Empirical Studies in Hospital Emergency Departments

This dissertation focuses on the operational impacts of crowding in hospital emergency departments. The body of this work is comprised of three essays. In the first essay, Waiting Patiently: An Empirical Study of Queue Abandonment in an Emergency Department, we study queue abandonment, or left without being seen. We show that abandonment is not only influenced by wait time, but also by the queue length and the observable queue flows during the waiting exposure. We show that patients are sensitive to being jumped in the line and that patients respond differently to people more sick and less sick moving through the system. This study shows that managers have an opportunity to impact abandonment behavior by altering what information is available to waiting customers. In the second essay, Doctors Under Load: An Empirical Study of State-Dependent Service Times in Emergency Care, we show that when crowded, multiple mechanisms in the emergency department act to retard patient treatment, but care providers adjust their clinical behavior to accelerate the service. We identify two mechanisms that providers use to accelerate the system: early task initiation and task reduction. In contrast to other recent works, we find the net effect of these countervailing forces to be an increase in service time when the system is crowded. Further, we use simulation to show that ignoring state-dependent service times leads to modeling errors that could cause hospitals to overinvest in human and physical resources. In the final essay, The Financial Consequences of Lost Demand and Reducing Boarding in Hospital Emergency Departments, we use discrete event simulation to estimate the number of patients lost to Left Without Being Seen and ambulance diversion as a result of patients waiting in the emergency department for an inpatient bed (known as boarding). These lost patients represent both a failure of the emergency department to meet the needs of those seeking care and lost revenue for the hospital. We show that dynamic bed management policies that proactively cancel some non-emergency patients when the hospital is near capacity can lead to reduced boarding, increased number of patients served, and increased hospital revenue

Research reports: 1991 NASA/ASEE Summer Faculty Fellowship Program

The basic objectives of the programs, which are in the 28th year of operation nationally, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The faculty fellows spent 10 weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This is a compilation of their research reports for summer 1991

An integrated statistical model of Emergency Department length of stay informed by Resilient Health Care principles

Background Hospital Emergency Departments (EDs) face variable demand and capacity issues affecting timely discharge of patients. This is due in part to a lack of integration of routine monitoring data, affecting anticipation and response. Methods Patient flow was modelled (four hour target breaches; time to decision-to-admit; subsequent time to admit-to-hospital) in a busy ED. Patient and organisational data were collated, screened and conceptualised using Resilient Health Care (RHC) theory. Data were collected for all patients presenting during a 24-month period (May 2014–April 2016; n = 232,920) and analysed via multivariable logistic regression for four hour target breaches, and ordinary least squares regression for time. A measure of effect size was calculated for each independent variable. Overall model fit was assessed using percent concordant. Results Length of stay is related to demand, capacity and process indicators including: number of patients; night shift; first location being resuscitation or major injury area(s); urgent or very urgent triage patients; patients readmitting from up to 7 days previous; bed capacity; recent ambulance arrivals; and patients where the primary presenting complaint (PPC) is related to mental health or difficult to ascertain. Conclusions Understanding variation in performance through RHC theory can support staff and organisations in monitoring, anticipating and responding. A set of reliable core predictors has been identified to help design future ways to facilitate resilient performance through early indicators of pressure

Aerospace medicine and biology. A continuing bibliography (supplement 231)

