnosis rate of heart failure is 10–20% we sought to describe the characteristics of ED patients misdiagnosed as non-decompensated heart failure in the ED. METHODS: We analyzed a prospective convenience sample of 439 patients at 4 emergency departments who presented with signs or symptoms of decompensated heart failure. Patients with a cardiology criterion standard diagnosis of decompensated heart failure and an ED diagnosis of decompensated heart failure were compared to patients with a criterion standard of decompensated heart failure but no ED diagnosis of decompensated heart failure. Two senior cardiology fellows retrospectively determined the patient's heart failure status during their acute ED presentation. The Mann-Whitney u-test for two groups, the Kruskall-Wallis test for multiple groups, or Chi-square tests, were used as appropriate. RESULTS: There were 173 (39.4%) patients with a criterion standard diagnosis of decompensated heart failure. Among those with this criterion standard diagnosis of decompensated heart failure, discordant patients without an ED diagnosis of decompensated heart failure (n = 58) were more likely to have a history of COPD (p = 0.017), less likely to have a previous history of heart failure (p = 0.014), and less likely to have an elevated b-type natriuretic peptide (BNP) level (median 518 vs 764 pg/ml; p = 0.038) than those who were given a concordant ED diagnosis of decompensated heart failure. BNP levels were higher in those with a criterion standard diagnosis of decompensated heart failure than in those without a criterion standard diagnosis (median 657 vs 62.7 pg/ml). However, 34.6% of patients with decompensated heart failure had BNP levels in the normal (<100 pg/ml; 6.1%) or indeterminate range (100–500 pg/ml; 28.5%). CONCLUSION: We found the ED diagnoses of decompensated heart failure to be discordant with the criterion standard in 14.3% of patients, the vast majority of which were due to a failure to diagnose heart failure when it was present. Patients with a previous history of COPD, without a previous history of heart failure and with lower BNP levels were more likely to have an ED misdiagnosis of non-decompensated heart failure. Readily available, accurate, objective ED tests are needed to improve the early diagnosis of decompensated heart failure in ED patients

    What’s Next for Acute Heart Failure Research?

    Get PDF
    Each year over one million patients with acute heart failure (AHF) present to a United States emergency department (ED). The vast majority are hospitalized for further management. The length of stay and high postdischarge event rate in this cohort have changed little over the past decade. Therapeutic trials have failed to yield substantive improvement in postdischarge outcomes; subsequently, AHF care has changed little in the past 40 years. Prior research studies have been fragmented as either “inpatient” or “ED-based.” Recognizing the challenges in identification and enrollment of ED patients with AHF, and the lack of robust evidence to guide management, an AHF clinical trials network was developed. This network has demonstrated, through organized collaboration between cardiology and emergency medicine, that many of the hurdles in AHF research can be overcome. The development of a network that supports the collaboration of acute care and HF researchers, combined with the availability of federally funded infrastructure, will facilitate more efficient conduct of both explanatory and pragmatic trials in AHF. Yet many important questions remain, and in this document our group of emergency medicine and cardiology investigators have identified four high-priority research areas
    • …
    corecore