Factors Leading to Rapid Response Team Interventions in Adult Medical-Surgical Patients

Rapid Response Team Intervention (RRTI) is a widely used intervention in acute care hospitals in the United States. Demonstrated effectiveness in preventing transfer to higher level of care or in decreasing in-hospital mortality has not been established. This exploratory study used a retrospective chat1 review to examine differences between medical-surgical acute care inpatients who had an RRTI and a control group. CutTent literature lacks information on proactive detection of patients who may be more likely to deteriorate and therefore require a Rapid Response Team Intervention. Therefore, this study\u27s PICO question was: Are there statistically significant differences between medical-surgical adult inpatients who required Rapid Response Team Intervention and those who did not for demographic characteristics and selected clinical parameters (vital signs, level of consciousness, etc.)? The chat1s of all RRT patients on three medical-surgical units in a community hospital for a period of one year were reviewed (n=135) with an accompanying chart review ofthree control patients for every RRT patient (n = 331 ). Variables included a descriptive set, the study hospital\u27s policy of cdteria for calling an RRT and other independent predictor variables. Results yielded five statistically significant differences between RRT and control 3 patients: age, history of psychiatric/mental illness, use of respiratory medications such as inhalers and steroids and use of medications to treat psychiatric/mental illness. There was a large variation in response time to criteria for calling an RR T . Abnormal vital signs were documented in the electronic medical record (EMR) but at times it was hours before the RRT was summoned. This variation in the reaction of the primary nurses caring for the deteriorating patient suggests automation of calling an RRT could improve patient care by reducing delays. There also is a need to increase awareness of the vulnerabi lity of psychiatric/mentally ill patients and chronic cardiac disease patients, and their greater likelihood of needing RRTI during hospitalization

Next Generation Experiments and Models for Shock Initiation and Detonation of Solid Explosives

Current phenomenological hydrodynamic reactive flow models, such as Ignition and Growth and JohnsonTang-Forest, when normalized to embedded gauge and laser velocimetry data, have been very successful in predicting shock initiation and detonation properties of solid explosives in most scenarios. However, since these models use reaction rates based on the compression and pressure of the reacting mixture, they can not easily model situations in which the local temperature, which controls the local reaction rate, changes differently from the local pressure. With the advent of larger, faster, parallel computers, microscopic modeling of the hot spot formation processes and Arrhenius chemical kinetic reaction rates that dominate shock initiation and detonation can now be attempted. Such a modeling effort can not be successful without nanosecond or better time resolved experimental data on these processes. The experimental and modeling approaches required to build the next generation of physically realistic reactive flow models are discussed. INTRODUCTION Phenomenological hydrodynamic reactive flow models, such as Ignition and Growth (1) and Johnson-Tang-Forest (2), have been very successful in predicting shock initiation and detonation in solid explosives. These models use compression and pressure of the reacting mixture in their reaction rate equations. The main experimental tools available to study shock initiation and detonation have been embedded manganin pressure gauges (3), embedded particle velocity gauges (4), and various applications of laser velocimetry, such as Fabry-Perot (5) and VISAR (6). Thus, when normalized to the measured pressure and/or velocity versus time data, the pressure and compression dependent reaction rates have been able to predict shock initiation and detonation wave propagation in one, two and three dimensions for most initial conditions in most applications. Of course, the modeling, especially in 3D, was limited by the size and speed of the available computers. With the advent of teraflop, parallel computers, these size and speed limitations have largely disappeared. The Ignition and Growth and Johnson-Tang-Forest reactive flow models are now being used on the large parallel machines. However, it has long been known that shock initiation of solid explosives is controlled by local reaction sites called "hot spots" (7) and that detonation waves have complex, 3D structures containing many Mach stem interactions (8). To model more exactly the physical and chemical processes that control reactions in solid explosives, the next generation of reactive flow model is required. The new generation of computers certainly allows such microscopic models to be built and tested in a timely manner. To really benefit liom these models, the next generation of experimental tools with improved spatial and time resolutions must also be developed. This paper discusses some of the properties that are desired in the next generation of microscopic reactive flow models and the associated experimental techniques. NEW REACTIVE FLOW MODELS Chemical reaction rates are always governed by the local temperature of the reacting material. Therefore, the local reaction rates in the heated regions which either ignite and form growing "hot spots" or fail to ignite due to conductive heat losses are intimately coupled to the physical mechanisms that create such heated regions. The next generation reactive flow models must accurately describe the physical processes (void collapse, friction, shear, viscosity, etc.) that form hot spots and the states (temperature, dimensions, geometry, pressure, etc.) that these hot spots attain. Various hot spot formation models have been proposed The usefulness of such modeling has been limited by both experimental and computational factors. The main experimental limitation is the lack of local time resolved temperature measurements. This and other experimental requirements are discussed in the next section. The main computational obstacle was the lack of coupling of thermal-mechanical codes to hydrodynamic codes. This obstacle has recently been overcome in the ALE3D, LS-DYNA2D/3D, and other hydrodynamic codes. This coupling has allowed modelers to study the hydrodynamic formation of hot spots using various dissipation mechanisms and heat transfer to the surrounding cooler material in 3D mesoscale meshes containing over one billion computational explosives using elements (12). Critical conditions for the subsequent growth or failure of the heated regions for HMX-and TATB