This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1982

NUCLEAR POWER AND ELECTRIC GRID RESILIENCE: CURRENT REALITIES AND FUTURE PROSPECTS

Life as we know it in modern society relies on the smooth functioning of the electric Grid – the Critical Infrastructure system that generates and delivers electricity to our homes, businesses, and factories. Virtually all other Critical Infrastructure systems depend on the Grid for the electricity they require to execute other essential societal functions such as telecommunications, water supply and waste water services, fuel delivery, etc. This study examines the concepts of Critical Infrastructure and electric Grid resilience, and the role nuclear power plants do and might play in enhancing U.S. Grid resilience. Grid resilience is defined as the system’s ability to minimize interruptions of electricity flow to customers given a specific load prioritization hierarchy. The question of whether current U.S. nuclear power plants are significant Grid resilience assets is examined in light of this definition. Despite their many virtues and their “fuel security,” the conclusion is reached that current U.S. nuclear power plants are not significant Grid resilience assets for scenarios involving major Grid disruptions. The concept of a “resilient nuclear power plant” or “rNPP” – a nuclear power plant that is intentionally designed, sited, interfaced, and operated in a manner to enhance Grid resilience – is presented. Two rNPP Key Attributes and Six rNPP Functional Requirements are defined. Several rNPP design features (system architectures and technologies) that could enable a plant to achieve the Six rNPP Functional Requirements are described. Four specific applications of rNPPs are proposed: (1) rNPPs as flexible electricity generation assets, (2) rNPPs as anchors of hybrid nuclear energy systems, (3) rNPPs as Grid Black Start Resources, and (4) rNPPs as anchors of Resilient Critical Infrastructure Islands. The last two applications are new concepts for enhancing U.S. strategic resilience. Finally, a few key unresolved issues are discussed and recommendations for future research are offered. Study results support the overall conclusion that successful development and deployment of rNPPs could significantly enhance U.S. Grid, Critical Infrastructure, and societal resilience, while transforming the value proposition of nuclear energy in the 21st century

IPv6 Network Mobility

Network Authentication, Authorization, and Accounting has been used since before the days of the Internet as we know it today. Authentication asks the question, “Who or what are you?” Authorization asks, “What are you allowed to do?” And fi nally, accounting wants to know, “What did you do?” These fundamental security building blocks are being used in expanded ways today. The fi rst part of this two-part series focused on the overall concepts of AAA, the elements involved in AAA communications, and highlevel approaches to achieving specifi c AAA goals. It was published in IPJ Volume 10, No. 1[0]. This second part of the series discusses the protocols involved, specifi c applications of AAA, and considerations for the future of AAA

Possible harm from glucocorticoid drugs misuse in the early phase of SARS-CoV-2 infection: a narrative review of the evidence

none6noSince the publication of the RECOVERY trial, the use of glucocorticoid drugs (GC) has spread for the treatment of severe COVID-19 worldwide. However, the benefit of dexamethasone was largest in patients who received mechanical ventilation or supplemental oxygen therapy, while no benefit was found among patients without hypoxemia. In addition, a positive outcome was found in patients who received dexamethasone after several days of symptoms, while possible harm could exist if administered early. The right time interval for GC administration is still a matter of debate. Previous studies showed that an early GC use during the first phase of the disease, when viral replication peaks, may negatively affect the innate immune response through several mechanisms, such as the inhibition of pro-inflammatory and antiviral cytokine production and signaling pathway, including type I interferon, that is fundamental to counteract the virus and that was found to be impaired in several patients with life-threatening COVID-19. The GC misuse can lead to a more severe disease even in patients who do not have the established risk factors, such as obesity and cardiovascular diseases. In our focused review, we describe the role of immune response in viral infections, especially SARS-CoV-2, and discuss the potential harms of GC misuse in COVID-19.openSarzani R.; Spannella F.; Giulietti F.; Di Pentima C.; Giordano P.; Giacometti A.Sarzani, R.; Spannella, F.; Giulietti, F.; Di Pentima, C.; Giordano, P.; Giacometti, A

Clinical and Research Considerations for Patients with Hypertensive Acute Heart Failure

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

Empirical research in healthcare operations: past research, present understanding, and future opportunities

We examine the published empirical literature in healthcare operations management over the last 20 years. We note several unique characteristics of the research in healthcare operations, including a focus on operational and organizational variables, an interest in the underlying mechanisms that explain operational causal pathways, and an interest in economic and managerial implications. We organize the prior findings under five distinct themes: importance of operational variables, importance of volume, routing patients through healthcare systems, to err is human, and managing the improvement process. We also identify several key areas of future research, including personalized medicine, value based healthcare, and connected health. We conclude with a call to action for greater engagement with the medical community in areas where tools and insights of operations management can bring about improvements in healthcare delivery