Noneconomic Barriers to Health Care Utilization by African-Americans

Many efforts have been made to maximize the utilization of health cue system. As a result the utilization of health care system by African Americans has increased, improving the health status (Blendon, Aiken, Freeman, & Corey, 1989). While some improvements have been made, recent reports show disparities between African Americans and Caucasians in the utilization of health care systems and in their health status. Barriers have been identified among those in the lower social economic status (SES). These barriers impede health care utilization and negatively affect health status. However, studies show that among some African Americans when health care is affordable and available, the utilization of health care systems is not maximized. This suggests there are noneconomic barriers impeding access to and the utilization of health care systems for some African Americans. This phenomenological study was based on Van Manen\u27s hermeneutic phenomenological approach (Van Manen, 1990). Data were collected from participants on their experiences gaining access to and utilizing health care systems. As data were analyzed, six themes emerged. These themes were: delay before seeking health care services, fear, distrust, quality of care, racism and long waiting time. Six of the original participants formed a focus group and through a dialectic process, gave meaning to the identified themes. Most of these themes continue to affect how African Americans gain access to and utilize health care systems

Next generation experiments and models for shock initiation and detonation of solid explosives

Current phenomenological hydrodynamic reactive flow models, such as Ignition and Growth and Johnson- Tang-Forest, when normalized to embedded gauge and laser velocimetry data, have been very successful in predicting shock initiation and detonation properties of solid explosives in most scenarios. However, since these models use reaction rates based on the compression and pressure of the reacting mixture, they can not easily model situations in which the local temperature, which controls the local reaction rate, changes differently from the local pressure. With the advent of larger, faster, parallel computers, microscopic modeling of the hot spot formation processes and Arrhenius chemical kinetic reaction rates that dominate shock initiation and detonation can now be attempted. Such a modeling effort can not be successful without nanosecond or better time resolved experimental data on these processes. The experimental and modeling approaches required to build the next generation of physically realistic reactive flow models are discussed

NASA's Current Evidence and Hypothesis for the Visual Impairment and Intracranial Pressure Risk

While 40 years of human spaceflight exploration has reported visual decrement to a certain extent in a subgroup of astronauts, recent data suggests that there is indeed a subset of crewmembers that experience refraction changes (hyperoptic shift), cotton wool spot formation, choroidal fold development, papilledema, optic nerve sheath distention and/or posterior globe flattening with varying degrees of severity and permanence. Pre and postflight ocular measures have identified a potential risk of permanent visual changes as a result of microgravity exposure, which has been defined as the Visual Impairment and Intracranial Pressure risk (VIIP). The combination of symptoms are referred to as the VIIP syndrome. It is thought that the ocular structural and optic nerve changes are caused by events precipitated by the cephalad fluid shift crewmembers experience during long-duration spaceflight. Three important systems, ocular, cardiovascular, and central nervous, seem to be involved in the development of symptoms, but the etiology is still under speculation. It is believed that some crewmembers are more susceptible to these changes due to genetic/anatomical predisposition or lifestyle (fitness) related factors. Future research will focus on determining the etiology of the VIIP syndrome and development of mechanisms to mitigate the spaceflight risk

THREE-DIMENSIONAL IGNITION AND GROWTH REACTIVE FLOW MODELING OF PRISM FAILURE TESTS ON PBX 9502

The Ignition and Growth reactive flow model for shock initiation and detonation of solid explosives based on triaminotirnitrobenzene (TATB) is applied to three-dimensional detonation wave propagation. The most comprehensive set of three-dimensional detonation wave propagation data is that measured using the trapezoidal prism test. In this test, a PBX 9501 (95% HMX, 2.5% Estane, and 2.5% BDNPA/F) line detonator initiates a detonation wave along the trapezoidal face of a PBX 9502 (95% TATB and 5% Kel-F binder) prism. The failure thickness, which has been shown experimentally to be roughly half of the failure diameter of a long cylindrical charge, is measured after 50 mm of detonation wave propagation by impact with an aluminum witness plate. The effects of confinement impedance on the PBX 9502 failure thickness have been measured using air (unconfined), water, PMMA, magnesium, aluminum, lead, and copper placed in contact with the rectangular faces of the prism parallel to the direction of detonation propagation. These prism test results are modeled using the two-dimensional PBX 9502 Ignition and Growth model parameters determined by calculating failure diameter and tested on recent corner turning experiments. Good agreement between experimentally measured and calculated prism failure thicknesses for unconfined and confined PBX 9502 is reported

Uses of Fabry-Perot Velocimeters in Studies of High Explosives Detonation

The Fabry Perot has become an important and valuable tool by which explosive performance information can be obtained relatively easily and inexpensively. Principle uses of the Fabry Perot have been free surface, and particle velocity measurements in one dimensional studies of explosive performance. In the cylinder test, it has been very useful to resolve early wall motions. We have refined methods of characterizing new explosives i.e. equation of state, C-J pressure, via the cylinder shot, flat plate, and particle velocity techniques. All of these use Fabry Perot as one of the principle diagnostics. Each of these experimental techniques are discussed briefly and some of the results obtained. Modeling developed to fit Fabry-Perot results are described along with future testing